Home

Wastewater rehabilitation technology survey

1. 94 E 2 2 SCOPE OF 3 94 22 ce e 95 E24 SHOW TO GUIDE 95 E COST FORMULA 11 98 F 1 REHABILITATION TECHNOLOGIES COST ASSESSMENT 98 1 2 COST FORMULA 1 98 2 1 CONVENTIONAL TRENCH 99 F 2 2 SHORING AND TRENCH 99 F 2 3 25 99 2 4 eade en ee 100 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE E235 ROBOT bbLds 100 2 6 SHORT LINERS riter eei tei bee c 100 F 2 7 MAN MADE 5 100 F 2 8 CURED INIPLACE PIPES 101 F 2 9 HORIZONTAL DIRECTIONAL DRILLING 101 USER MANUAL FOR THE REHABILITATION TECHNOLOGIES DB 102 F 3 1 GENERAL DESCRIPTION REHABILITATION COST 102 F 3 2 SCOPE OF APPLIC
2. 26 C 1 2 3 2 with mortar and plastet ee rte EHE eri ED 27 23 3 sssi 27 C1234 ee 28 C1233 116111 601 28 C 1 2 3 6 PIC CASE 101 670168 s istas niea iran Guten titu aeee sisne 29 COMPUTER AI DED REHABILITATION OF SEWER NETWORKS CARE C124 01060008 1601008 c m 30 C 1 2 4 1 Chemical stabilization fill and drain systems eese 30 C 1 2 4 2 31 30111666311118 31 1244 Resin mee aee o ERE 33 12 435 COmpacted MINE isss isinara 23 C 1 2 4 6 Surrounding stabilization 34 C 2 RENOVATION TECHNIQUES 35 ssscecsscnsssessesssenss EAE NOS ERE YPERENEER RR REPE REPRE EENER PS UNE E eV se 36 CAL DIG TECHNOLOGY eM 36 Sex MES E Te r E R AE 36 Conventional trench R E 36 C2 L2 RETE 36 C 2 1 2 1 Shoring and Trench box modificated 444221 36 A 2 1 2 2 Conereteshest pile eene pedale 36 SUN NES MER I ep
3. coven m oa ta sarang Lakes ot pem Maru eroding see regeret ach mile of prt ane worst seg tions et Sayre JPoasay zl Rear ran rrr h chang etait day Mame for sum lana cese 50 a ot Snapo ved avista of Tectmoropy n vuole malen ince detect naung connecten wag Nadah Mal urged H tow Renew e p je me ana een see trends to EN 1524 jets ferro fasse assz fassa farts fesse dotar este asas E He BH T 7 5 T A of habian meh of ean a wits bate Pete asen siredy io taii romances n n i cw nb sh 8 alallala 20
4. eode F2 zia 2 20 a fa 5 a 2 a o 3 2 Sp Sl ele Jelelelelelelelefejeiededete lele elzleteteted Eis a ja a ata sj aa lala a Va essi ona xara orma o COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE E REHABILITATION TECHNIQUES DATA BASE 1 RT data base description The result of the rehabilitation technologies survey has produced over 50 different techniques and for each one of them 30 characteristics have been defined This makes quite a pretty amount of information that must be organized properly to make it usable and useful CARE S target requires among other large amount of information and calculations access to the available techniques and their main characteristics This information must be available in a dynamic way that is data must be stored in a easy to query file organized and arranged This is an important issue because the aim of this surveying task is not just to establish a list with the state of the art of rehabilitation technologies but provide a useful tool to other tasks developed in the CARE S project The
5. 85 25 1 13 69181 of NeW 86 D 2 2 4 Hydraulic performance after rehabilitation 86 2222 Wee POAT SRC Se Lem URS 87 D 2 2 6 Need of previous cleaning 87 D 2 2 7 Need of digging for reconnecting laterals 88 D 2 2 8 Requires later re opening of laterals connections eee 88 D2 2 9 Possibility of work interruption 88 D 22 10 Requires in a baad 89 C rvat re 3110166 end tien cg las oh cet 89 D2212 11211 89 D 2 2 13 Estimated lifetime of rehabilitated 2 89 D 2 3 ENVIRONMENTAL IMPACT 90 D 2 3 1 Structural impact on the surrounding buildings or networks 90 D 2 3 2 Environmental impact of materials and Works sees 90 D 2 3 3 Impact on groundwater quality uode rei arene 90 D234 Acoustic pollution 90 gs Me vigiliis c 90 E REHABILITATION TECHNIQUES DATA BASE E 1 RT DATA BASE DESCRIPTION 5 5 5 thao sese eese eee e teen asses e eese eaae eee 92 E 2 USER MANUAL FOR THE REHABILITATION TECHNOLOGIES DB 94 E 2 1 GENERAL DESCRIPTION THE REHABILITATION amp OPERATIONAL TECHNOLOGIES DATABASE
6. Settled deposits LE fons ie gud 8 mE BED Ingress of soil C 62019 egay sy 1 2 06 110 aD ininvert invet 036207190101666 lt ding through the wall 1028 1 jwededinfejont 20101200 pipe extemal pipes or cables built through sos infiltration A wein 1 0 4 8 jdpg c fwg D D 9889 d BBG Exfiltration Visible leakage of flow out of the LB fnamn 1 1 5 jdammedsubsufacewater ee es 12 COMPUTER DED REHABILITATION OF SEWER NETWORKS CARE REPAIR RENOVATION REPLACEMENT Codes relating to the fabric of the pipeline Codes relating to the operation of the pipeline Code according to prEN 13508 2 BAA BAB BAD BAE BAF BAG BAI BAJ BAM BAN BAO BAP BBA BBB BBC BBD BBE BBF BBG BBH 5 5 s 5 8 4 5 5 o tis g 4 5 5
7. eee 36 22 TRENCHLESS TECHNOLOGY 36 Bv Coating MONE Em 36 C2211 Reinforced 60600015 ossium pci 36 2 2212 Steel reinforced cement mortar Spray lu 37 C 2 2 1 3 Fibers reinforced cement mortar spray rtr S Det neutre 38 22 14 Polymer Iming 39 2 2 2 E a RE Oe boim d tas 40 C222 Swased mers swageling 40 C 2 2 2 2 Folded liners fold amp form 42 APA NIE 43 2 2 31 Continyous 81011101118 aou epu edd cage 43 5 2222 116 6 siu ch 44 222 S egment l 5110101118 serria aeir 45 2 2 4 Spirally wound 46 C2241 Spiral 11111118 46 C 2 2 5 Cured in place lining CIPP or soft reversion lining 48 2 2 9 1 61 0 006 nr 50 225 2 Hot Water CUTE a sb acta ated 50 25 2 Steam rf hot aif CUTE MH 50 C2294 UV CU C TR 50 C 3 REPLACEMENT TECHNIQUES esssesesocesoocss
8. H E 2 s lc 4 51 5 5 5 g 5 5 5 2 Ei 8 8 8 2 81 2 F3 L4 8 5 8 58 3 8 E o j 8 B s2 gs 8 5 E s 8 8 2 8 32121813 2 55 E 8 5 ls ES 2 8 sS8 2 5 E 5 2 5 5 Technology 28 8 Ela 21551 5 s conventional trench 1 011 2 1 2 1 0 0 2 2 0 0 2 2 2 2 0 0 0 2 0 2 2 2 trench box 1 031 2 1 2 1 0 0 2 2 0 0 2 2 2 2 0 0 0 p 0 2 2 concrete sheet pile o 0 0 87 sheet pile steel 1 2 1 0 0 0 0 2 0 0 0 0 2 2 injection in joints cracks or fractures pi 0 1 2 1 1 0 0 0 0 0 0 2 2 milling robot mortar pipes joints 0 0 0 0 0 0 1 0 2 1 1 1 0 0 root cutting robot repair operational 0 0 0 0 0 0 0 0 2 0 0 0 0 0 1 0 2 2 1 0 1 0 0 0 0 0 2 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 patch repair conventional trench concrete sheet pile sheet pile steel pipebursting percussive Pneumatic pipebursting hydraulic pipebursting static pipe crusing implosion pipe ejection modified pipe jacking pipe extraction modified static pull pneumatic hammer hydraulic hammer steerable moling pipe ramming impact
9. inar arated win packers oe marata ijah f aa rE 1 cug cturnet angor bene SENE 011123211318111 2111111111418 0 8 dd 8 8 2 7 22111 1711711111 RARARRAREREERAE my Ep m ER lale ele a aea a ja 5 Por tne ate Lew 4 of Income darmi 345 B alo E am nodi oF cohabeeaten in nich er pari a tha tabik v b o De 01 and fs pastorace b E t 0 5 KE 11440 11411 Bot n PUHEEN Bl muy fsa eh ct 197127 1 3 y iino lee reversion barg IPP Pak wae care eure 181715 151718 r1 sa aa aja a dee eS elel ale ajo pede 20 z 5 of mew anum tha abt on eter haf baie De etu Fence 79 enerala waa Be gal eal amy any 2g 1002 ERA BES 33 1355 8 57 1 341455 24544 145414 345454 345414 3454
10. 104 COMPUTER DED REHABILITATION OF SEWER NETWORKS contains cost formulae Figure 6 with a maximum number of 100 techniques considering two possible costs for each of them such as day night or summer winter Every element is definable by the user or it can be adopted as CARE S default Pipe Trench Trench Presence Presence Default Name length width depth of hard of difficult ies Dewatering ew project unit 2 m soil h cost list t Hc tit E CitylNo Street LE d Street GardensiGra No City Street Street City Figure 5 Cost drivers table In the cost drivers table every cost driver has a Name a Type FLOATING point number or a State coming out from a LIST this option can be used for distinguish numeric variable such as diameter length width etc from list variables such as need for dewatering working surrounding etc Lists can contain up to ten elements a Demo Value that is used in the formulae table to obtain a numerical result allowing the operator to test formula consistency during editing phase an Operation state that can be default if the cost driver is defined by CARE S or save if the cost driver is user defined This switch is used for selecting the use of CARE S defaults or for defining new variables and values The cost drivers are c
11. 86 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE the decreased roughness of the new pipe material the global effect in the hydraulic capacity can be considered null o The roughness is due to inner surface material Most renovation techniques use plastic pipes HDPE PVC polymers etc so that concrete and brick pipes reduce their original roughness while plastic pipes keep similar values Some techniques use concrete as new material in these cases concrete old pipes restore its original roughness Concrete solutions are not usual in old plastic pipes o The slope in general slope can only be changed in off line replacement methods Other rehabilitation technologies do not change this paramenter and thenthe influende in the hydraulic capacity is null except for off line replacement methods and CLG system CLG controlled line and grade is a on line replacement technology that allows small changes in the direction and grade of the sewers generally intended for correcting sags This technique is not very common As a final consideration it should be pointed that the objective of a rehabilitation is not to provide more hydraulic capacity to a sewer length that is under dimensioned but to give back the original level of service to a deteriorated conduit including also the hydraulic level of service So rehabilitation is not to increase the hydraulic capacity but to restore the lost capacity D 2 2 5 Digging requir
12. Generally the contractor shall adopt slow pumping rates in order to maximize mortar intake and to ensure against occurrence of hydraulic fracturing The pumping or mortar injection rate recommended is 0 03 m3 per minute or lower The maximum limit pump in pressures recommended is 1 bar 0 1 MPa near structures In the case of damaged sewers this limit shall be reduced to 0 5 bar 0 05 MPa Generally mortar injection shall commence around the perimeter of the treatment zone and then proceeding toward the center Each hole shall be drilled and grouted before moving to the next hole In the case of multiple cavities or multiple limestone layers in any drill hole treatment shall proceed from the lowest cavity and completed for that cavity before proceeding to the next higher cavity Operation is finished when shafts are back filled compacted and repaved Benefits v Improves general soil stability v If it s carefully designed and taken can be an structural technique Drawbacks x There s risk of surface for settlement or heave over so monitoring of surface is highly recommended Doesn t repairs directly the sewer Surface damage is produced and digging required although only in few locations Requires soil characterization Difficult to measure in the project To complete sewer repair other techniques like fissure sealing are required xXx xxx C 1 2 4 3 Joint sealing Sealer injection Technique for r
13. water velocity o chemical abrasive products poured to sewer networks Process sewer is cleaned the water canalized in small pipes or pumped and sewer length is provided with electric light 28 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE preliminary task of demolition and extraction of damaged elements is done The operative reconstructs the defective zone makes sewer slope uniform and then reconstructs the invert with bricks and mortar Otherwise a formwork is placed to form the channel and the benchings and concrete is pumped it The auxiliary installations are taken away once the masonry or concrete work has set up The sewer is back to service The auxiliary installations are taken away and the sewer is back to service Benefits v Very useful for invert collapses v Structural and sealing technique v surface damage is produced No dig required v Very low social cost as few traffic disturbances noise or dust produced Drawbacks x Only suitable for concrete or brick sewers Only suitable for man entry sewers Many security and health measures to be observed Many powerman required that can increase the cost Relatively slow process quite slow if invert is reconstructed with bricks 1 2 3 6 Pre cast invert repair The difference with in situ invert repair is that pre cast technique uses precast elements usually half pipes to re
14. hydraulic benefits WP3 mechanical benefits and durability WP2 and economical issues WP7 This task will generate report D12 Wastewater on rehabilitation technology survey A 3 This document Here it s presented deliverable D12 that shows the results of task 4 2 The content of this document has been divided in several parts Part A Framework for WP4 CARE S project and introduction Part B Description of the objectives of this document Part C Detailed description of Rehabilitation Technologies for pipes manholes and lateral connections Part D Description and presentation of the Rehabilitation Techniques Chart that summarizes the main characteristics of the RTs Part E Rehabilitation Technology Data Base Description and end user manual Part F Cost formula calculation and end user manual Part G References Part H Annexes 12 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE B OBJ ECTIVES B 1 Report D12 objectives The aim of this document is to present a description of all techniques and methods available for sewer rehabilitation with their main characteristics To make the rehabilitation techniques RTs operative they have been presented in different formats gt Part C of this report presents a definition for each RT together with a schematic outline of the installation process This brief explanation aims to make more comprehensible the technique but
15. obstacles dislocation abrasion corrosion pipe breakage and collapse The removal or even the prevention of this damage can be achieved by sewer rehabilitation 15 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE According to European standard EN 13566 1 the definitions for the three main groups in which sewer rehabilitation is divided are Repair rectification of local damage Renovation work incorporating all or part of the original fabric of the pipeline by means of which its current performance is improved Replacement rehabilitation of existing pipeline system by the installation of a new pipeline system without incorporating the original fabric Similar definitions can be found in WRc Sewerage Rehabilitation Manual Hepair rectification of damage to the structural fabric of the sewer and the reconstruction of short lengths but not the reconstruction of the whole pipeline Renovation methods by which the performance of a length of sewer is improved by incorporating the original sewer fabric but excluding maintenance operations such as root or silt removal Replacement construction of a new sewer on or off the line of an existing sewer The function of the new sewer will incorporate that of the old but may be also include improvement or development work In the last decades the rehabilitation technological market has developed quickly This growth has been even more tangible in the d
16. to be fed in during the process to surround the pipe Process steel blade and pipe box are pulled through the ground using a tractor or other pulling vehicle and an additional winch unit As the plough passes the ground is opened creating a vertical hollow allowing the pipe to be inserted pipe must be flexible enough to be fed over the top of the mole plough and guided into position through the pipe box The slot cut by the plough is so narrow that it virtually closes over the cable and few space work is required afterwards 80 of the settlement is achieved by gravity and natural relaxation of the soil In some cases a tracked vehicle or vibrating roller are used to assist ground compacting 51 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Benefits v Rapid installation rates v Low cost v Few disturbances to citizens v Suitable for the rural sides of the roads or highways Drawbacks x Not suitable for hard or rocky soils x Notsuitable if surface is paved x Other services will slow down the process Only short depth achieved 2m Only suitable for very small diameters and slightly flexible pipes C 3 2 Trenchless technology C 3 2 1 On line replacement C 3 2 1 1 Pipe bursting percussive pneumatic Pipe bursting methods Pipe bursting is a trenchless technology that replaces a sewer by breaking and displacing the existing pipe and installing a rep
17. 1 2 4 Grouting methods C 1 2 4 1 Chemical stabilization fill and drain systems Fill and drain methods are used for sealing cracks and cavities in structurally sound sewers by chemically treating a length of sewer between manholes Chemical grouting is a technology primarily used for spot repairs to seal joints and non structural cracks Chemical grouting reduces or stops water infiltration and exfiltration The chemical grout builds up an external flexible and impermeable mass in the soil surrounding the spot repair location Chemical grouting is used primarily for cracks in pipes at leaky joints and in access holes Process sewer section between manholes is isolated and cleaned Manholes and laterals are closed off chemical solution is pumped into the sewer This solution seeps through defects into the surrounding ground first solution is pumped out and a second introduced Reactions between the two solution the surrounding ground cause solidification and leakage prevention sewer is re cleaned before being put back into service Benefits v It is a cost effective method to stop water infiltration by filling voids and sealing fissures in fractured soil v It can prevent future structural damage Can re use unmixed chemicals Provides structural enhancement although difficult to measure through the stabilization of the existing pipe fabric and the surrounding ground Suitable for no
18. 311850 1002 1 2 3 6 pre cast repair 54000 81000 1002 1 2 4 2 mortar stabilization 207900 311850 1103 1 1 1 1 conventional trench 117000 175500 1 shoring and trench box 297000 445500 1103 98 concrete sheet pile single 550000 825000 1 1103 1 2 1 2 milling robot 1200000 1800000 1103 1 2 1 3 root cutting robot 12000 18000 11031231 masonry 94245 141368 1103 1 2 3 4 injection 138600 207900 1103 1 2 3 6 pre cast repair 108000 162000 41013472429 mortar ctahilizatian qaaRnn nzann Figure 4 Result presentation The results table contains every pipe first column and every rehab technology that can be computed with the available information second and third column with the relative costs two columns in general containing day night costs or Summer Winter costs or the extreme values in a possible cost interval F 3 5 Cost tool default data files and customization As the tool is totally user definable costs selection will be a user decision and the relative formula will be added by the user in the RT formulae definition spreadsheet The tablet button in the toolbar the second button in figure 1 allows for the definition of cost drivers and formulae Clicking on it a new spreadsheet is revealed in the workbook formulae The spreadsheet is composed by two parts the first table on the left contains the cost drivers Figure 5 with a maximum number of variable equal to 20 the second table on the right
19. 5 2 Hot water cure Benefits v Simple installation although requires cauldron Drawbacks x Slow curing process nevertheless is quicker than ambient cure C 2 2 5 3 Steam or hot air cure Benefits v Quite quick curing method Drawbacks x Requires special equipment x Risk of folding in large diameters In this case hot water curing is recommended C 2 2 5 4 UV cure Benefits v Quickest curing method Drawbacks x Requires UV lamp robot that makes high cost x f diameter is medium or large D gt 500mm liner walls thickness is larger and so curing process may not reach inner part of the layer 50 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Replacement techniques C 3 1 Dig technology C 3 1 1 Open cut C 3 1 1 1 Conventional trench See 1 1 1 1 C 3 1 2 Semi open cut C 3 1 2 1 Shoring and Trench box modificated shoring See 1 1 2 1 C 3 1 2 2 Concrete sheet pile See 1 1 2 2 C 3 1 2 3 Sheet pile See 1 1 2 3 C 3 1 2 4 Mole ploughing Method of installing a pipeline by pulling a plough through the ground whilst a continuous length of flexible pipe is fed into the top of the plough and buried in suitable terrain from the tail This method is useful for small diameters so it s commonly used for installing water and irrigation mains electrical and telecommunications ducting Adaptations to the system such as hoppers attached to the pipe box enable bedding materials
20. 55 79 D 2 COLUMNS CHARACTERISTICS sssssssscsscscessscecsaceceasecsceacecessecsscnsesessesenceseacsceceacs 79 D 2 1 APPLICABILITY CONDITIONS OR REQUIREMENTS eene eene 79 Kind oue rodeo nan e p pactot 79 D 2 1 2 Technology applicable to sewers manholes laterals 8l D 2 1 3 Diameter of existing lippus tae stad equis 81 D 2 1 4 Shape and visitability of existing sewer eese 81 D 2 1 5 Suitable material of existing 6906 82 D 2 1 6 Structural sealing technique 82 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE D 2 1 7 Diameter or cross section after rehabilitation 83 D 2 1 8 Need to cut off temporally the service connection 83 D 2 1 9 Application under groundwater level or leakage admissible 83 D2 LIO Suitable kind OP SUL 84 D 2 1 11 Working area fequired ine io xe 84 132 2 TECHNOLOGY ind ra ie bites 85 D 2 2 Maximum length from each loeation ueniret Lern 85 0 2 2 2 Performance of the technology estet epit ee teet
21. 87 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE A clean sewer is required by some techniques which effectiveness may be affected by attached deposits and dirt over pipe walls in different grades Cleaning operations have been divided into categories No cleaning required to carry out the works Light cleaning necessary before starting the works Heavy cleaning must be done prior to develop the rehabilitation Heavy clean and dry for those techniques that can t be used in wet pipes O0 0 This cleaning operation should be considered when assessing direct cost D 2 2 7 Need of digging for reconnecting laterals Lateral connections are the conduits that connect the sewer network with the buildings and inlets If these connections are done along the pipeline and not in the manholes access to connection points is limited even more in no man entry sewers When rehabilitating a pipeline it s usual to cover these connection points sometimes to ensure that the main conduit is going to keep more or less dry and sometimes because the new pipe just blocks out them The reconnection of these lateral connections can be achieved with the help of a drilling robot in no man entry sewers and its consequent increase of prices or it can be hand made by operatives inside the sewer if the size of the conduit is big enough But some techniques as the trench and the replacement methods don t allow this later reopening either becau
22. 93 223 02 33 www clabsa es Work Package 4 task 4 2 Delivery D12 http care s unife it
23. 96 Kind of defect solved BAD BAE BAF BAG BAH BAI BAJ BAK BAM BAN BAO BAP wa f a s N w Codes according 1 082 Help 0 DEFECT CODES T EN 1LI308 2 are Pane Breet bo papa Cresc Lie o connection connection Sarah dal viibi hz detect Boo Tatier dapni bam of r Gather abades titration BRSRHRBEEPEEREEERRREREE d COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE List facility For quick access to a technique in the DB the list facility has been developed To use it 1 Click on List all techniques on the menu box 2 Double click the desired technique to go to its file Edit facility When accessing the rehabilitation files using the search engine or the list facility data are not made editable in order to avoid information damage To edit the rehabilitation files you can use the edit function Please note that Access does not allow the undo function so a back up of the database before editing is recommended P
24. Benefits v Useful for small defects v Good quality control for factory prepared liners v Some can tolerate some infiltration during application v surface damage is produced No dig required v Very low social cost as few traffic disturbances noise or dust produced v Quick total working time Drawbacks Only suitable for circular sewers Poor quality control for site impregnated liners Shrinkage of liner during cure can result in displacement at lateral services High level of operator skill required x x x x C 1 2 2 2 Metallic Another kind of short liner is the metallic joint sealing that involves the installation across the joint or defect of a metal band or clip faced with an elastomeric material which forms a seal with the inner surface of the pipe Process It s the same than for rerounding stainless steel sheet is wrapped around an expander assembly is inserted into position the sewer 25 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Expansion to the required diameter is carried out The clip is left in position and the expander retracted Benefits Atle Does not uses chemical so it s environmental safe Good quality control Can be used in small as well as in large diameters Can provide structural repair No surface damage is produced No dig required Very low social cost as few traffic disturbances noise or dust produced
25. CLG Controlled Line and Grade System is a pipe replacement method derived from pipe bursting methods with ability to correct sags humps or misalignments in existing pipelines Process A steel rod string that consists of short steel rods coupled together is inserted through the existing pipe along its entire length The rod string is precisely aligned to the desired line and grade in insertion and reception pit and anchored in tension A light cement slurry is pumped in to fill the pipeline and any open voids around it Once the cement slurry is cured between 4 to 24 hours a bursting head and a replacement pipe are attached to one end of the rod string The rod is then pulled out towing the new pipe behind it A bentonite lubricant may be supplied to reduce the pulling force required for the operation The bursting advances through the cured slurry encountering equal resistance from the cement existing pipe and ground envelope at all points around its face and circumference Because of that the bursting head is not as likely to be deviated from its path and is less affected by sags misalignments and undulations in the old sewer pipeline The cured light cement provides the support and a shield against shards from the old burst pipe rocks and harmful objects in the pipe zone The described method is modified under the following conditions When larger pipes are being replaced generally 400mm and larger a boring tool is substitu
26. Fast installation times Drawbacks x x The cost of the materials is however higher than for cured in place methods The repair length is limited by the size of clip which can be inserted from a manhole because the repair clips have no longitudinal flexibility Not suitable for non circular sewers 1 2 3 Man made repairs C 1 2 3 1 Masonry Masonry or brick works consist on hand made reparation with bricks and mortar The bricklayer does the work inside the sewer so one of the limitations for this method is that inside repairs are only possible in man entry sewers Otherwise dig technology can be used Process The sewer is cleaned the water canalized in one small pipe of 200 300mm diameter or pumped and sewer length is provided with electric light Usually a preliminary task of demolition of damaged elements is necessary The operative reconstructs the defective zone with bricks and mortar The auxiliary installations are taken away once the masonry work has set up The sewer is back to service Benefits S A lt Very adaptable method Material is employed only where needed Structural method Sealing method Quite simple and cheap devices and materials employed No surface damage is produced No dig required Very low social cost as few traffic disturbances noise or dust produced Drawbacks x x x Only suitable for man entry sewers Many security and health measures to be o
27. Grade system its rare use 98 COMPUTER DED REHABILITATION OF SEWER NETWORKS CARE for sewer pipes e g mole ploughing or in some cases the complexity of the works that require an specific study of the cost for each location e g tunneling with shields Finally just warn once more time that next formulae are just a guidance obtained from data of different countries and consequently may present a significant dispersion regarding to single local conditions F 2 1 Conventional trench Cost driver formula Cost default cost diameter depth Xdrivers length COST DRIVER VARIABLE VALUE Depth Depth 1 5m 1 3 2 4 5 3 6 4 26 5 Presence of hard rock Diameter lt 300 mm 40 yes lt 700 70 gt 700 120 Difficult soil yes Diameter lt 300 mm 7 lt 700 15 gt 700 25 Working surroundings Street 50 City 50 City street 100 Reinstatement of pavement Street 120 surface Grass 60 Dewatering yes Diameter lt 500 mm 30 lt 1000 40 2 1000 50 F 2 2 Shoring and trench box Project price cost driver formula Cost conventional trench cost 30 length depth 2 Shoring price 30 m2 100 shored F 2 3 Concrete sheet pile 99 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Project price formula Single discrete boring holes pilling 50 4 3 depth 2 length Sheet pile 170 length depth 70 length Digging earth transport dumping 11 lengt
28. Inter jack stations are not practical in pipe diameters less than 1 meter as they must be dismantled and removed from the pipeline when jacking is complete Process remote control tunnelling machine consist of a shield which is used to excavate a bore tunnelling machine is pushed horizontally into the ground from the drive pit by hydraulic jacks range of cutting heads is available for the tunnelling shield these may be fitted with blades picks or disc cutters depending on soil conditions n addition to the techniques common to pipe jacking for spoil removal vacuum pressure is also used to suck spoil away from the head and back to tanks on the surface Benefits v Curved bores can be produced v Line and level of pipe can be controlled v Safe tunneling option under favorable conditions because workers and the public are not directly exposed to hazardous conditions 70 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Less noise and traffic disruption than conventional trenching Precise installation Also suitable in wet conditions and marine crossings Faster rate of progress than conventional tunneling lt lt lt lt Drawbacks Large pits necessaries depending on diameter Thorough site investigation required Boulders can halt installation High capital cost of equipment Requires highly skilled operatives x x xx x C 3 2 3 8 Minitunneling Mini tunnels are co
29. It s defined as man entry the sewer that measures 160cm high or more and 60 cm of wide As it has been explained before local regulations may change these values and the end user should adjust this in the Rehabilitation Technology Data Base Shape and visitability are independent variables and according to previous definition circular pipes are only considered man entry for diameters of 1600mm or over Even though it s usual 81 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE to consider pipes of 1500mm as For inspection purposes minor measures of sewer may be considered fair and so it can be introduced the concept of partly man entry sewers with a minimum measures of 100cm high and 50cm wide These conduits may admit visual inspections in favorable conditions low flow not steep For rehabilitation works inside the sewer this should be man entry D 2 1 5 Suitable material of existing sewer Many rehabilitation techniques are only suitable for specific sewer materials as fragile or at least not ductile and consequently some techniques will be discarded if the existing sewer material is not listed Replacement techniques inform in this field the material for renewal sewers in this case this is in general not a decisive condition Materials considered are coded according to next list stone brick vitrified clay concrete reinforced concrete asbestcement ferro cement glassfibr
30. about rehabilitation technologies and e the information source on rehabilitation technologies for use in the Multi Criteria Decision Tool for selection of technologies For the latter point a list of techniques is suggested which are able to solve a specific defect s in the sewer or drainage system under defined environment conditions and dimensions see Applicability conditions or requirements This database also provides data for the calculation of socio economic costs like the environmental costs see Environmental impacts the disturbance to citizens working area required time to develop the works etc and others see Technique rates and characteristics 94 COMPUTER AI DED REHABILITATION OF SEWER NETWORKS E 2 3 Data In order to use the ROTs DB the user must have MS Access installed on their computer Basically this is a data provider tool It can and should be modified according to end user preferences and utility specific information as information about available technologies and their characteristics may differ from one country to another It can also be updated with techniques which are not present in the DB Complete information of 7 technique is stored in single files or file cards structure meaning of each field is explained in ee es a mmm er oam d RE t the report technolo
31. can be supplied x Sufficient site space is required to accommodate butt fusion welding of pipes before the diameter reduction and during insertion x Sometimes the reversion process may be completed fully x Theliner may move in relation to the host pipe due to stresses that may be developed in the liner e g due to thermal expansion or contraction x liner cannot be used in bends of more than 45 x For full structural applications the folding and re rounding process of the installed liner must be carefully monitored to avoid long term liner problems 42 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Pre grouting may be necessary in damaged areas or where there are voids Only circular cross section pipes can be lined Host pipe needs surveying cleaning and preparation Tight radius bends have to be cut out Lateral connections have to be excavated or robotically re opened A single diameter liner cannot cope with a major size change in host pipe bore Kk 2 2 3 Sliplining C 2 2 3 1 Continuous sliplining Simple slip lining typically comprises either a continuous or jointed discrete lengths of pipe are pulled or pushed through the existing pipe Sliplining creates a new pipe inside the old sewer without a complete excavation PVC and HDPE high density polyethylene pipe is primarily used in sewer sliplining applications With PVC pipes joints are traditional push on jo
32. diskette icon The formulae spreadsheet disappears and the user returns to RT cost spread sheet F 3 6 Cost tool file management and copy paste procedures The fourth button in the toolbar with a spreadsheet icon will start the file manager tool As the information about cost formulae and cost drivers can be changed by the user a tool is needed for helping the user to copy and paste formulae between different cost tool files If the user wants to take the formulae from another project or generally from other cost tool files that he has used in the past he can run the file manager as it will be described in the following Figure 7 shows the File manager form that is constituted by a selection box and four buttons At the beginning only two of them are active the Remove and the Select buttons The Select button opens a file box in order to select the files that the operator wants to use for loading or saving cost formulae Vice versa the Remove button is used for cancelling a file from the dropdown list of possible selections Rehabilitation cost formulae selection Figure 7 File manager 106 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE MCipollaDicFeb03 xls McCipollaDicFebO3 xls Remove Select Figure 8 Dropdown selection list of cost tool files When a file is selected it appears in the dropdown list and the Load Save buttons are activated Figure 8 Th
33. interruption of service may be sometimes impossible others inconvenient so that this characteristic may become sometimes a decisive factor for the sewerage manager D 2 1 9 Application under groundwater level or leakage admissible This field provides the information of the requirements of watertightness of the RT under two different scopes e lf the technique is applicable under the watertable In this sense trench technologies are considered as suitable because in general the water in the trench can be 83 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE evacuated by means of small pumps and working in this conditions is acceptable and even quite usual as this does not represent a technical problem e f significant infiltration is admissible during rehabilitation works This aspect is more addressed for no dig technologies D 2 1 10 Suitable kind of soil Soil surrounding does not compromise the suitability of most rehabilitation techniques but in few cases techniques should be carried out in favourable soil conditions This can be different for diverse techniques and so drilling technologies require cohesive soils but present very low performance in rocky soils This does not intend to force sewerage manager to invest in large geological data collection campaigns in a master plan phase More simple information is only requested and experience and knowledge of the territory by managers is usually enough for the pu
34. into the tail gap From a more general standpoint several developments have been devoted to the design of mixed shields that would be capable of handling a variety of heterogeneous materials which are often found in urban areas and usually result in major tunneling difficulties Even though the universal machine is yet to be invented concepts such as the mixed shield can help in adjusting to the variety of grounds encountered along a tunnel alignment particularly at shallow depth Advances in the shield technology have allowed significant improvements to be made in terms of ground motion control and tunneling induced settlements can now be kept under relatively 73 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE low values in comparison with previous records Significant experience has also been gained over the past years in shield operation know how As a result and provided an appropriate machine is selected and skillful workmanship is available high performances should be expected for most shield tunneling jobs with limited impact on the environment compared to open trench digging Ground collapse may however be experienced even when using the most elaborate machines in situations where unexpected conditions are encountered or when face pressures fail to be maintained at the design level Some attempts have been made to anticipate and prevent localized face collapse through a more systematic real ti
35. is restored Benefits Less surface occupied working area required than conventional trench method Less earth excavation volume More depth can be reached in secure conditions and without affecting the surface occupied For important depths costs are minor compared to conventional trenching Low level of operator skill required Suitable for all pipe materials In fact trench box is a modification of shoring Trench boxes are intended primarily to protect workers from cave ins meanwhile shoring is primarily used for supporting the trench face with wooden planks or metallic sheets 18 COMPUTER DED REHABILITATION OF SEWER NETWORKS v Ability to overcome unknown obstructions v In some cases other infrastructure can be rehabilitated or replaced at the same time allowing for coordination of work and sharing of costs Drawbacks x The cost of the trench box or shoring methods can be higher compared to some newer technologies x Construction be longer than conventional trenching for shoring In the case of trench box little time to settling up would be minor than for digging slopes or benchings x There are more safety concerns due to traffic issues on road rights of way the number of excavations required and the large equipment needed to perform the work x There can be disturbances to other surface and buried infrastructure x The social and economic costs of major o
36. its original dimensions once the winch tension is released and in most cases with the help of internal pressure This technique is most successful when there are long runs with few connections because of the time and cost of re opening the laterals Depending on the reductions and the reversion technique these systems can be divided in Swage line The pipe is pulled through a steel die at an elevated temperature This method doesn t allow stopping Die draw 40 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE The pipe is pulled through a steel die Ambient Diameter reduces from 6 to 10 without increasing its temperature Natural relaxation on release of tension reverts the pipe to its original size This process is only continuous can t stop Rolldown In this case the pipe is pushed through hemispherical steel rollers at ambient temperature that reduces the diameter up to a 10 The reversion process is achieved using cold pressure water This method can be discontinuous allowing stops Process A insertion pit is dug to accommodate butt fusion welding of pipes before the diameter reduction and during insertion The diameter of the PE pipe is reduced by being either pulled or pushed through the reduction devices This operation may require the use of a lubricant Winch loads are variable depending on whether liner is pulled or pushed into deforming tool Once the pipe has been introduced in the host pi
37. may be solved by operational methods rather than renovation or replacement for example certain types of sedimentation which may be handled by jetting This task will present arguments for operational options or local redesign versus renovation and replacement This task will generate report D11 Survey of operational options Structural rehabilitation Task 4 2 Rehabilitation of sewer and storm water networks includes system improvements detention basins separation of storm water etc as well as renovation technology During the last 20 years there has been an extensive development of technologies for sewer and storm water rehabilitation Today a large variety of methods exist to meet problems in small sized as well as large sized pipelines Several cities use renovation as their first priority measure against structural and hydraulic decline This task aims to analyze which measures are appropriate to meet various kinds of problems A list of measures and problems they should apply to will be presented and used for the rehabilitation manager considering their potential for pipe failure in one hand and their characteristics leading to more or less social disturbance and annoyances on the other hand Also attention will be brought to the innovative question of establishing the explicit links between the rehabilitation techniques with or without trench and the other aspects of the project calibrate disturbances to the citizens WP5
38. of annular gap ribbed external surfaces assists bonding Process changes significantly depending on machinery used static or traveling 46 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Benefits v n some case long lengths can be achieved Changes in diameter can be accommodated Slow bends can be accommodated with some techniques Installation can be carried out under flow There is minimal disruption at the surface as access can take place from existing access holes manholes lt lt S S Drawbacks x require grouting Needs trained personnel to operate winding equipment x Digging or robotic operations required for re open lateral connections Possible reduction in hydraulic capacity x Can only line circular cross sections Man entry sewers Process Liner strip fed into pipeline via existing access points Profile arranged into helix in host pipe locking strip hammered into joints Integral rubber seals can be used to produce watertight joint section plates can be used to join coils Interlocking profile edges on liner strip Self powered winding machine can travel through pipe can create non circular sections Once installed Standard cement grout is injected through drilled holes in liner Bracing may be fitted to prevent distortion Drilled holes are plugged when grouting complete Laterals are cut as the tube is installed rapid hardening mortar us
39. of the sewer Process sewer is cleaned the water canalized in small pipes or pumped and sewer length is provided with electric light detected the zones to inject be done with radar detector small drills are made Mortar is grouted through the drills sequencely to prevent voids in the injection Drills are sealed and the advance continues until the end of the damaged zone Sometimes this operation is finished up plastering the sewer internal surface auxiliary installations are taken away and the sewer is back to service Benefits v Very useful for grave or generalized fractures v Structural and sealing technique v surface damage is produced No dig required v Very low social cost as few traffic disturbances noise or dust produced v Very quick total working time compared to digging methods Drawbacks x Only suitable for man entry sewers x Possibility of environmental damage if grouting chemical material in sensitive zone x Many security and health measures to be observed x Difficult to measure in the project if voids surveying with radar has not been done C 1 2 3 5 In situ invert repair This technique is very useful for repairing collapsed inverts and consists in reconstructing the concrete or brick invert sewers In many cases the performance of the sewer is adequate except for the inverts usually the most wasted part of the sewer because of the time slope
40. pit before beginning the boring operation with the complete auger and cutting head unit placed inside the casing The entire system is then lowered into position in the bore pit via cranes Once the desired line and grade of the casing are established the boring process is performed in a continuous manner until completed Free boring where a casing is not used is also available for small diameter pipes 50 150mm where damage due to a collapsed bore will be less significant Process A helically wound auger flight contained within a steel casing is attached to a cutting head rotating action of the auger flight simultaneously rotates the cutting head which removes soil from the bore cutting head and augers are powered from the drive pit Most systems contain pipe jacking equipment which allows the casing to be moved forward as the cutter progresses casing forms a bore for the product pipe to be inserted Benefits v technology is well established and widely available v steel casing remains the bore after the drilling operation is complete it can be used as a conduit or as the host pipe v Little or no soil disruption v Little disruption to traffic Drawbacks x Steering capability is very limited after installation is initiated x Notsuitable for soil containing boulders or very soft clay organic ground x Ground investigation essential C 3 2 3 Off line replacement stee
41. ramming auger boring guided auger boring guided boring horizontal directional drilling HDD guided drilling mini HDD conventional pipe jacking low load pipe jacking thrust jacking microtunnelling minitunnelling tunnelling shield Legend suitable conditionally suitable data will be filled replacement in new line 113 The CARE S Partners NTNU A SINTEF Cemagref ENGEES UN Universita 4 3 277111717771117 Budapest University of Technology and Economics pe ZX TECHNISCHE YY PECHNOLOGY l UNIVERSITAT DRESDEN fil SINTEF Trondheim Norway NTNU Trondheim Norway CLABSA Barcelona Spain University of Ferrara Ferrara Italy Cemagref Bordeaux France Engees Strasbourg France CSIRO Australia University of Bologna Bologna Italy University of Palermo Palermo Italy Aalborg University Aalborg Danmark Technical University of Budapest Budapest Hungary Brno University of Technology Brno Czech Republic Dresden University of Technology Dresden Germany Laborat rio Nacional Engenharia Civil Lisboa Portugal WRC plc Swindon United Kingdom Partner name CLABSA Address Acer 16 08038 Barcelona Spain Contact person Carlos Montero Phone 34 93 289 68 00 E mail cmontero clabsa es Fax 34
42. re rounding sited on position pipe reversion is carried out by pressurized steam with hot or cold water or air depending on material employed PVC liners typically show some deformation into laterals which enables easy identification of lateral connections for robot opening in no man entry sewers Benefits v The site folded technique is less sensitive to the variations in diameter or pipe with dimensional irregularities when compared to the diameter reduction technique There is minimal loss of pipe diameter and no grouting requirement when compared to the traditional sliplining technique Liner can be coiled for transportation depending on diameter The improved interior friction coefficient may increase hydraulic capabilities Long lengths of structural liner can be inserted Both structural and non structural systems available depending on the condition of the host pipe Sealing technique and can also be structural Some liners can be used in host pipes with bends up to 45 with some internal wrinkling There s no need of a completely clean neither dry sewer Method can be applied even if infiltration exists It is rapid and causes little disturbance to other utilities 5 4 LN A S Drawbacks x Site or cold factory formed liners require restraining bands to hold the reduced cross section x Factory folded liners cannot be welded on site and therefore restrict the size and length of liner that
43. reaming Pipe reaming is a modified back reaming method used in directional drilling which is specially adapted for pipe replacement The reamer has cutting teeth which grind and pulverize the existing pipe through a cut and flow process rather than a compaction Process pilot drill string is inserted through the existing pipe specially designed reaming tool is attached to the drill string and pulled back through the pipe while simultaneously installing the new pipe pipe fragments and the excess material from upsizing are carried with the drilling fluid to manholes or reception pits and retrieved with a vacuum truck or slurry pump for disposal Benefits This method permits in line replacement and upsizing of sewers Reduced disturbing in paved surfaces or adjacent utilities No fragments from the old pipe are left in the ground It enables sagging sewers to be realigned Steering is possible within limits and can follow the alignment of existing pipe Cleaning of the existing pipe is not necessary 4 Drawbacks x method is not suitable for the replacement of metallic or thermoplastic pipes It can be costly in comparison with pipe bursting Laterals must be removed Drive and reception pits are required x C 3 2 1 8 Pipe crushing implosion Pipe crushing is a replacement method based on static pipe bursting In this case the old pipe is not explo
44. starting the pipe bursting or surveyed to latter robotic re opening Sometimes an external protective sleeve pipe is installed during the bursting process and the product pipe installed within this casing or conduit pipe This is normally only considered for pressure pipe installations Alternately in gravity sewer applications the wall thickness of the product pipe is increased to allow for external scaring of the pipe as it is pulled into place The general description of pipe bursting methods is done before specific characteristics for percussive pipe bursting are explained 52 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE bursting operation can proceed either continuously or in steps depending on the applied type of pipe bursting system Before bursting is convenient clean of sand or debris the pipe the required pull force will be reduced and the service connections must be located and disconnected The system then is more successful when there are long lengths to rehabilitate with few connections Variations on this process are available for different host pipe materials Typically pipe bursting is used in brittle materials cast iron clay and concrete Process cone ended bursting tool bursting head is inserted into the existing pipe and forced through it applying radial force to break open the pipe rear of the bursting head is connected to the new pipe and the front end of the bursting h
45. suitable for non circular sewers It does not provide structural repair Difficult quality control Rubber joint A variant of this technique primarily used in pressure applications is the use of internal joint seals The seal s flexibility ensures a bottle tight seal around the entire pipe joint while its low profile and graded edge allows water to flow without creating turbulence Internal joint seals are made of EPDM ethylene propylene diene monomer synthetic rubber This technique requires operatives to access the sewer to perform the work and as such pipe diameters of sufficiently large size are good candidates for this technology Process Bypass pumping is done in the affected length The pipe joints must be completely cleared of debris and dust Complete preparation of the area on either side of the joint is also required to accommodate the lip of the seal Once the cleaning is completed a Portland cement grout is used to fill the joint gap completely and made flush with the internal surface of the sewer The area must be cleaned with a dry brush and coated with a lubricant soap compatible with the type of seal being used The lubricant soap is only an aid for installing the seal The seal is then placed in position spanning the gap Stainless steel retaining bands are then installed in the grooves of each seal A hydraulic expanding device is used to apply the correct pressure to the retaining bands thereby keeping the sea
46. the ground It is an unsteered boring device There is no rigid connection between the mole and the insertion pit and the progress of the mole relies upon the frictional resistance of the ground for its overall forward movement Hence the performance of the mole is high dependent on the type and conditions of the ground Fixed and moving headed moles are available driven by pneumatics and or hydraulics It is claimed that the moving head types impart all the energy into pushing the head into the ground whereas for the fixed headed types the internal impact has to overcome friction and move the body at the same time Adaptations to standard moles are available that cope with different types of ground The hammering action can either be a simple striking of the piston onto the forward end of the unit or a two stage action of a specially designed moving head Compressed air repeatedly propels the piston against the rear of the chisel head assembly This first compresses the pre tensioned steel spring which forces the chisel head assembly forward independently of the main casing The first impact creates a pilot bore Then the same continuous force thrusts the main casing ahead The second impact expands the borehole to its final diameter Non steerable moles typically involve the excavation of two pits an insertion pit and a receiving pit After the careful alignment of the mole in the insertion pit the tool is expected to advance through the g
47. tunnel Line and grade tolerances of two centimeters are the standard This technique can be economically competitive with direct burial when depths exceed 6 meters due to the costs of deep trench excavation and trench support This method is cost effective when faced with unstable soil conditions and work below the groundwater level These conditions increase the risk of surface settlement during a direct burial or conventional tunnel installation These conditions also increase liability for all parties with regard to property damage and personal injury The increased pipe wall thickness required for jacking pipe provides a longer service life of sewers installed Manufacturing and quality control standards are higher for jacking pipes than for buried pipes Improved steering precision is achieved when a theodolite based guidance system is used instead of the traditional laser guided system This theodolite system can provide an as built location of the pipeline at every 3 cm The system can also be designed to do curved pipe jacking One weakness of FRPM Fiber Reinforced Plastic Mortar pipe is a lower jacking force capacity when compared to other pipe materials of the same internal diameter Historically larger diameter pipe and inter jack stations are used to achieve long drive lengths Inter jack stations are jacks placed inside the tunnel to provide additional jacking capacity or to provide a more even distribution of the jacking capacity
48. water air or steam or by using ultra violet lamps Typical resins systems are Vinyl ester Polyester Polyurethane and Epoxy Typical carrier felts are manufactured from Polyester possibly reinforces with glass or carbon in a variety of fibre matrix orientations e g Chopped strand or woven An elastomeric or thermoplastic PE PVC coating is normally incorporated on the felt this is the surface in contact with the liquid flowing through the pipeline There are three main groups of CIPP systems These are available independently or in combination felt based woven hose and membrane systems Felt Based Liner System This liner is made of non woven polyester felt coated on one face with a layer of elastomer The felt based liner can include reinforced fibers to provide full or semi structural integrity of the liner The resin used in this application also plays a large role in the structural integrity of the new liner The liner is normally impregnated with the resin at the factory then transported to the site for installation The transportation to the site frequently occurs in a refrigerated truck to prevent premature setting of the resin For larger diameter liners the resin is sometimes applied on site Woven Hose System These liners normally offer a semi structural system within the host pipe The liner is very thin and the successful installation depends on the quality of the adhesive bond to the host pipe wall As such the quality o
49. which is hydraulically jacked from a drive shaft Some steering of the shield is possible to ensure correct alignment however initial alignment is obtained by laying the pipes sections on guide rails prior to jacking During jacking the alignment is checked against a fixed reference point Sequential thrusting of sections of the pipeline is possible using intermediate jacking stations This enables longer lengths to be installed 68 COMPUTER DED REHABILITATION OF SEWER NETWORKS Jointing systems must be flush with the pipe wall and strong enough to withstand jacking forces Process Benefits v be used in structural applications v Sealing technique v Only pit damage done in surface pavement Pit dimension can be important in large diameters v Noise and traffic disruption less than conventional trenching Drawbacks x Excavation of the bore is carried out from the jacking shield which consists of a steel cylinder Excavation can be carried out by hand mechanical excavators or remote controlled tunneling shields The product pipe is connected to the back of the tunneling shield and further sections added as installation progresses Forward movement is achieved by hydraulic jacks in the drive shaft that react against a thrust wall in the shaft The process must be carried out continuously to avoid excessive gripping of the pipe by the surrounding soil Spoil may be removed by auger flight slurry pumping
50. www trenchlessdataservice com http www tttechnologies com http www ukstt org uk http www wef org 109 COMPUTER AI DED REHABILITATION OF c SEWER NETWORKS CARE H ANNEX 1 RTS VS DEFECTS Elaborated by BUT Brno University of Technology Jaroslav Raclavsky Vladimira Sulcova Vanda Kuzmova Jitka Mertovaby 110 COMPUTER DED REHABILITATION OF SEWER NETWORKS CARE prEN 13508 2 Conditions of drain and sewer systems outside buildings Part 2 Visual inspection coding system BA Codes relating to the fabric of the pipeline Main P inca Characterisation 1 Characterisation 2 vertical 0 0 00 yj PB 1 07 0039 _ ER Deformation Break Collapse Defective brickwork mason BAF Surface damage Intruding connection BAH Defective connection A surface crack Y ATV Advisory Note M143 Part 2 Optical Inspection Code Characterisation LB E F O U L R nn deflection D 0 U L R nn deformation of plastic pipe SRIB EF OLR fissure in cut out hole B crack T helical A B C A displaced A B break missing collapse another layer of brickwork or nothing is visible i F 2 B spalling break in away of small fragments from the surface of the fabric reinforcement projecting from surface corroded reinforcement o meos RL E F O U L R nn longitudinal fissure RQ E F O U L R c
51. 35 res 135 triage Ei Ka i EL 1 154 Tas wa 351421 re 3 5 75 337 Ane eheu peg 19 renga fabrie 6 teer ei ad pret T T3 nd hA 3336 and TANTO Ir ani SISTI 7 i pci ruled abe DEDI sas E I 300 120 4111113 du 753 EJ EJ 155 E EA AS LANSO TESTES 00 ENEJ EA E ECON rimad 444 4422 si ITE 2 Th 77 F515 71301111115 z 2 amps aoa az e a a a a a 2444441 Bet Soong Wades roc veal ring HE sang HOG pr ppa H ipa aaja 9990 a 23 2 2 tje 2 2 ja 8 H 1853 33 22 sfefetotofofofotol of cfofefofajefedel ja aja a a a s ada 2 2 a la a a 2 a a iet ossa a
52. A RESEARCH PROJECT SUPPORTED BY THE EUROPEAN COMMISSION UNDER THE FIFTH FRAMEWORK PROGRAMME AND CONTRIBUTING TO THE IMPLEMENT OF THE KEY ACTION SUSTAINABLE MANAGEMENT AND QUALITY OF WATER WITHIN THE ENERGY ENVIRONMENT AND SUSTAINABLE DEVELOPMENT EVK1 CT 2002 00106 REPORT No 4 2 April 2004 Work Package 4 Delivery D12 WASTEWATER REHABILITATION TECHNOLOGY SURVEY S CARE Carlos Montero CLABSA ngel Villanueva CLABSA Vladimira Sulcova TUB Jaroslav Raclavsky TUB Hafskjold L Sigurd SINTEF Gabrielle Freni Palermo Univ CARE S Computer Aided REhabilitation of Sewer networks COMPUTER AIDED REHABILITATION OF SEWER NETWORKS CARE Work package 4 Rehabilitation technology information system Report D12 Wastewater rehabilitation technology survey Principal authors Carlos Montero CLABSA ngel Villanueva CLABSA Jaroslav Raclavsky TUB Vladimira Sulcova TUB Hafskjold Leif Sigurd SINTEF Gabriele Freni Palermo Univ Collaborators Vanda Kuzmova TUB Jitka Mertovaby TUB Dhammika DeSilva CSIRO S COMPUTER AI DED REHABILITATION OF SEWER NETWORKS CARE COMPUTER Al DED REHABILITATION OF c SEWER NETWORKS BRIEF INDEX INTRODUCTION isis snoei oiae iis neiise asista sia isis 11 CARE S PROJECT sssssssssssssssssssssssssssssssssssssssososssosssosssesssosssosososssosssosssosssososososo 11 2 WORK PACKAGE 4 isis sessssisca
53. ATION 102 E33 DEATAINPUT tenisinin a tee Pe 102 F 3 4 104 F 3 5 COST TOOL DEFAULT DATA FILES AND CUSTOMIZATION cette 104 F 3 6 COST TOOL FILE MANAGEMENT AND COPY PASTE PROCEDURES tm 106 F 3 7 ACCESSING TO DAYW ATER 107 F 3 8 HOW TO GUIDE ccccccccccccecsssssseceeeccceceesessesececeeeceesenssaeaeeeseeeesessaaeceseeseseneeeaaes 107 G 109 ANNEX 1 RTS VS 11 110 S COMPUTER AI DED REHABILITATION OF SEWER NETWORKS CARE 10 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE A INTRODUCTION 1 CARE S project The Computer Aided REhabilitation of Sewers network CARE S project is funded by the European Community under the fifth framework program and contributing to the implementation of the key action sustainable management and quality of water This project aims to establish a rational framework for sewer network rehabilitation decision making The work plan has been divided in several Work Packages and tasks has been distributed among CARE S partners The WP s are WP1 Performance Indicators WP2 Structural condition WP3 Hydraulic capacity WP4 Rehabilitation technologies WP5 Socio economic consequences WP96 M
54. B fissure BAC break collapse BAD defective brickwork or masonry BAE missing mortar BAF surface damage BAG intruding connection BAH defective connection BAI intruding sealing material BAJ displaced joint BAK lining defect BAM weld failure BAN porous pipe BAO soil visible through defect BAP void visible through defect 90000 000 0 0 0 0 e Related to pipeline operation roots BBB attached deposits BBC settled deposits BBD ingress of soil BBE other obstacles BBF infiltration BBG exfiltration BBH vermin 900000 0 The rehabilitation technologies are referred to all these defects according if they are suitable index 2 conditionally suitable index 1 or not suitable index 0 When a RT is indexed as suitable it means that the technique is appropriate to solve the defect and it s usually employed to that aim RT is adequate and reasonable to solve the defect in a cost benefit context i e its use is not disproportionate to the defect If a RT is considered as conditionally suitable it means that the technique may be able to solve the problem under specific conditions or it s reasonable in determinate cases Depending on the seriousness of the defect the technique may be a good solution or just unsuitable For instance sliplining may be a good solution for used for breaks BAC but if breaking is large or sewer is collapsed this technique is not usable under norma
55. D Regression over installers price Cost 1 3086 diameter 8 1905 length Not checked over 500mm diameter 101 COMPUTER DED REHABILITATION OF SEWER NETWORKS CARE F 3User manual for the rehabilitation technologies DB F 3 1 General description Rehabilitation cost tool The cost tool is designed to obtain rehabilitation costs depending on the characteristics of the pipe and type of technology that has been selected The tool provides for every pipe that will be passed to it two costs that can be interpreted as the extremes of a possible cost interval or two different costs of the selected rehabilitation technology depending on specific conditions winter summer costs night day costs using end user or hired workers The cost tool is based on excel spreadsheets and macros and it is fully user definable rehab technologies cost drivers cost formulae and default values can be edited by the user This is needed because several local factors can influence both the costs and the dependencies between costs and driver factors that influence the costs This aspects will allow the user to change the structure of the tool depending on his specific needs Opening the Excel file the system asks for a password that is wp4 The password is not limiting any activity and it was defined only for avoiding accidental modifications to the spreadsheet macros Rehabilitatie x MPipe characteristics RT costs Defaylt
56. EWER NETWORKS CARE viii Searching for technologies able to work only in a defined range does not make as much sense as it may seem E g techniques that solve defects of pipes where diameter is 300 lt D lt 600mm The command would be min greater 300 amp max minor 600 In this case no technique is found The reason techniques solving problems for pipes greater than 300mm can also solve pipes greater than 600mm Tip in such cases just search for the minimum diameter min greater 300 3 After filling in your requirements you can now click on search button 4 The list of techniques matching your search criteria will appear In the top left you can see the number of techniques found Just double click over one of then to access the complete information of the technique 5 If a warning message appears instead of the list with no technique found try to search with fewer criteria masonry 1 2 3 02 Fill with mortar and plaster 1 2 3 03 pointing 1 2 3 04 injection 1 2 3 05 situ repair 1 2 3 06 pre cast repair 1 2 4 02 mortar stabilitation Technique 6 Structural Sealing 2 2 1 04 polymer lining 2 2 3 03 segmental sliplining 3 2 3 08 minitunneling 3 2 3 09 tunneling 3 2 3 10 shield 4 1 1 01 Manual cleaning Tech applicable to Sewers v Manholes Laterals 2 2 1 02 steel reinforced cement mortar spray 2 2 1 03 fibres reinforced cement mortar spray
57. R NETWORKS Benefits Y Once repaired the intrados is fulfilled with adequate material earth granulates and the surface pavement restored More adjusted and controlled working area required than trenching or shoring v Less earth excavation volume v Very far depth limit within secure conditions v For large depths costs are minor compared to conventional trenching Suitable in any kind of soil although rocky soils increase the costs and the time v Suitable for all pipe materials v Ability to overcome unknown obstructions v n some cases other infrastructure can be rehabilitated or replaced at the same time allowing for coordination of work and sharing of costs Drawbacks x Very high cost because the material employed in wall construction is not retrievable It s a bad waste if intrados has to be fulfilled after repair as structural elements walls loose their sense Construction time is longer than trenching or shoring There are more safety concerns due to traffic issues on road rights of way the number of excavations required and the large equipment needed to perform the work There can be disturbances to other surface and buried infrastructure C 1 1 2 3 Sheet pile This method consist on a row of interlocking vertical pile segments or sheets driven to form an essentially straight wall If required the sheet can be retrieved Process The process is similar than for concrete s
58. SN NN S NA XS Drawbacks Mixing of the resin may have to be carried out on site in few cases Sizes smaller than 100 mm or larger than 600 mm have greater difficulty of installation Time must be allowed for curing of the resins Heat or steam is required for some systems Obstructions can inhibit lining process Lateral connections have to be excavated or robotically re opened in no man entry sewers Partial buckling and or ovality may occur during installation For full structural applications liner preparation and installation processes must be carefully monitored to avoid long term liner problems Need for bypass pumping Medium high level of operators skill required Sewer service must be disconnected as well as high flow and laterals Control of infiltration required depending on resin used x x xx 49 COMPUTER DED REHABILITATION OF SEWER NETWORKS Set up cost are high so it s not recommended for short lengths x Pre grouting may be necessary in damaged areas or where there are voids x Safe access conditions for man entry required C 2 2 5 1 Ambient cure Benefits v Very simple installation Drawbacks x Very slow curing process forces disconnect laterals and by pass water many hours x If diameter is medium or large D gt 500mm liner walls thickness is larger and so curing process won t reach inner part of the layer x Out of use today C 2 2
59. Trenchless technology C 2 2 1 Coating lining C 2 2 1 1 Reinforced cemetitious In consist in man made plastering with special products reinforced cementitious the inside sewer surface The surface must be adequately prepared to ensure good adhesion A variety of modifications can be made to cement to modify its properties depending on desired coating effect Process sewer is cleaned and dried Connections temporarily cut Sometimes a preliminary task of demolition and extraction of damaged elements is necessary Cementitious product is applied over sewer walls After relatively short curing time sewer is back to service Benefits v adapt to different requirements chemical attack abrasion structural reinforcement sealing v Variations in cross section easily accommodated 36 COMPUTER AI DED REHABILITATION OF SEWER NETWORKS CARE v Lateral connections relatively easy to handle v surface damage is produced No dig required v Very low social cost as few traffic disturbances noise or dust produced Drawbacks x Only suitable for man entry sewers Sewer surface needs to be carefully prepared to ensure bonding Control of infiltration required Many security and health measures to be observed 2 2 1 2 Steel reinforced cement mortar spray Man made In man entry sewers lining is normally carried out using a hand spray gun The surface must be adequately prepared
60. _Values Ex amp Figure 1 buttons and spreadsheets that are available in rehabilitation cost tool Three worksheets should be visible for the user and a toolbar with five buttons Figure 1 The first worksheet Pipe characteristics is used to input pipe data according to the cost drivers that are defined by the user or by CARE S default F 3 2 Scope of application The scope of the cost tool is to provide costs or cost ranges to the other CARE S tools The tool can be run as a stand alone Excel application in order to allow the user to evaluate rehabilitation costs for single technologies or projects and inside the CARE S prototype in order to compare different rehabilitation projects on economic basis F 3 3 Data Input Basically the cost tool has been developed with the same philosophy of rehabilitation technologies database As it has been constructed in Excel it can be easily modified according to end user preferences In particular it can be updated with new techniques drivers and formulae giving the end user the possibility to adjust this tool to his experience and local specific conditions climate local salaries and construction material costs etc 102 COMPUTER DED REHABILITATION OF SEWER NETWORKS CARE Pipe data have to be copied in the spreadsheet Pipe Characteristics following the scheme defined in the headers This operation can be done manually by the user or provided autom
61. aded push fit or snap fit joints enables close fit with host pipe Joints are sealed using an O ring Plastic pipes can pre molded to specialized dimensions for non conventional shaped pipelines They are typically 2m in length and are welded prior to winching into position Benefits Quick insertion Can accommodate large radius bends Can line non circular cross sections causes little disturbance to other utilities It usually provides an improved friction coefficient for improved hydraulic performance Depending on flows installations can be done in live lines without bypass pumping Low degree of skill required LN NN A S Drawbacks Labor intensive jointing Reduction in pipe cross section may be significant May require grouting Safe access conditions for man entry required Excavation to reconnect lateral may be necessary for non man entry sizes When short pipe sections are used there is an increased cost in the jointing techniques Lateral connections have to be excavated or robotically re opened in no man entry sewers 2 2 3 3 Segmental sliplining Pipe segments are prefabricated sections specifically for man entry mains They are constructed from two pieces joined longitudinally and circumferentially and can be made from glass reinforced cement GRC glass reinforced plastic GRP plastic reinforced concrete PRC concrete or reinforced gunite Units are assembled man
62. afterward or surveyed by CCTV closed and reopened after rehabilitation x All underground structures within one meter of the existing sewer to be rehabilitated must be excavated to avoid damage that may occur due to the force being transmitted and the displacement of soil by the bursting operation x Higher cost and time operation than for other pipe bursting techniques x Over pumping required C 3 2 1 5 Pipe splitting Pipe splitting system is used for pipes that are not brittle like some plastics steel and ductile iron Instead of the bursting head the system uses a splitter which cuts the existing pipe along one line and opens it out rather than fracturing it The splitter consists on a pair of rotary slitter wheels which make the first cut a hardened sail blade on the underside of the splitter which follows and an expander whose conical shape and off centered alignment force the split pipe to expand and unwrap The unwrapping of the pipe is smooth without generating hoop stresses or longitudinal bending in the pipe walls that could cause high pulling forces and jamming The splitting and unwrapping of the existing pipe creates a hole immediately behind the splitter large enough to allow the new pipe to be pulled in The old pipe dislocates to a position above the hole and the replacement pipe thus protecting the new pipe from damage Process splitter is inserted into the existing pipe and pulled through it by eit
63. ame technique might provide different lifetimes for the sewers and that some techniques are difficult to compare it has been decided to leave this field in blank so the end user is able to assess this value based on his local experience 89 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE D 2 3 Environmental impact Environmental characteristics are assessed providing additional information for indirect costs calculation Next characteristics are measured in a very basic scale and it s not necessary to say that different local conditions manufacturers and installers may cause greater or lower impacts D 2 3 1 Structural impact on the surrounding buildings or networks In densely built areas as most of European city centers are the underground is occupied by many urban services and most times urban networks run in parallel and cross each other along the streets Digging a trench or using a soil aggressive technique techniques that make heavy vibrations in the ground and or compact the soil can damage the infrastructures nearby including the foundations of the buildings D 2 3 2 Environmental impact of materials and Works Basic and general assessment of the environmental impact caused directly by the works including the materials employed Techniques are classified as none low mid or grave impact and its combinations D 2 3 3 Impact on groundwater quality It becomes essential to know if the rehabilitation technol
64. and for man entry constructions by skip trucks and conveyers Auger flight is preferred for short drives and slurry pumping for long drives especially in the presence of groundwater Thrust plates or blocks in the insertion pit are required Thorough site investigation required Soil characteristics determine pipe material High level of operator skill C 3 2 3 5 Low load pipe jacking A pipe jacking method variant in which separate provision is made to carry the jacking load the pipe being installed carrying little or none of the jacking force C 3 2 3 6 Thrust jacking Pipe jacking method variant in which a pipe is jacked through the ground without mechanical excavation of material from the front of the pipeline 69 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE C 3 2 3 7 Microtunneling A technique for installing non man entry pipelines using a steerable remote control pipe jacking technique Micro tunneling is different than full tunneling in that the process uses a remotely controlled boring machine combined with the pipe jacking technique to install pipelines directly Microtunneling is a process that uses a remotely controlled Microtunnel Boring Machine MTBM combined with the pipe jacking technique to directly install product pipelines underground in a single pass from 300mm to 3600mm in diameter Microtunneling has evolved to describe a tunneling process where the workforce does not routinely work in the
65. andslide and consequently risk for operators 1 1 2 Semi open cut C 1 1 2 1 Shoring and Trench box modificated shoring Trench box and conventional shoring are presented together Trench box is a digging method that consists on the excavation of a trench and the protection of it by means of a couple of pre cast parallel metallic sheets separated by means of shores This allows trenching in non cohesive soils and digging more deep keeping the security conditions and saving sloping and benching This method is also used for renovation and renewal later described Process The process is almost the same than for conventional trenching Removal of existing pavement with manual and mechanic means Transport of resulting products to a rubbish dump Trench excavation using mechanical digging or hand digging if other urban services could be damaged The trench is normally wide enough for operative to carry out repair works trench wall is shored up to prevent risk of collapse or the trench box is located De watering may also be required under watertable layer of bedding material is laid along the bottom of the trench and the pipe laid on top Once the pipes are assembled and lateral connections made the protections are moved away Then the trench is back filled and compacted in layers if granulate material employed or with concrete to ensure adequate support around the pipe Finally the surface pavement
66. are produced to nearby buildings and infrastructures Construction time is much shorter than for concrete sheet piling Not suitable for medium hard rocky soils There are safety concerns due to traffic issues on road rights of way the number of excavations required and the large equipment needed to perform the work There can be disturbances to other surface and buried infrastructure C 1 2 Trenchless technology C 1 2 1 Robotic repairs C 1 2 1 1 Injection in joints or cracks Robotic options are larger each day Specialized companies create and innovate new products specifically designed for sewers Most of them consist on a CCTV equipment self propelled in many cases with interchangeable repair devices Injection robots are able to grout mortar or polymers in the sewer Process CCTV sewer inspection detects the defect joint crack or fracture giving its precise location and dimensions In some cases sewer has to be cleaned allow the access to robots In many cases the operation has to be done without running water and so it s necessary to cut the connections and water pumping 21 COMPUTER DED REHABILITATION OF SEWER NETWORKS CARE The robot is assembled with the proper devices for injection and introduced in the sewer trough the manhole The defective reparation is guided with the aid of a CCTV It can be set in the same or in different robot depending on robot performances Rob
67. atically by CARE S Rehab manager Data can have blank spaces for example when data about some pipe characteristics are missing In those cases the tool will use default values that are contained in the Default Values spreadsheet Figure 3 H Te p eee H PEETI i TE Aum W rdi Ee 2 mz s B Nj 4 ammasm rapa HEADERS PRE Tech Prepeweo Prepews gu D Lu reni prd ww pn PIPE DATA i3 16 Cy Se 2 15 KI Lr menm Gardan qa 15 5 FI Tam Tam Ho e dad fuu ren E Fem EL i mem s a a ui mata 0 zz n a pL ee DTI Figure 2 Pipe characteristics spreadsheet In the second row this spreadsheet counts automatically the number of pipes that are entered This is essential for the definition of the RT_costs spreadsheet because fixes the number of times the tool has to be run in order to obtain the rehab costs The Default Values spreadsheet contains the cost driver values that the tool will use in case pipe data are missing the specific information The user can modify the defa
68. bances noise or dust produced v Useful for deep sewer under the avobe described construction conditions Drawbacks x Only suitable for man entry sewers x Walls or vault dissembling requires shoring so sewer must be disconnected of the network to avoid water pulling shoring structures during rainfall events x Difficult to measure in the project if voids surveying with radar has not been done x Many security and health measures to be observed x To complete sewer repair other techniques like fissure sealing are required C 1 2 4 6 Surrounding stabilization This technique consists on soil stabilization by means of grouting usually with mortar slurry Its used as curative as well as a preventive method when constructing big buried infrastructures like train tunnels or trunk sewers This is an indirect repair technique because it hardens and toughens the soil but does not act directly to sewer It s suitable for sewers constructed in unstable or unsound soils In some cases can be used as well as a kind of protection for building foundation during tunneling construction 34 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Process Once the treatment soil area is defined a cluster of pit location is defined Injections will be done from these holes so they must be carefully distributed in the affected area In the particular case of sewers shafts should be distributed along sewer length and in both sides of
69. bor intensive technology and so cost increases x Requires grouting x There is a loss of cross sectional diameter in the existing pipe due to the installation of the panels or sections and the grouting space required 2 2 4 Spirally wound lining C 2 2 4 1 Spiral lining A ribbed plastic strip is spirally or helically wound to form a continuous plastic liner which is held in position by either grouting or expansion of the liner Can be manually wound in man entry sewers Non man entry sewers Process with a static winding machine Hydraulic winding machine positioned at bottom of manhole Profiled strip containing is fed into winding machine to form a tube Tube travels down host pipes as further turns of the helix are added Large friction build up as pipe rotates limits length of installation Grouting of annular gap ribbed external surface assists bonding Adaptations to the technique Specially designed profiled strip fed into machine Locking wire prevents joints between adjacent turns from slipping Once installed locking wire pulled to allow joints to slip helix increases in diameter Produces a close fit spiral wound liner eliminating need for grouting Process with a traveling winding machine A winding machine that travels down the host pipe as tube is created Non circular shapes can be formed using a winding cage Steel reinforcements be used for large diameters Grouting
70. broken into pieces and removed Forward movement is achieved by hydraulic jacks in the drive shaft that react against a thrust wall in the shaft 59 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Spoil be removed by auger flight slurry pumping and for man entry constructions by skip trucks and conveyers Auger flight is preferred for short drives and slurry pumping for long drives especially in the presence of groundwater Benefits v Can be used in structural applications v Sealing technique v Only pit damage done in surface pavement Pit dimension can be important in large diameters v fragments from the old pipe are left in the ground v Noise and traffic disruption less than conventional trenching Drawbacks x Pipes with significant structural damages are not adequate for this method because pipes must have enough remaining thrust capacity to withstand the push forces x Thorough site investigation required x High level of operator skill C 3 2 1 10 extraction modified static pull Pipe extraction modified static pull is pipe replacement systems in which the unbroken existing pipe is removed from the ground while the new pipe is simultaneously installed In pipe extraction the replacement pipe is pulled in place of the old pipe An extraction machine is placed into one pit and the replacement pipe is fed from the other The tool assembly consists of a centralizing dev
71. bserved Many powerman required that can increase the cost 26 COMPUTER DED REHABILITATION OF SEWER NETWORKS CARE C 1 2 3 2 Fill with mortar and plaster Brick or masonry works have a roughness surface so sometimes these surfaces are finished up with a coat of mortar of 0 5cm thick aprox that reduces the roughness of the sewer increasing its capacity and making difficult the placement of sediment deposits Depending on material mixture proportion less sand and more cement and bricklayer s work the finished surface can be very smooth This can be a good complementary action after masonry work repair is finished This technique is also used in concrete reinforced or not sewers Process sewer is cleaned the water canalized in small pipes or pumped and sewer length is provided with electric light Usually a preliminary task of demolition of damaged elements is necessary The operative fills with mortar and plaster the sewer surface auxiliary installations are taken away The sewer is back to service Benefits v Very adaptable method Material is employed only where needed Sealing method v Quite simple and cheap devices and materials employed v surface damage is produced No dig required v Very low social cost as few traffic disturbances noise or dust produced Drawbacks x Only suitable for man entry sewers Non structural method Many security and health m
72. ccscesescccccccscseees 92 2 USER MANUAL FOR THE REHABILITATION TECHNOLOGIES DB 94 COST FORMULA 11 98 F 1 REHABILITATION TECHNOLOGIES COST ASSESSMENT 98 1 2 COST FORMULA CALCULATION eeeesesesesese sese se sese sensns sensns sensns sese 98 USER MANUAL FOR THE REHABILITATION TECHNOLOGIES DB 102 G EPA E EH UEM 109 S COMPUTER AI DED REHABILITATION OF SEWER NETWORKS CARE COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE EXTENDED INDEX A 11 CARES PROJECT sscensiscisacvctescasasancceacenansacceuncdansceuoianscnascatssuaisadsannivencosaiiasocbescaacaas 11 A 2 PE ERE RD A EO PER HEREIN EFC RE REPE Don 11 OPERATIONAL OPTIONS TASK 12 STRUCTURAL REHABILITATION TASK 4 2 22 1 0 1 4200000020 0000000005000041 12 A3 11115 DOCDMEN Does 12 B OBJECTIVES Ce uan 13 BI REPORT D12 OBJECTIVES iioi 13 B 2 PROCESS AND METHODOLOGY ssesessossesocsossosoossesossossesocsossesocssesossossesocsosseseossssossos 14 B 3 REHABILITATION TECHNIQUES
73. cidents pile up and fatal in most events prove that sewer networks are a high risk asset Safety and health must be then the first priority in rehabilitation works Safety should be considered from the very first instance that is in the planning and projecting tasks This aspect has been included in the chart and database that provide information whether the technique requires operatives working inside the sewer It should be advised that trench technologies have been also considered as man in underground because its linked high risk in spite of the protections shoring sheet piles that can reduce it Tasks developed in short periods of time in manholes or access pits have not been considered as high risk activities and consequently the database of rehabilitation technologies says that these doesn t require man in underground even that partially they do D 2 2 11 Curvature allowed Sewer network is usually projected as straight lines or with small curvatures trying to disturb the hydraulic flow the less the best But city plot other infrastructures defective construction or bad design cause that the real network present turns If these changes of direction are done in manholes maintenance and rehabilitation operations are easier to be done Some rehabilitation technologies are quite flexible to sharp changes of direction like trenching or grouting Others are able to cope with small curvatures although these turns be not acc
74. d suitable for no man entry sewers robot made and in man entry sewers man made Some gunite robots are prepared for intermediate size of sections e g D 800mm in which robot operator is transported by gunniting machine in a near horizontal position 37 COMPUTER AI DED REHABILITATION OF SEWER NETWORKS CARE Robot made In this method cement mortar is applied to the pipe wall by the rotating head of a machine Process The sewer is cleaned and dried Connections temporarily cut mortar is usually pumped through hoses to the lining machine as it is being applied initial coat of cement mortar is projected Then a wire mesh that runs the complete length of the sewer is installed A second coat of cement mortar is then added After the mortar cures approximately 24 hours service is reestablished Benefits v Semistructural and non structural applications v Sealing technique v Variations in cross section easily accommodated v Most cement mortar lining equipment can accommodate small bends less than 22 59 and depending on the diameter of the water main being lined larger bends up to 45 can be accommodated v surface damage is produced No dig required v Very low social cost as few traffic disturbances noise or dust produced v Fast installation times Drawbacks x The semi structural cement mortar application requires access by workers to install the wire mesh and therefore i
75. d to create an initial hole at the required line and grade Successive reamers are then pulled back to enlarge the hole diameter to the desired size During the last stage of the reaming the service pipe is pulled back into the bore Most sewer force mains installed by this method are continuously welded PE pipe although steel ductile iron and PVC have also been used Gravity sewer installations are also possible Process rotating steerable hollow drill of 80 140mm is launched from the surface at an angle of 8 15 to drill a pilot hole under the obstacle A fluid jet cutter or mud driven cutter is used depending on soil type washover pipe of approximately 140mm diameter is drilled over the pilot string and follows behind the drill head Alternate drilling in the pilot string and the washover pipe until the exit point is reached pilot string is retracted and the bore enlarged by a rotating barrel reamer attached to and pulled back by the washover pipe Subsequent reaming until the required diameter is achieved new pipe is assembled and tested above ground t is attached to the reaming head via a swivel joint and pulled though the newly created cavity at the same time as final reaming using the pullback capacity of the drilling rig A survey pack can be located behind the cutting head ensures that an accurate path is maintained Benefits v Rapid installations v Long distances with relat
76. ded out but imploded in In the implosion system the bursting tool consists of 13 For horizontal directional drilling see 3 2 3 2 58 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE two parts a crushing head which breaks the existing pipe and forces the pipe fragments inwards into the pipe void and a steel cone which pushes the crushed pipe fragments and soil outwards making room for the new pipe The crushing head is cylinder shaped and slightly larger than the existing pipe Inside the cylinder there are steel blades which extend radially from the center and fracture the old pipe as the head is pulled forward Process bursting tool is inserted into the existing pipe and forced through it crushing head and the new pipe are launched from the insertion pit pulling is done with a rod assembly as in the static pull system that is pulled from the pulling or reception pit Pipe fragments are pushed outwards through the cone At the same time the new pipe is pulled in the annulus left by the crushing operation Benefits v Cleaning of the existing pipe is not necessary v No fragments from the old pipe are left in the ground v A larger diameter pipe be inserted Pipe capacity can be maintained or increased v It provides for full structural rehabilitation Drawbacks x The method is not suitable for the replacement of metallic or thermoplastic pipes Pit excavation
77. derstood only in that sense D 2 2 2 Performance of the technology The performance of the rehabilitation technologies is the average length of rehabilitated conduit per day This value has been estimated from diverse sources and includes the standard auxiliary works required by rehabilitation For example the performance of a trenching method includes the time for digging lying the pipe backfilling and compacting This characteristic does not include the time required for any special operation before or after the works themselves like pavement demolition or reinstatement scaffold of other infrastructures or auxiliary constructions or operations not directly linked to the installation works In the case of conduits that require latter reopening of lateral connections see D 2 2 8 this work is not included in the rehabilitation technology itself and shall be calculated separately The performance has been calculated as an average consequently particular works or installers may increase or decrease significantly this time depending on their skill or technical improvements to be more competitive but strongest variations may come from factors external 85 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE to the rehabilitation technology like working time restrictions due to traffic cut off breakdowns pace of materials supply and a wide variety of unexpected problems For simplicity reasons this value has been calculated
78. does not intend to describe with detail the steps to follow This task would exceed the intention of this document and would carry some problems as the same RT may present slight differences among different contractors installers or work conditions A short list with some remarkable benefits and drawbacks of each technique is also presented giving additional information and warning of possible problems during the works gt Apart of this basic information for the RTs Part D presents the RTs Chart In this chart it can be found the complete list of RTs together with a series of columns that contains their characteristics This is an easy way to have a general view of the RTs in particular this chart shows clearly the different categories in which the repair renovation and replacement techniques have been divided Even more a color coding system allows to identify the suitable techniques for more common defects in just a glance gt A list of over 70 RTs having each one of them more than 60 characteristics sums up around 4500 data To be able to manage them it becomes essential to store them in a Data Base structure In this sense a rehabilitation technologies data base RTsDB has been implemented with some extra features as an aided searching This RTsDB will become part of the CARE S Rehab Manager but can be also used as a stand alone DB RTs can be searched for some of their characteristics applicability conditions Its convenient
79. e Load button is used to load the formulae collected in the selected file into the present file The Save button is used to save the formulae collected in the present file to the selected one F 3 7 Accessing to DAYWATER database The last button on the right part of the toolbar displaying a daisy and some buildings gives access to the DAYWATER database of BMP costs This option has been provided through an agreement between CARE S and DAYWATER project in order to give to the user a wider range of urban drainage management options F 3 8 How to guide Next a step by step guide is presented with the functions developed in the data base and available in the menu Computing rehabilitation costs 6 If used as a stand alone tool copy pipe information in the Pipe Characteristics spreadsheet If used inside the Rehab Manager verify that information has been correctly copied in the Pipe Characteristics spreadsheet Blank spaces define unavailable information The cost tool works even if some information is missing 7 Verify default values in default values spreadsheet because they will used in case the specific information about the pipe is missing 8 Click on the Computation button the first button on the left of the toolbar displaying a calculator 9 results are provided in the RT costs spreadsheet Modifying cost drivers and formulae 3 Click on Editor button in the toolbar the second from the left dis
80. e access of the robots n many cases the operation has to be done without running water and so it s necessary to cut the connections and water pumping robot is assembled with the proper devices for pointing and introduced in the sewer trough the manhole defective reparation is guided with the aid of a CCTV It can be set in the same or in different robot repaired the robot s are pulled out and the service restored Benefits v surface damage is produced No dig required v Very low social cost as few traffic disturbances noise or dust produced v Relatively quick total working time compared with digging methods v Nodeep limit and achieves longitudes of sewer up to 100m from one single manhole Drawbacks If large surfaces require pointing the process became very slow High level of operator skill required Very specific machinery employed robots Low operations performance Pointing method be robotic or man made explained later 23 COMPUTER DED REHABILITATION OF SEWER NETWORKS CARE C 1 2 1 5 Rerounding Re rounding is intended to re shape a deformed sewers and restoring circular cross section An expander unit is used to re round the pipe and install a metal or plastic clip which holds the pipe fragments in position This technique is generally used prior to patch repair or relining Two main techniques exist both relying on an expand
81. e available of the technique Many technologies have been adapted to minor sizes A brief list of specific techniques for lateral pipes restoration is presented These techniques are explained in their respective section Lateral pipes rehabilitation technologies Dig technologies see 1 1 x x Cured in place pipe soft reversion lining see 2 2 5 x Folded liners fold and form pipe see 2 2 2 2 Swaged liners deformed and reformed pipe see 2 2 2 1 Pipe bursting hydraulic pneumatic see 3 2 1 1 3 Pipe splitting see 3 2 1 5 Pipe pulling see 3 2 1 11 Coatings see 2 2 1 x Fill and drain systems see 1 2 4 1 77 S COMPUTER AI DED REHABILITATION OF SEWER NETWORKS CARE 78 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE D REHABILITATION TECHNIQUES CHART D 1 RT Chart description As it was explained before the chart began with a list of RTs separated according European Standard EN 752 5 Several subdivisions were quickly made amongst it s remarkable the category dig or trenchless that rapports core information of the method Together with this another list of valuable characteristics for RTs was elaborated with the cooperation of WP4 partners For each characteristic the output information is presented in ranges y n high medium low codes or similar With these elements the chart was constructed putting the RTs in rows and the characteristics in col
82. e helping defect codes list box 93 COMPUTER DED REHABILITATION OF SEWER NETWORKS CARE E 2 User manual for the rehabilitation technologies DB E 2 1 General description The Rehabilitation amp Operational Technologies database The overall target of the CARE S project is to help to rehabilitate the right sewer at the right time with the right technology This MEN requires among other things access to information about available techniques and their main characteristics This EEGEN information must be available in an organized and arranged way on making it possible to perform queries Data should also be D dynamic easy to edit as technology is constantly developing The Rehabilitation and Operational Technologies database ROTs DB including information about operational methods was constructed List to serve this purpose The database is fairly simple to use especially with the help menu A useful feature to search for techniques is available from the specifically designed search engine The list facility offers quick PRIN access to each rehabilitation technology The print and edit IFzi3 features have also been developed to improve the ease of use of 3 the database for users unfamiliar with MS Access gt E 2 2 Scope of application The tool was created for two main purposes e To use as a Stand alone tool for access to information
83. e may initially be filled with grout to improve steering performance of the shield machine The pipe fragments can be removed by either vacuum excavation or by slurry pumping The system has a cutting head and a shield section The cutting head has cutting teeth and rollers that cut the pipe and cutting arrangements close to the edge of the shield that cut the ground to the required diameter to take the new pipe The cutting head is cone shaped which puts the material of the old pipe into tension and thus reduces the heavy wear of cutting teeth The shield section carries the cutting head and its hydraulic motor system The head and shield are launched from a drive pit where a thrust frame is located It provides a thrust that is applied on the cutting head through the new pipe to push the head and shield forward through the ground The existing defective pipeline is crushed and removed through the new pipeline by the circulating slurry system The new pipe may follow the line of the old pipe on the entire length or may cross the elevation of the old pipe on a limited segment only The system is remotely controlled and guided with a surveyed laser line from the drive pit and prepared to eat whatever is in the way the old pipe or the ground only For equipment that uses slurry spoil disposal the shield has a packer which projects ahead of the shield and seals off the section to enable slurry pressure to be maintained In these syste
84. e reinforced cement GRC grey cast iron 10 ductile cast iron 11 steel 12 stainless steel 13 plastic 14 polyvinylchlorid PVC 15 polyethylene PE 16 epoxy resin 17 polyester resin 18 polyester felt 19 glass reinforced plastic GRP 20 glass fibre 21 polymer concrete PRC 22 basalte 23 polypropilene PP 24 any 25 no new pipe D 2 1 6 Structural or sealing technique Most but not all rehabilitations technologies are designed to be watertight and this is one of the main characteristics of any flow conduit that avoids infiltration and exfiltration The other major characteristic of a conduit and of any structure is that it must be able to support the design loads i e it must be structurally resistant 82 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE This field of the chart gives this important information where techniques are characterized as if they are able to increase significantly the structural strength of the conduit and also if the technique avoids infiltration exfiltration exudation and other undesirable phenomena of fluid transfercence D 2 1 7 Diameter or cross section after rehabilitation One of the reasons that lead to the rehabilitation of a sewer may be a poor hydraulic capacity In other occasions the hydraulic performance needs to be improved due to different reasons That s because it s important to know the change in the cross section of the sewe
85. ead The process benefits and drawbacks are the same than for impact moling pneumatic hammer adding next Benefits v Produces less vibrations and so less disturbance to other utilities nearby C 3 2 2 4 Steerable moling Steerable moles is an impact moling technique in which the tracking head mole can be drove Process The general process for steerable moles is the same than for impact moling pneumatic hammer The operation requires a two man crew the tracker operator and the mole operator 63 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE A walkover tracking system is used as in directional drilling industry where one operator walks the bore route with a walkover locator device and monitors the progress of the tool in the ground The information provided to them by the tracking system is the tool head position depth pitch and roll Pitch is the inclination of the mole expressed in percentage of slope Roll is the rotational position of the mole nose commonly referred to as a clock face The 12 hour clock configuration is the basis for steering up is 12 o clock down is 6 left is 9 and right is 3 It is recommended that the tracking operator marks the bore path on the ground with flags or spray paint The most important task for the tracker operator is to detect horizontal deviation from the planned bore and to communicate this information to the operator of the mole Although tracker can monitor ve
86. ead to either a winching cable or a pulling rod assembly bursting head and the new pipe are launched from the insertion pit burster is powered of by pneumatics hydraulics or by a pulling rod 11 cable or rod assembly is pulled from the pulling or reception pit Pipe fragments are pushed into surrounding soil At the same time the new pipe is pulled in the annulus left by the expanding operation Benefits v Cleaning of the existing pipe is not necessary but recommended v Existing manholes can be used as launch pits v A larger diameter pipe can be inserted This in conjunction with the improved interior friction coefficient can substantially increase the hydraulic capabilities of the new sewer v It provides full structural rehabilitation v Continuous pipe HDPE or discrete joined pipe such PVC can be used v Progress rates are greater than open cut Drawbacks x Pitexcavations are normally required to accommodate the replacement of pipe sections x Ground surface heaving can occur if the depth of cover is too little or soil is un compacted x All sewer services must be excavated before bursting and reconnected to the new sewer afterward x Any rigid obstructions in the host pipe bedding will deflect the new pipe This method is not recommended where grade is critical x Over pumping required Pneumatic Pipe Bursting Pneumatic pipe bursting is the most frequently used type of pipe burstin
87. easures to be observed Many powerman required that can increase the cost x 1 2 3 3 Pointing As explained above pointing is a method of repairing a brick sewer manhole by the application of cement mortar where loss has occurred Only can be done hand made in man entry sewers Process sewer is cleaned the water canalized in small pipes or pumped and sewer length is provided with electric light Defective mortar between bricks is removed Cement mortar is applied where mortar is missing or quitted gaps between bricks auxiliary installations are taken away sewer is back to service Benefits v Very adaptable method Material is employed only where needed v Sealing method 27 COMPUTER AI DED REHABILITATION OF SEWER NETWORKS CARE Enhances sewer structural performance but difficult to measure Quite simple and cheap devices and materials employed No surface damage is produced No dig required Very low social cost as few traffic disturbances noise or dust produced 4 lt lt Drawbacks Only suitable for man entry sewers Many security and health measures to be observed Many powerman required that can increase the cost Not structural method but semi structural x x x x C 1 2 3 4 Injection Man entry sewers allow hand made injections that consist in grouting with mortar or other gel material the voids existing in the extrados
88. ection and negotiate bends v surface damage is produced No dig required Very low social cost as few traffic disturbances noise or dust produced v Relatively quick installation lt lt Drawbacks x Non structural rehabilitation method x Requires careful control of mixing speed of application x Curing times can be significant x Acompletely clean and dry water main is required x Control of infiltration is required to prevent pre cure lining disbandment or collapse x Access to customer homes and businesses is required to isolate every water service line before the lining process begins C 2 2 2 Close fit linings Close fit sliplining involves inserting a thermoplastic tube that has been temporarily deformed to allow sufficient clearance for insertion into the host pipe The tube is subsequently returned to its original shape and diameter providing a close fit in the host pipe The outside diameter of the tube is the same or slightly larger than the inside diameter of the host pipe These are normally structural liners manufactured from PE C 2 2 2 1 Swaged liners swageling Installation is achieved by concentrically reducing the diameter of the liner and then reverting to its original shape after installation The tube is passed through a set of dies referred to as swageling or through an array of compression rollers to reduce the tube diameter to allow for insertion by winching The tube then reverts to
89. ed to create seal Adaptations to techniques Steel reinforcements to increase strength of tube Outting profiles to accommodate size changes then seal with H section jointing plates and solvent adhesive Benefits v need for over pumping v accommodate laterals v line non circular cross sections v There is minimal disruption at the surface as access can take place from existing access holes manholes Drawbacks x Requires grouting x Reduction in pipe cross section may be significant x Safe access conditions for man entry required 47 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE 2 2 5 Cured in place lining CIPP or soft reversion lining CIPP is frequently referred to as in situ relining A fabric tube is impregnated with a thermosetting or ambient curing polyester or epoxy resin before being inserted into the host pipe The resin is then cured to produce a rigid pipe within the host pipe The combination of the fabric material with or without fibers and the resin can be designed to produce a new pipe that has full structural capabilities or semi structural capabilities Systems are generally supplied as an absorbent carrier felt which is impregnated with the resin matrix a reinforcing layer is also incorporated depending on the particular system Curing of the resin system is determined by the choice of resin system but may be achieved at ambient or elevated temperature using
90. ed with the aid of a CCTV It can be set in the same or in different robot Once repaired the robot s are pulled out and the service restored Benefits v NN SN S Very useful for obstructions root cutting concrete deposits and protruding laterals No surface damage is produced No dig required Very low social cost as few traffic disturbances noise or dust produced Relatively quick total working time compared with digging methods No deep limit and achieves longitudes of sewer up to 100m from one single manhole 22 COMPUTER DED REHABILITATION OF SEWER NETWORKS CARE Drawbacks x High level of operator skill required Very specific machinery employed robots Low operations performance Limited engine power x x x C 1 2 1 3 Root cutting robot The root cutting is a particular case of milling robot with specific tool The process benefits and drawbacks are the same than for milling robot See 1 2 1 2 C 1 2 1 4 Pointing Pointing is a method of repairing a brick sewer or manhole by the application of cement mortar where loss has occurred Another member of the sewer repair robots is the pointing robot This device allows the robot to raking out the old mortar and then pressure pointing Process Its the same than for injection CCTV sewer inspection detects the defect mortar missing in brick sewer giving its precise location and dimensions In some cases sewer has to be cleaned allow th
91. ements The growing importance of trenchless methods is indisputable Its advantage is more in the side of social cost reduction thanks to the absence or drastical recuction of the space occupied by works particularly in earth works This figure expresses the excavation activities during the works described by means of three parameters surveyed for each rehabilitation technology o Surface works that include any kind of pavement demolition excavation etc that affect the surface ground Techniques that operate usually from the manholes service entries don t cause surface works in this sense o Access pit rehabilitation technologies that require the digging of a restrained size hole in the ground affecting the surface locally Includes the requirement of enlarging manholes for the installation of the new pipe or works achievement In some cases two pits are required one for each end of the pipe Pit size depends on technique diameter and depth This operation is access a usual for pipejacking and sliplinning techniques o Dig or trench general excavation required decentralized along the pipeline trenching or affecting large areas D 2 2 6 Need of previous cleaning One of the usual operations done before rehabilitation works is the sewer cleaning This is also done prior to inspection and characterization of conduit defects specifically in small no man entry sewers where visual inspection can only be done with CCTV robots
92. epairing leaky joints by injecting them with resin or grout with the help of a packer to prevent infiltration or exfiltration There are numerous variations in packer design and 5 In the rehabilitation techniques context we refer to mortar stabilization when grouting is made from the inside of the sewer If mortar injection is done from the outside then we speak of surrounding stabilization see 1 2 4 6 Joint sealing includes two different techniques injection sealing and rubber joint 31 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE sophistication and most systems use either a two part acrylic gel or a water reactive polyurethane resin Process A packer with inflatable end elements is winched into position over the defective joint The packer is inflated to form an isolated annulus around the defect Air or water pressure is applied to the center section of the packer and the rate of pressure loss through the joint is measured If the loss exceeds a specified limit a grout gel or resin is pumped from the packer into the annulus and the joint is re tested Curing of the resin takes place with the packer in position Packer is deflated and removed Benefits v check for leakage prior to injection of sealant v Mobile Equipment v surface damage is produced No dig required v Very low social cost as few traffic disturbances noise or dust produced Drawbacks x x x Not
93. er to push the deformed sewer section back into shape Process using scrolled clips A stainless steel sheet or PVC clip is wrapped around an expander assembly is inserted into position the sewer Expansion to the required diameter is carried out clip is left in position and the expander retracted The clip is not considered a complete repair therefore a localized or manhole to manhole lining is normally applied after re rounding Process using segmental re rounders Consists of a short length of PVC pipe made from six hinged segments Assembly is collapsed to enable insertion into position into pipeline in position expansion is carried out using hydraulic jacks Interlocking grooves the longitudinal edges provide added strength Polyethylene foam gasket on outer surface avoids grouting into place Benefits v Stainless steel or rubber couplings can also be expanded manually into position over leaking joints in man entry sewers Segmental re rounders can be used for clay or concrete host pipes of diameter from 600 to 2800mm Can renovate entire length after re rounding defective sections No surface damage is produced No dig required Very low social cost as few traffic disturbances noise or dust produced Quick total working time lt S Drawbacks x Only suitable for circular sewers Some systems do not form a leak proof repair High level of ope
94. essible manholes like linings and steered techniques But several technologies are only able to construct straight pipelines and this must be considered when studying the convenience of a technique to solve a rehabilitation case It becomes necessary to remark that the degree of curvature allowed depends on the diameter gap of the new pipe regarding the old one If this ring gap is large the degree of curvature can be increased The database provides basic information of this aspect pointing techniques that allow small degrees of curvature during the works and those that are only valid to construct straight pipelines D 2 2 12 Night works This characteristic is an important issue in order to assess the social cost of rehabilitation works The reason is obvious during the night the traffic disturbance caused by lanes closing streets closed etc is lower and so it is the indirect costs Then rehabilitation technologies are classified as night technology when it is possible to develop the works in night periods remaining the surface with no significant disturbances during the day D 2 2 13 Estimated lifetime of rehabilitated pipe Sewers lifetime is difficult to asses because installation working conditions soil pressure frequency and many other factors make a noticeable influence in this lifetime Statistical studies are then hard and by the moment not very much reliable Considering also that different installers for the s
95. evelopment of trenchless technologies Some of the today available technologies have been developed as adaptations of larger machinery In this sense some trenchless technologies have token profit from the important advances and experiences in tunnel diggers tunnelings shields TMBs Tunel Boring Machines EPBs Earth Pressure Balance and mixed shields Ideas and adaptation of these equipment have made possible the implementation and establishment of new techniques Other techniques have developed specifically for pipe installing as consequence of urban services managers demand operators of sewers but also of water electricity gas communications etc Growth of cities that increase their paved urban surface day by day have make that technical development have inclined significantly for trenchless technologies mainly because of their lower social cost The wide range of technologies that is presented in this document leave in urban network managers hands updated information about the state of the art in pipes rehabilitation that is presumed to be enough to give managers a suitable technical solution for most of the rehabilitation problems he could face Nevertheless still there are some technical lakes to solve a few specific problems One of the most worrying problem is the lake of a low cost technique for laterals re opening in no man entry sewers We presume that next years will bring network rehabilitation responsible new techni
96. f the cleaning done on the host pipe before insertion of the liner is of prime importance Membrane System This liner system is inserted into the host pipe with an elastomeric membrane coated with resin This system is suitable for non structural sewer rehabilitation applications and is primarily used to offer internal corrosion protection It can bridge very small pinholes and joint gaps Process First step is making a CCTV inspection in the host pipe clean and if adherence with old sewer is wanted dry it If mechanical capabilities of new liner are strength enough there s no need to force adherence Then two main techniques exist for installation of the liner inversion and winch installation Inversion n some cases a pre liner is winched into position to contain the inverted liner 48 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE The end of the liner is clamped around a inversion ring and the liner is turned inside out inverted down the length of the pipe using air or water Pressure applied to the inside of the pipe after lining forces the liner to hold its shape of the host pipe while the resin system under goes its specified cure regime Winch Installation collapsed liner is pulled through the length of the pipe and inflated for example using compressed air and cured for example using steam Some liners have resin sandwiched between 2 plastic membranes to prevent the resin coming
97. for usual pipe sections Large sections diameters may require more time to be installed and small ones can usually be placed quicker In general this simplification should be good enough for the purposes of use of this characteristic that is to provide an idea of the duration of works for social cost assessment In favorable conditions daily peaks of performance are expected to be higher than average values presented In some cases particularly in repair methods the values are more difficult to assess as rehabilitated length depends also of the actual state of degradation of the sewer itself and not only of the technique Also few techniques are not measurable in length of conduit per day m d because its own characteristic e g slurry injection or because the performance varies remarkably with the size of the sewer section or diameter e g masonry works or concrete sheet pile In these cases performance is given in appropriate units as expressed in the comments box in the Rehabilitation Technology Database injection in m of slurry injected per day masonry and concrete sheet pile in m of placed material per day D 2 2 3 Material of new sewer This characteristic provides the most common type of material used by the rehabilitation technology This is quite clear for renovation and replacement techniques in which there is a new pipe or at least a coating new material in the existing conduit In the case of repaired pi
98. g In this method the bursting head is a cone shaped soil displacement hammer It is driven by compressed air and operated at a rate of 180 to 580 blows minute The percussive action of the bursting creates a small fracture with every stroke and thus continuously cracks and breaks the old pipe This action is combined with the tension from the winch cable which is inserted through the old pipe and attached to the front of the bursting head It keeps the bursting head pressed against the existing pipe wall and pulls the new pipe behind the head The air pressure required for the percussion is supplied from the air u Depending on pipe bursting method employed percussive hydraulic or static respectively 53 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE compressor through a hose which is inserted through the new pipe and connected to the rear of the bursting tool The air compressor and the winch are kept at constant pressure and tension values respectively The bursting process continues with little operator intervention until the bursting head comes to the reception pit Benefits v Widely available and experienced method Drawbacks x Vibrations may affect other nearby services so all underground structures within one meter of the existing sewer should be rehabilitated must be excavated and exposed to avoid damage that may occur due to the forces being transmitted and the displacement of soil by this bursting techni
99. g on pipe diameter a cutting ring may be welded if the end is left open Lubrication may be required for open ended cutters soil core which forms in the steel casing be removed using an auger compressed air or jetting After installation the product pipe is pulled through the casing In addition to new installations pipe ramming can be combined with directional drilling and used to free the product pipe during pullback or the drill pipe during pilot hole boring or reaming if it gets stuck due to hydrolock or differential pressure sticking Benefits v Thrust plates or blocks in the insertion pit are not required v This method is most valuable for installing larger pipes over shorter distances less than 20 meters and for installations at shallower depths compared to HDD v Can save both total installation time and costs under favorable conditions compared to other trenchless methods such as augering and directional drilling v It is suitable for all ground conditions except solid rock v Little or no soil disruption v Little disruption to traffic Drawbacks x method is non steerable x Notsuitable for soil containing boulders x Ground investigation essential C 3 2 2 6 Auger boring Auger boring is the process of simultaneously jacking casing through the earth between two pre sunk shafts while removing the spoil inside the encasement with a rotating flight auger The casing supports the surro
100. gy survey E 2 1 How to guide In the following a step by step guide is presented of the functions and D12 Rehabilitation menus of the database Search engine 1 Click the search button on the menu The search form window opens 2 Fill in the form with your search requirements Please note that iv VI vii The more criteria you enter the less techniques you find Start with broad search criteria and narrow them down Kind of defect solved click help button in the box and a list of the codes and their short name will pop up Searching for no more than two defects is recommended few techniques are able to solve many defects Note that 1 indicates that the technique is conditionally suitable to solve the defect which means that it will not in general be the most cost effective technology but under some conditions this could change and 2 means suitable which in general is the most cost effective technique Logical operators are not allowed in this criterion so chain search is recommended when searching for techniques 1 or 2 regarding a defect Suitable diameter use the logical operators boxes for wide searching Min and Max are the minimum and maximum diameter the technology can rehabilitate So searching for technologies able to rehabilitate pipes larger than 600mm do not use max greater 600 but rather min greater 600 95 COMPUTER AI DED REHABILITATION OF S
101. h diameter width if depth lt 4m 207 length diameter width if depth gt 4m Cost discrete piling Single pilling Digging earth transport dumping Cost sheet piling Single pilling Digging earth transport dumping F 2 4 Injection Project price formula Cement Slurry cost concrete cost 1 5 Injection equipment renting 973 day aprox yield 3 4 tn day Cost concrete cost 1 5 375 volume of cracks F 2 5 Robot Project price formula Basic price 200 h robot renting strong variations in different countries F 2 6 Short liners Regression form installers prices Cost 0 5213 diameter 291 84 length Not checked for pipes over 1000mm diameter F 2 7 Man made repairs Project price formula The basis are Masonry 50 m Invert channel 75 m semicircuplar piedes D 300mm installation excluded Concrete works 100 m includes material and manpower 100 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Average cost for invert repairs 180 m Average cost for invert vault repairs 250 m Only for man entry sewers F 2 8 Cured in place pipes CIPP Regression over final cost of works Cost 537 109 Length 235 number_of_Service_Connections 17 Diameter For small diameter pipes Regression over installers price Cost 74 145 0074 length Not checked for pipes over 1200mm diameter F 2 9 Horizontal directional drilling HD
102. hardener is critical for durability and cohesiveness Because of this computerized machinery with heating devices is used in the application spinner head is winched through the main at a required speed After lining the ends of the water main are capped and the resin is allowed to cure for a specified time normally 16 hours at an ambient temperature must be above 3 C A uniform smooth coating typically 1mm thick is achieved Oncompleting the curing process the pipe should be inspected visually or by CCTV Epoxy A variety of epoxy systems are available all require extensive cure times at ambient temperatures Most were developed for clean water applications but some are used in a variety of sewer applications Polyurethane Cure time of PU systems is much shorter than that of epoxy however the quality of the cured resin system is much more sensitive to external conditions 39 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Benefits v There is very little loss of pipe diameter 2 mm as a total thickness of 1 mm of epoxy is applied v improved interior friction coefficient increases hydraulic capabilities Laterals do not need reconnection v Water service connections to the newly relined water main do not have to be blown with air as is the case for the cement mortar lining application method v Sealing technique v method can accommodate a variety of diameters and cross s
103. heet piling Metallic usually steel sheets are vertically jacked in the soil vibrating or striking them with specialized machinery and interlocked together Once the sheet pile is finished the excavation can begin In the case of linear infrastructures e g sewers the sheet pile is constructed along the infrastructure and in both sides In this cases the digging material is the soil between the walls intrados or soffit space Maximum depth of excavation is in function of sheet pile dimensions and soil characteristics The access to sewer is now opencast Any kind of repair can be done Once repaired the intrados is fulfilled with adequate material earth granulates 20 COMPUTER DED REHABILITATION OF SEWER NETWORKS Metallic sheet can now be retrieved and the surface pavement restored Benefits v 45454 Drawbacks x As the structural element can be retrieved costs are much minor than for concrete sheet piles More adjusted and controlled working area required than trenching or shoring Less earth excavation volume Suitable even in hard soils and soft rocks Suitable for all pipe materials Ability to overcome unknown obstructions In some cases other infrastructure can be rehabilitated or replaced at the same time allowing for coordination of work and sharing of costs Depths are usually not much deeper than 5 8 meters Strong vibration necessary to sheet jacking so many disturbances
104. her a wire rope or steel rods rear of the expander is connected to the new pipe splitter and the new pipe are launched from the insertion pit Old pipe is opened out and unwrapped into surrounding soil At the same time the new pipe is pulled in the annulus left by the expanding operation Benefits Usable in ductile pipes Cleaning of the existing pipe is not necessary Existing manholes can be used as launch pits A larger diameter pipe can be inserted Continuous pipe HDPE or discrete joined pipe such as PVC can be used Progress rates are greater than open cut 4545 56 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Drawbacks x Pit excavations are normally required to accommodate the replacement of pipe sections x Ground surface heaving can occur if the depth of cover is too little or soil is un compacted x All sewer services must be disconnected before splitting and reconnected to the new sewer afterward x There is little vibration to disrupt adjacent services x Over pumping required C 3 2 1 6 Pipe eating Pipe eating is a technique based on microtunneling 2 in which a defective pipe is excavated in situ together with the surrounding ground to make a path for a larger pipeline The micro tunneling shield machine will usually need some crushing capability to perform effectively The replacement pipes are connected to the back of the tunneling shield The defective pip
105. ice pull plates and a cylindrical expander or plug which allows the system to handle both size for size replacement and upsizing Process Excavation of the bore is carried out from the jacking shield which consists of a steel cylinder Excavation can be carried out by hand mechanical excavators or remote controlled tunneling shields pulling device a pulling rod assembly is inserted through the existing pipe t s attached to the extraction machine on one end and tool assembly which is connected to the replacement pipe on the other end new pipe is placed against the old pipe and as the new pipe is jacked the old pipe is pulled toward a reception pit or manhole At the reception pit the existing pipe is broken into pieces and removed Spoil may be removed by auger flight slurry pumping and for man entry constructions by skip trucks and conveyers Auger flight is preferred for short drives and slurry pumping for long drives especially in the presence of groundwater Benefits v be used in structural applications v System allows up sizing pipe diameter v Sealing technique Pipe extraction follows basically the same idea than pipe ejection but pulling the old pipe instead of pushing it 60 COMPUTER AI DED REHABILITATION OF SEWER NETWORKS CARE v Only pit damage done in surface pavement Pit dimension can be important in large diameters v No fragments from the old pipe are lef
106. information was collected in a chart in a first instance see previous chapter and latter exported to a database A database file makes possible a dynamic inquire from the Multi Criteria Decision Tool created in the CARE S project providing the list of techniques able to solve a specific defect in the sewer or drainage system under defined environment conditions and dimensions see Applicability conditions or requirements This database also provides data for the calculation of socio economic costs like the environmental costs see Environmental impacts the disturbance to citizens working area required time to develop the works etc and others see Technique rates and characteristics The software used is MS access due to its availability it s the most common database software attainable from any end user its compatibility with other tools of CARE S project and the possibility of providing this database as a stand alone tool The database can be updated with new techniques or characteristics easily giving the end user the possibility to adjust this tool to his experience and local requirements 92 COMPUTER DED REHABILITATION OF SEWER NETWORKS BEER 2 iat heri ei rdi m 4 HE amm Figure 1 View of the Rehabilitation technologies database From left to right the menu box partial view of a rehabilitation technique card and th
107. inly it was decided what characteristics were going to be used by Multicriteria Decision System applicability conditions and which will remain as just general information are practical results of the workshop The RTsDB was checked by all WP4 partners to adapt the system to the different countries and many implementation were made on it The operational Methods were linked to this DB as explained in the D11 report Survey of operational options 1 The definitions of these three categories were first introduced in this standard nevertheless they are clearly separated as the three branches of rehabilitation methods in the EN 13566 1 Plastic piping systems for renovation of underground non pressure drainage and sewerage networks 14 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE B 3 Rehabilitation techniques Sewerage conduits are subjected to several conditions that may cause a variety of damages As internal causes of sewer damage it can be can found gt quality of flow that may have low pH values frequently with origin in industrial spillage that disaggregates concrete pipes gt hydraulic performance that may cause stress for internal pressure gt network age that presents natural wasting for use along years of low maintenance investment gt network construction time because it becomes clear that in different countries and cities the infrastructure development has not been done with a good q
108. into contact with the environment An novel variation on the winch installation is to cast a polymeric liner into place typically this process consist of the following stages the liner consists of two sleeves with a resin based cement mortar sandwiched between them pre liner is pulled through the length of the pipe A tailor made studded HDPE in liner is mechanically folded and pulled through the outer liner Both section ends are sealed the liner is inflated using water pressure annular void created by the studding is grouted to fix the liner permanently in place Benefits v Installation is relatively fast with minimal excavation required v toffers a choice of different resins to suit the application v The fabric material to be used can be tailored in the factory to suit the diameter of the host pipe Non circular sections can also be lined if required CIPP liners can negotiate 90 bends within the host pipe The system can accommodate very long lengths It fits in very tightly to the host pipe and resists thermal expansions or contractions An improved interior friction coefficient may increase hydraulic capabilities The reduction in cross section is minimized Usually no grouting required It can be used in structural semi structural and non structural applications CIPP is widely available There is minimal disruption at the surface as access can take place from existing manholes
109. ints with a low profile bell HDPE pipe are either butt fused thermal process or joined together by electrofusion in various possible lengths above ground then inserted into the host sewer at entry pits A sliplined pipe substantially reduces the cross sectional area of the pipe However the reduction in friction with the lined pipe compared to the previous old unlined pipe can partially compensate for the reduced internal diameter Hydraulic requirements must be considered carefully before selecting sliplining as a preferred alternative Grouting the gap between the new and the old pipe annular space is an important step in the sliplining process to maintain the structural stability of the new pipe Process Mandrel testing of the existing pipe is required to ensure the host pipe can accommodate the sliplining Or even better CCTV inspection can be made to map the ovality of the pipe nose cone is fitted to the leading end of the liner to prevent snagging and to aid attachment of the winch wire bond A lead in trench and rollers allows the liner to be inserted smoothly into the host pipe Pipe lengths may be jointed into strings to form a continuous pipe or jointed prior to insertion where only limited space is available All external weld beads must be removed to facilitate insertion sliplined pipe is then reconnected to the existing sewer at both ends Laterals need to be identified and remade prior to g
110. ircumferential fissure IRSEF OULR comlex CE 12222222 RC E F O U L R nn RX E F O U LR fissure in joint homocentric fissure BK B E F O U missing brick corrosion missing wall corrosion products on surface A B D connecting pipe projecting into the pipeline A the position of the connection is incorrect B there is a gap between the end of connecting pipe and the main pipe there is a partial gap around part of the circumference of the connecting pipe between the end of connecting pipe and the main pipe connecting pipe is damaged connecting pipe is blocked other mechanical damage chemical attack general e g corrosion of reinforcement chemical attack biochemical attack due to sulphuric acid damage above the water level chemical attack attack by wastewater damage below the water level cause not evident 111 5 E 5 mir 2 gt 8 E F U LR B E F O ULL mechanical abrasion corrosion C B E F O U L 7 In m iU 2 SN E F O L R botched up connecting pipe AR B E F O U LR fissure in connecting pipe 5 COMPUTER AI DED REHABILITATION OF SEWER NETWORKS CARE BB Codes relating to the operation of the pipeline Foots A leoa S S S y B lindependent fine rodis Ep C jempemesdeods TT BBB Attached deposits frosin
111. ires special extrusion dies due to non standard pipe diameters Tight radius bends have to be cut out Lateral connections have to be excavated or robotically re opened A single diameter liner cannot cope with a major size change in host pipe bore 41 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE C 2 2 2 2 Folded liners fold amp form In this method pipe section is passed through a re shaping tool either on site or immediately after manufacture in the factory Factory formed pipe is typically permanently formed into a U shape configuration Folding the liner prior to installation can result in a large reductions in cross section which maximized the annular gap during insertion Resultant lower winch loads enable longer lengths to be installed and tighter bends negotiated The folded liner is then winched into the host pipe and re rounded using a combination of heat and pressure and at times a device propelled through the liner PE liners are preferred for pressure applications while PVC systems are mainly used for gravity sewers It is most successful with few connections Process Site folded liners are welded immediately prior to installation For some PVC liners heating of the coil is required to soften the liner prior to insertion New pipe is introduced in the old pipe with the help of winches Containment tubes or sleeves are sometimes used to protect the liner during insertion and prevent rupture during
112. it zigzag distribution Injection pits are dug to projected depth Mortar slurry is grouted directly through injection drills made in the shafts in the defined directions to cover all the corresponding area From each shaft one or several injection drills are made sequentially new drill is made only after previous grouting is finished only cased drills might be done previously in some conditions Process is repeated in all the injection shafts Operation is finished when shafts are back filled compacted and repaved Benefits v Improves general soil stability v If it s carefully designed and taken on be an structural technique v be used for no man entry sewers but rarely will be the best solution for small diameters Drawbacks x x Only suitable to stabilize soils doesn t repairs directly the sewer Surface damage is produced and digging required although only in few locations Requires soil characterization Difficult to measure in the project To complete sewer repair other techniques like fissure sealing are required 35 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE C 2 Renovation techniques C 2 1 Dig technology C 2 1 1 Open cut C 2 1 1 1 Conventional trench See 1 1 1 1 C 2 1 2 Semi open cut C 2 1 2 1 Shoring and Trench box modificated shoring See 1 1 2 1 C 2 1 2 2 Concrete sheet pile See 1 1 2 2 C 2 1 2 3 Sheet pile See 1 1 2 3 C 2 2
113. ively large diameter v There is reduced disruption to surface operations such as major thoroughfares railway tracks rivers buildings and trees v There is less disruption to buried infrastructure compared to the open cut method v Printout of line and level available v It allows for a new sewer alignment Drawbacks x Requires a large site footprint space requirements for HDD rigs can range from a 30m wide by 45m long entry plot for a 300m crossing up to 60 wide by 90 long area for crossing of 900 or more meters x On the pipe side of the crossing sufficient temporary space should be rented to allow fusing and joining the polyethylene carrier pipe in a continuous string x Exact pipe alignment can be difficult to attain although still fairly accurate 67 COMPUTER AI DED REHABILITATION OF SEWER NETWORKS CARE x Equipment has difficulty operating in granular soils Cobble and gravel seams might cause difficulties during the pilot bore and pullback stages x Ground investigation is essential x On large installations large quantities of drilling mud are used creating the potential risk of frac out and costly slurry management actions i e recycling containment and disposal x HDD requires consistent and good soil conditions e g firm clay boulderless cohesive tills for good performance C 3 2 3 3 Guided drilling mini HDD The Industry distinguishes between mini HDD and conventional HDD which is sometimes
114. l conditions Also contitionally suitable is linked to techniques that in general seem disproportionate to solve a defect for example missing mortar BAE in masonry man entry sewers can be solved with liners but probably pointing is a more cost benefit optimized option In conclusion RTs classified as conditionally suitable are techniques that can t be discarded as a possible technical solution but its convenience must be checked for the specific conditions of each case The techniques considered non suitable to solve a determinate defect are those whose application in normal conditions is not possible or the cost benefit is very disproporcionate 80 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE D 2 1 2 Technology applicable to sewers manholes laterals This characteristics informs about the suitability of the RT to be applied to different parts of the asset Manholes and lateral connections from houses or gullies are also parts of the network that require rehabilitation even that in general these does not suffer the same loading conditions that the sewer itself Most of the techniques are suitable for sewers but a few of them only are used in small diameters 250 mm or smaller and so these are considered to be only useful for lateral connections D 2 1 3 Diameter of existing sewer Indicates the minimum and maximum size in millimeters the technique can cope with These measures may be vary in local markets as no
115. l in place Benefits This technology is specific to pipe joint issues v Minimal working space is required at the surface v Itis a low cost alternative 32 COMPUTER AI DED REHABILITATION OF SEWER NETWORKS CARE v Very low social cost as few traffic disturbances noise or dust produced Drawbacks x only be used in man entry sewers It does not address other possible pipeline deficiencies Not suitable for non circular sewers It does not provide structural repair Bypass pumping is required x x x C 1 2 4 4 Resin injection As seen in injection 1 2 3 4 injections consist in grouting with any gel material the voids existing in the extrados of the sewer For no man entry sewers and plastic tubes robot devices and different resins have been developed Process CCTV sewer inspection detects the defect root protruding lateral deposit giving its precise location and dimensions In some cases sewer has to be cleaned allow the access of the robots n many cases the operation has to be done without running water and so it s necessary to cut the connections or water pumping robot is assembled with the proper devices for grouting first making small drills and then grouting resin through the drills defective reparation is guided with the aid of a CCTV It can be set in the same or in different robot repaired the robot s are pulled out and the se
116. l of pipe can be controlled v Little noise and traffic disruption compared with conventional trenching Drawbacks x Notable for plastic pipes commonly FRPM pipes used x Requires grouting x Thorough site investigation required x The soil around the tunnel is decisive for the load carrying capacity and so determinate the strength necessary for segments x High capital cost of equipment x Many security and health measures to be observed Requires highly skilled operatives C 3 2 3 9 Tunneling Full tunneling is a construction method of excavating an opening beneath the ground without continuous disturbance of the ground surface and of sufficient diameter to allow individuals to access and erect a ground support system at the location of the material excavation Full tunneling is a technique normally used for very deep installations Although primarily used for new installations applications have been included for rerouting existing sewers Benefits Y Y Y Drawbacks x x xxx There is a high level of accuracy due to the laser guided installation There is continuous tunnel support The method is applicable in deep sewer installations Tunneling needs a minimum depth of cover A tail tunnel is required for effective spoil removal full tunneling It is expensive for short stretches Extensive geotechnical information is required The potential exists for ground settlement Many security a
117. lacement pipe in the void created The system uses a pneumatic hydraulic or static bursting unit to split and break up the existing pipe compressing the materials into the surrounding soil as it progresses The new replacement pipe is simultaneously pulled or pushed with the bursting head to fill the void created The leading or nose portion of the bursting head is often smaller in diameter than the existing pipe to maintain alignment and to ensure a uniform burst The base of the bursting head is larger than the inside diameter of the existing pipe to be burst to fracture it It is also slightly larger than the outside diameter of the replacement pipe to reduce friction on the new pipe and to provide space for maneuvering the pipe The bursting head can be additionally equipped with expanding crushing arms sectional ribs or sharp blades to further promote the bursting efficacy It is possible to upsize to about 30 percent greater than the diameter of the existing pipe but this depends on soil conditions the proximity of other existing structures and the depth of cover The pulling force of the bursting unit must be maintained at a value less than the tensile strength of the replacement pipe to avoid overstressing the new pipe The replacement pipe must be installed in one continuous length and as such butt fused PE pipe is used in most cases Service connections connected to the sewer to be rehabilitated must be excavated and exposed before
118. m live flows can be accommodated through the packer Process A microtunnelling shield is adapted to allow the existing pipeline to be broken up and removed shield has a larger diameter than the existing pipeline and contains a device to crush the fragments of pipe to facilitate their removal from the shield tis moved along the route using hydraulic jacks located in the drive shaft Replacement pipes are connected to the back of the shield Anew pipe is simultaneously installed by jacking it behind the microtunneling machine Me Microtunneling is explained in 3 2 3 7 57 COMPUTER AI DED REHABILITATION OF SEWER NETWORKS CARE Benefits v This method permits in line replacement and upsizing of sewers with reduced potential for disturbing paved surfaces or adjacent utilities v No fragments from the old pipe are left in the ground v It enables sagging sewers to be realigned v systems allow the wastewater to be pumped through the shield during installation thus eliminating the need for a bypass Steering is possible within limits and can follow the alignment of existing pipe Drawbacks x The method is not suitable for the replacement of metallic or thermoplastic pipes It can be costly in comparison with pipe bursting Laterals must be removed Working space is needed above ground for ancillary construction equipment Drive and reception pits are required x C 3 2 1 7 Pipe
119. me use of shield parameters recorded during tunneling The system termed CATSBY allows all recorded data to be either stored or used to estimate some pre established key parameters that could in turn provide some indication of the ground structure interactions associated with the tunneling process These include pressures in the muck chamber as well as characteristics of the thrust resultant acting on the tunnel face Measurements are taken at regular intervals typically every 3 minutes and each parameter is characterized in terms of mean value and standard deviation These data can be used by the shield operator to check that mean values remain within acceptable levels and that no sharp changes occur in the time response of pre established key parameters The concept can be applied to a variety of project conditions and is designed with sufficient flexibility to allow adjustments to be made as required in the course of the project One particular difficulty to be emphasized with shield tunneling is the operation of the machine through the entrance and exit shafts as these junctions usually result in reduced confining pressures in the surrounding ground which could lead to critical conditions in grounds such as water bearing soils with low cohesion Break in Break out transition zones need to be introduced in these areas these should serve five main purposes 1 Ground support in the direction perpendicular to the opening 2 Face reinforceme
120. n circular sewers Mobile Equipment May enhance capacity No surface damage is produced No dig required Very low social cost as few traffic disturbances noise or dust produced Quick total working time SS 4 Drawbacks x There is the potential of ground water pollution selection of grout type is a major consideration Some companies have environmentally safe chemical solution Chemical grouting is effective when used with other technologies Size of sewer limited by volume Difficult to isolate section to be treated where surface is irregular Large volume of chemicals required Difficult quality control xxx 30 COMPUTER AI DED REHABILITATION OF SEWER NETWORKS CARE C 1 2 4 2 Mortar stabilization Mortar stabilization is a common grouting method It consists inject mortar slurry into the soil and it s widely used in civil engineering to treat slump zones and cavities To properly map the cavities several techniques may be used among we highlight the SPT standard penetration test and the non destructive test of ground penetrating test GPR or georadar Process is done to allow the grouting pipe to penetrate into soil In unstable soils the drillhole shall be stabilized with drilling fluid of bentonite or polymer slurry The head of the drilling fluid shall be kept at a level high enough to ensure sufficient stabilizing capacity in the cased or uncased drillholes
121. nd health measures to be observed High level operator experience is needed 16 Fibers Reinforced Polyester 72 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE C 3 2 3 10 Shield tunneling Shield tunneling is one of the most powerful and technically advanced systems in tunnel excavation Shield tunneling involves many systems that have been developed in the last decades The systems has grown adapting to different necessities as excavation in granular soils under high water head in heterogeneous soil conditions and other difficulties The parts of the tunneling system include Shield Hydraulic system Cutting head designed for specific soil conditions Operator Controls Transport system for removing spoil and bringing segments to the front of the tunnel Depending on the soil condition and the difficulties to be expected optimum excavation techniques will be used in each of the systems listed above One of the major advances accomplished in this field was with the introduction of shields of the pressurized type which allow tunnels to be constructed in all types of soils including sands under high water head These include the slurry shield and the Earth Pressure Balance EPB shield The first technique makes use of a bentonite slurry to stabilize the working face of the tunnel The EPB shield was developed a decade later in this case face support is obtained by retaining the spoils in the working chamber so that s
122. non steered 61 22 21 Rod pushing Thrust 12018 61 C 3 2 2 2 Impact moling pneumatic VE eet ND Ie MEE ERE 62 C 3 2 2 3 Impact moling hydraulic hammer eiie ae npn 63 aces MEC 301611001118 Mec Te cm 63 C 3 2 2 5 Pipe ramming impact 13100008 aces eei erts dl tie 64 C3226 Auger DOMNE cs dolio ca oo bui eo cen aol 65 C 3 2 3 Off line replacement 6666 ta On exam uae iab 66 C 3 2 3 1 Guided auger boring Lee tte teo dicia ede 66 C 3 2 3 2 Horizontal directional drilling HDD 67 C3233 aded drilling Oft HDD uice ei neg nuig ean 68 C 3 2 3 4 Conventional pipe jacking e aeri reet Etsi Loren s HEU EHE 68 32 3 3 Low 1030 d ce Tm 69 222319 Thrust Hole 69 000010116111 TE 70 52 98 111100110611118 o cesta eta Ma ba 71 22229 110061118 cease dara sha 72 o 2 310 511610111111611 M IR 3 MANHOLE REHABILITATION 76 C 5 LATERAL CONNECTIONS REHABILITATION sssssseseseseseseseseseseseseseseseseseseseseseseseeee 77 D REHABILITATION TECHNIQUES CHART DE
123. nstructed in sizes from 1000 to 3000 mm diameter All of the hydraulic and electric power for the operation is located outside the shaft The operator sits in the front of the shield and operates the valves and controls of the tunnel excavator machine and the segment erector All of the hydraulic and electric power for the operation is located outside the shaft The tunnel machine is connected to the power supply by cables that are mounted on the inside of the new tunnel Conveyors or muck cars are used to remove the spoil from the tunnel The muck cars may be battery operated These cars are also used to bring the new pipe segments to the front of the tunnel where they are installed Three identical concrete segments with radially and axially integrated tongue and groove are combined as a pipe The length of each segment is between 60 and 75 cm depending an the diameter of the pipe In this application the driving shield has an open face In some cases the tool for soil excavation is a drag bucket Protected by the driving shield a pipe made of pre fabricated segments or tubbings is installed The pipe exclusively provides the counterpressure for the further shield driving process So the difference between this building method and others is that the pipe is not jacked through the soil by large hydraulic forces Once the segments have been installed the pipeline does not move any longer Process Identical segments with tongue and groove compres
124. nt to ensure ground stability ahead of the shield using a confining pressure limited to the thrust reaction capacity 3 Ground support in the vault to limit decompression effects so that settlements can be controlled despite reduced confining pressures 4 Control of water pressures and water ingress so that blow in and flood can be prevented 5 Guidance to the TBM along the first meters of drive to prevent sinking of the machine to occur Several treatment solutions have been made available to cope with these difficulties in particular techniques based on partial ground substitution have proven to be fully efficient in soft water bearing grounds Process excavator digs up the soil and carries it to a conveyor belt The shield is driven forward by means of the hydraulic cylinder The advance rate for each pipe is between 60 and 75 cm The completed pipe in the tunnel serves as a thrust wall for the hydraulic cylinders pushing the tunnel shield hydraulic cylinders are retracted to make room for the installation of the next segments which make up the pipe After the new pipe is installed and grouted the hydraulic cylinders push the tunnel shield forward Benefits v System for large diameters v There is a high level of accuracy due to the laser guided installation 74 COMPUTER DED REHABILITATION OF SEWER NETWORKS CARE v There is continuous tunnel support Shield tunneling is suitable in uns
125. ocessecssocssoosscosesoesssecesocesoosssoessseessoessocsse 51 Cul TECHNOLOGY er er 51 22121 Open e eas 51 C XLLI Conventional teneli d dito iier niei 51 Ceu Mibi ciui E 51 C 3 1 2 1 Shoring and Trench box modificated shoring sss 51 C3122 Concrete sheet tyes ea die o Pa adnate 21 AFER SA 51 ELT Mole ploughing mem eee etm dL 51 uou 1 55 TECHNOLOGY ie 52 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE C3 2 1 00 1016 r placement 2 52 C 3 2 1 1 Pipe bursting percussive 52 C 3 2 1 2 Pipe bursting hydraulic SH I fentit pt 54 C 3 2 1 3 Pipe 0015008 SIUE usen ideis dosi rtm piss 54 C 3 2 1 4 Controlled line and grade system CLG eere 55 Bes E UU UU UU T T 56 AW PERCOEMEga E onm 57 3 2 1 T 58 C 3 2 1 8 Pipe crushing implosion 58 C 3 2 1 9 Pipe ejection modified pipe 59 C 3 2 1 10 Pipe extraction modified static pull 60 C3211411 1106 onm 61 C322 Off line replacement
126. oducts and techniques for lateral rehabilitation Trenchless Technology Center Ruston LA Jadranka Simecevic 2002 Currently available products and techniques for manhole rehabilitation Trenchless Technology Center Ruston LA Kirsten Atkinson 1999 Sewer rehabilitation and renovation techniques Subterra developments UK Nick Orman et al 2001 Sewerage rehabilitation manual WRc UK NRC CNRC National Research Council Canada 2003 Selection of technologies for sewer rehabilitation and replacement Canada Office of Water 1999 Collection systems O amp M fact sheet Trenchless sewer rehabilitation EPA USA S nchez Sanjuan 1994 T cnicas de rehabitaci n y renovaci n sin zanja para canalizaciones de agua potable y saneamianto AEAS Spanish society of water supply and sewerage Jerez de la Frontera Spain R Sterling J Simecevic 2001 Guidelines for pipebursting ERDC USACE R Sterling J Simecevic 2001 Guidelines for Impact Moling ERDC USACE R Sterling J Simecevic 2001 Guidelines for pipe ramming ERDC USACE Internet sites http www asce org http www apwa net http www awwa org http www csiro au http www epa gov http www hrwallingford co uk http www infraguide gc ca http www istt com http www latech edu tech engr ttc index html http www microtunneling com http www no dig com http
127. ogy is potentially dangerous for the groundwater when this water is used as a resource There are techniques grouting injection of chemicals that have been rejected in specific conditions due to its pollution potential that can cause contamination of the watertable or soil close to the sewer D 2 3 4 Acoustic pollution Noise Acoustic pollution produced by earth works and machinery during rehabilitation is an important issue for social cost assessment This parameter can also be combined with night technologies to rule out rehabilitation technologies that could be done by night but are not suitable because of the noise D 2 3 5 Air pollution Dust Works usually produce air pollution essentially dust produced by earth works In general pollution due to exhaust of machinery is minor Trenchless solutions are more environmental friendly in this aspect Dust causes citizens complaints and so its convenient to consider this impact when working in urban areas 90 mpplicabliity conditions requitements technology perfarmance f eharactoristics environmental impact comments delet endos va poete 26918920 alta meal ol misieg Svetem ar duree melle iive p percer ater rived tact arcere
128. ointed either outside or inside the pipeline to form a continuous lining These pipe lengths can be joined by collar or collarless methods such as screw threads on the ends of the pipes or snap lock joints This means shorter lengths of pipe can be inserted via the entry pit and less working space is required at the surface of the job site This method can be used for man entry or non man entry pipelines Process The typical procedure is dependent on the pipe size and the materials used Lateral connections are disconnected ndividual lining units are passed into the pipeline via manholes or special access shafts Man entry Lining begins from furthermost point Units are positioned and joined Small section lined then grouted before proceeding to next section Non Man Entry Units joined in manhole or access shaft Units are pushed or pulled into pipeline until entire length has been lined Reinforced materials Glass reinforced plastic glass reinforced cement and reinforced ferrocement can be used for pressure and gravity applications Units are either cast filament wound or centrifugally spun into pipe sections Pipes are joined by spigot and socket or by collared butt joints Some joints require additional sealing 44 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Plastic materials Polyethylene or polypropylene units Typically used for non man entry applications Jointed by thre
129. one If enough data were available it has been possible to calculate a regression formula Due to a lack of incomplete information in most of the data this calculation has been possible in few techniques Regression over installers price Some installers have provided their prices for their techniques for different diameters and conditions These prices are not really their final offer to a determinate work but a basis price It can vary significantly depending on working conditions and boundaries and of course of the competitors for the tender Cost drivers This option has been used when rehabilitation cost depend clearly on determinate factors drivers like materials price concrete plastic working surroundings depth pipe length number of existing connections etc Then the final cost is assessed by comparison with default conditions and multiplying factors In the Cost Tool user can add new cost drivers change default costs or multiplying factors Project price formula Wherever insufficient data to use previous methods have been obtained it has been considered a better option to construct the price as it is done in a project Some basic prices have been fixed in the Cost Tool but of course these can be changed by the user to adapt them to local conditions and experience Unfortunately there are some techniques for which no valid cost formula has been reached The cause can be the novelty of the method E G Control Line and
130. opied in the RT formulae table Figure 6 and they can be used for defining new formulae for cost computation The RT formulae table has the following structure two columns showing Rehabilitation technique codes and names on the top of the list there is a Default command that returns the default CARE S list of technologies the user can modify technologies names codes or adding new ones the maximum number of technologies is equal to 100 CARE S default list is containing 76 technologies at the moment the central part of the table is used for intermediate computing of factors that compose the total cost coefficients that strictly depend on one or some factors can be edited and computed in the spreadsheet area and then multiplied for obtaining the final cost In every table row a Default switch can be used for returning CARE S default formulae or user defined ones that can be manually written in the last two columns using the same syntax as usual Excel the last two columns are used for total cost computation with two possible formulae that can define a range as someone asked in the very beginning of this cost tool or a summer winter cost 105 COMPUTER DED REHABILITATION OF SEWER NETWORKS CARE mu Pipe characteristics RT_costs RT Formulas Id ar Figure 6 Cost Formulae table The third button in the toolbar displayed in figure 1 is the save button with a
131. ot devices do the grouting Once repaired the robot s are pulled out and the service restored Benefits v lt lt lt lt Very useful for small localized sewer damages No surface damage is produced No dig required Very low social cost as few traffic disturbances noise or dust produced Relatively quick total working time compared with digging methods No deep limit and achieves longitudes of sewer up to 100m from one single manhole Drawbacks x Not suitable for grave or generalized fractures High level of operator skill required Very specific machinery employed robots Low operations performance Not suitable for all pipe materials C 1 2 1 2 Milling robot The milling robot removes any roots which have penetrated grinds off protruding lateral connections and removes hard deposits such as concrete With its interchangeable tools it can be used for milling drilling or grinding Process It s the same than for injection CCTV sewer inspection detects the defect root protruding lateral deposit giving its precise location and dimensions In some cases sewer has to be cleaned allow the access of the robots In many cases the operation has to be done without running water and so it s necessary to cut the connections or water pumping The robot is assembled with the proper devices for milling and introduced in the sewer trough the manhole The defective reparation is guid
132. pair the invert It s ideally used if sewer performance is adequate but benchings are not so correct and channel is too wasted Precast elements are available in several materials but plastic and stoneware are preferred because of their longer durability to chemical agents and waste Process sewer is cleaned the water canalized in small pipes or pumped and sewer length is provided with electric light A preliminary task of demolition and extraction of damaged elements is done operative reconstructs the defective with precast elements Usually there are assembled together or placed with mortar stoneware half pipe tiles or chemicals plastic elements auxiliary installations are taken away and the sewer is back to service Benefits v Very useful for invert or channel collapses when walls and crown of section remain in adequate performance v Sealing technique v Suitable for most sewer materials v surface damage is produced No dig required v Very low social cost as few traffic disturbances noise or dust produced Drawbacks x structural technique although it can enhance structural capability x Only suitable for man entry sewers x Many security and health measures to be observed 29 COMPUTER AI DED REHABILITATION OF SEWER NETWORKS CARE x Many powerman required that can increase the cost x Relatively slow process but not so much as in situ method C
133. pe the reversion process begins either elevating the temperature leaving at ambient temperature or using cold water Lateral connections are reopened and sewer is back to service Benefits v lt lt lt 4 SN S There is minimal loss of pipe diameter and no grouting requirement when compared to the traditional sliplining technique The improved interior friction coefficient can increase hydraulic capabilities Long lengths of structural liner can be inserted Sealing technique The liner can be selected to provide either full structural integrity or semi structural integrity depending on the condition of the host pipe Some bends can be negotiated There s no need of a completely clean neither dry sewer Method can be applied even if infiltration exists No grouting required It is rapid and causes little disturbance to other utilities Drawbacks x Sufficient site space is required to accommodate butt fusion welding of pipes before the diameter reduction and during insertion Only circular cross section pipes can be lined Obstructions deformed host pipes dimensional irregularities alignment of the host pipe and displaced joints must be considered because they can inhibit lining process So the host pipe needs surveying cleaning and preparation The energy required to reduce the pipe diameter increases with larger pipe sizes and greater wall thickness Manufactured pipe for insertion usually requ
134. pen cut projects can be substantial during construction x Large volumes of earth works required high transport costs although minor than for open trench x Risk of landslide and consequently risk for operators C 1 1 2 2 Concrete sheet pile This method consist on the construction of a concrete wall in the earth and a later digging of the soffit intrados soil It s a common way of constructing subterranean infrastructures parkings tanks Process process is usually made in lengths of wall from 2 6m to over 5 meters depending on Soil characteristics and machinery used Vertical digging of a narrow and deep trench Digging machinery allows excavation for usual widths of 45 60 80cm special machinery arrives to 100 120cm and maximum depths over 25 m Steel reinforcement already mounted is placed in the trench Concrete is pumped in the trench process continues with the next length the concrete sheetpile is finished and set up the excavation can begin In the case of linear infrastructures e g sewers the sheet pile is constructed along the infrastructure and in both sides In this cases the digging material is the soil between the walls intrados or soffit space Maximum depth of excavation is in function of sheet pile dimensions and soil characteristics The access to sewer is now opencast Any kind of repair can be done 19 COMPUTER DED REHABILITATION OF SEWE
135. pes there are some cases in which the technique does not provide new material to the pipe milling or root cutting techniques or the material provided does not became a significant part of the existing sewer grouting methods In these last cases the value of this field is null The material of the new sewer is of significant importance in order to know the new roughness of the sewer inside which is an important parameter for the calculation of the sewer hydraulic capacity D 2 2 4 Hydraulic performance after rehabilitation The rehabilitation technologies may produce a marked difference in the hydraulic capacity of a conduit As it s well known the hydraulic capacity of a single conduit is determined by 3 factors o The cross section the size area and shape hydraulic radius of the sewer may change form the original conditions also from the actual conditions by the use of most rehabilitation technologies Some techniques are specifically developed to restore the free area of the cross section like the root cutting methods or the milling robot also the rerounding techniques have been developed to correct the circular cross sections that have become ovoid But there are many techniques that in fact reduce the existing cross section although usually this reduction is only in some millimeters and thanks to 18 This is particularly important in techniques that require intensive quantity of materials for example sheet pilling of concrete
136. pes can make it difficult to insert the winch cable C 3 2 2 Off line replacement non steered C 3 2 2 1 Rod pushing Thrust Boring Directional Rod Pushing is a conventional earth boring system This method forms a pilot bore by driving a closed pipe head with rigid attachment from a launch pit into the soil which is displaced Process 61 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Launch pit is dug Head pipe is pushed through the soil with the help of the rigid attachment thrusting creating a bore pipe is replaced meanwhile the bore is done Benefits v Low cost v Fast and simple set up v Replacement pipe can be PVC or PE v Only pit damage done in surface pavement v Noise and traffic disruption less than conventional trenching Drawbacks x Not suitable for hard soils x Very limited steering and monitoring capability If steered a locator will be necessary x Only suitable for short lengths and small diameters C 3 2 2 2 Impact moling pneumatic hammer Impact moles consist of an enclosed steel tube containing an air powered piston also referred as the striker that strikes the nose of the tool driving it forward A bore into which a small diameter new pipeline can be pulled is formed by displacing and compacting the soil laterally The friction between the ground and the mole body prevents the mole from rebounding backwards Repeated impacts of the piston advance the whole unit through
137. playing a tablet The RT formulae spreadsheet is revealed 4 Go to the RT formulae spreadsheet and modify cost drivers Figure 5 including new variables or modifying the existing ones As an example introduce a new variable called Need for dust reduction i Introduce a new variable called Need for dust reduction Figure 9 ii Define it as a List iii Introduce two possible values Yes and No iv Put No as Demo value 107 COMPUTER DED REHABILITATION OF SEWER NETWORKS CARE Select Save in the Operation row Need for dust reduction No Figure 9 example of a new cost driver 5 Go to the cost formulae table on the right of the RT Cost spreadsheet Figure 6 and modify the cost formulae for every needed technology 108 COMPUTER DED REHABILITATION OF SEWER NETWORKS G REFERENCES The next references has been consulted for the elaboration of this report Angel Villanueva 2002 Gesti n avanzada de la rehabilitaci n CLABSA Spain CEN 2002 Plastic piping systems for renovation of underground non pressure drainage and sewerage networks EN 13566 EU D Stein 1994 Rehabilitation of sewer systems European Water Polution Control Volume 4 5 1994 pp49 56 Gue amp Partners SDN BHD 1999 Specification for Cavity and Slumpzone Probing and Compaction Grout Treatment Malaysia Jadranka Simecevic 2001 Currently available pr
138. pose to be compensated by surrounding soil In the case of lacking of this compacted soil sewer fissuring or cracking may be produced To prevent this pathology or to cure it next process is followed Process For detecting gaps behind walls and vaults most suitable inspection technique is georadar but expertise detailed visual inspection may be enough in severe damaged sewers In this case a simple way of checking the correct pathology diagnosis is introducing a thin rod through the fractures verifying that soil behind the wall is not compacted when rod penetrates effortlessly the defective zone has been defined several proceedings may be followed but the general idea is that a part of the vault or wall is dissembled to let soil dumping into gaps This process must be done in thin layers depending on kind of soil used for back filling this can be from 20cm to 50cm After each filling layer soil is compacted with compacting devices There s a wide range of possibilities depending on compacting degree required soil used vibration allowed dimensions of soil to compact etc each layer has been compacted and compacted soil encircles the sewer the wall or vault is reconstructed Finally fissures and cracks must be repaired using specific repair technique Benefits v Structural and sealing technique v surface damage is produced No dig required v Very low social cost as few traffic distur
139. que C 3 2 1 2 Pipe bursting hydraulic In the hydraulic expansion system the bursting process advances from the insertion pit to the reception pulling pit in sequences which are repeated until the full length of the existing pipe is replaced In each sequence one segment of the pipe which matches the length of the bursting head is burst in two steps first the bursting head is pulled into the old pipe for the length of the segment then the head is expanded laterally and the resultant perpendicular force breaks the pipe and forces the pipe fragments into the surrounding soil The bursting head is pulled forward with a winch cable which is inserted through the old pipe from the reception pit and attached to the front of the bursting head The rear of the bursting head is connected to the replacement pipe and also the hydraulic supply lines are inserted through the replacement pipe The bursting head consists of four or more interlocking segments which are hinged at the ends and at the middle An axially mounted hydraulic piston drives the lateral expansion and contraction of the head Benefits v Hydraulic methods claim to a more powerful bursting action than pneumatic and there is little vibration to disrupt adjacent services Drawbacks x Relatively higher cost than pneumatic pipe bursting C 3 2 1 3 Pipe bursting static In the static pull system the force for breaking of the existing pipe comes only from pulling the burs
140. ques and improvements in the existing ones that provide even better solutions to rehabilitation problems 16 COMPUTER AI DED REHABILITATION OF SEWER NETWORKS CARE C REHABILITATION TECHNIQUES C 1 Repair techniques C 1 1 Dig technologies Digging techniques represent the most ordinary way for network rehabilitation with a quite low technical development when compared to most trenchless technologies Nevertheless one of its advantages is its versatility that makes dig technologies be able to repair renovate and replace sewers manholes and laterals 1 1 1 Open cut C 1 1 1 1 Conventional trench This method consists on the excavation of a trench that permits the opencast access to existing sewer for repair This technique is widely used also for renovation and renewal Process Removal of existing pavement with manual and mechanic means Transport of resulting products to a rubbish dump excavation using mechanical digging or hand digging if other urban services could be damaged The trench is normally wide enough for operative to carry out repair works Depending on the depth of the trench local regulations and soil conditions sloping and or benching should be required to prevent risk of collapse De watering may also be required under watertable f operation involves the substitution of a length of pipe a layer of bedding material is laid along the bottom of the trench and the pipe laid on
141. r after rehabilitation This characteristic has been characterized as not changed when the rehabilitation works does not influence in the sewer internal size increased if the section is significantly improved its diameter or reduced for the rehabilitation techniques that usually have as consequence a reduction of sewer cross section In this sense it must be remarked that due to the large variety of installers materials and conditions even for the same technique it s almost impossible to asses an exact value for this characteristic For example cured in place techniques even if they use the same curing system present considerable pipe thick variation depending on pipe diameter and pressure design Different manufacturer present also significant variations for similar conditions As consequence of this the simplification made grouping the changes in simple categories is convenient Some techniques may be marked as combinations of these factors if the result depends on existing sewer size manufacturer of the new pipe etc Seems reasonable that a technique that reduces in 10cm the existing sewer diameter could be considered as a significant reduction of cross section in a 150mm pipe but may be not be important if it s carefully done a 2500mm main D 2 1 8 Need to cut off temporally the service connection It s important to know if the technique requires to stop the flow of the lateral connections to be carried out This
142. ramming impact ramming Pipe ramming is a trenchless method for installation of steel pipes or casings in which a pneumatic tool is used to hammer the pipe or the casing into the ground while the excess soil from creating the borehole is removed to the surface The method is frequently used under railway and road embankments Pipe ramming is typically used for horizontal installations but can also be applied for vertical projects such as piling driving or micro piling Process method typically requires excavation of two pits A pneumatic hammer based on the designs of an impact mole is attached to the casing is attached to minimize damage to the casing usually steel pipe 64 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE casing is lined up in the desired direction and pneumatic hammer placed behind it entire casing may be rammed at once or sections added during the operation The choice depends on the available space for an insertion pit setup and ground conditions When shorter pipe segments are rammed the ramming tool drives each pipe segment for its length through the ground and then returns back to the tool s original position for the new segment that is to be welded or mechanically attached to the previous segment already in the ground Pipe is driven into the ground with repeated percussive blows The front end of the casing may be closed or open dependin
143. rator skill required Quite specific devices employed nevertheless the use of packers is each day more common x An expander or packer is a cylindrical device that is able to increase its diameter generally inflating with air pneumatic but sometimes mechanically In man entry sewers this process can be done hand made 24 COMPUTER AI DED REHABILITATION OF SEWER NETWORKS CARE 1 2 2 Short liners Patch repair C 1 2 2 1 Fiberglass and polymers Short liners consist on a short length 1 3m of fabric impregnated with resin positioned over the defective section of the pipeline to repair holes or fractured sections These linings are made from the same types of materials as cured in place linings typically glass or carbon fibre or polyester felt impregnated with either an epoxy or polyester resin Process liner is wrapped around a long flexible tube packer or expander assembly is winched into the defective area of the sewer The packer is inflated to push the repair lining against the internal wall of the sewer resin is cured at ambient conditions elevated temperature or by UV radiation The packer is deflated and removed Various alternative method of curing of the system can be utilized depending on the combination of resin system Ambient condition curing is the slowest and cheapest and UV light the quickest process can be set up in minutes but has a higher cost
144. red C 3 2 3 1 Guided auger boring A variation on directional drilling is guided boring This technique utilizes a similar process to directional drilling and was developed initially for electric cables and is commonly used for installation of pumped sewers of less than 300mm diameter The guided steerable drilling head is capable of following tight curves and can install up to 100m lengths Steering is achieved through articulation of the casing near the cutting head This is controllable from the drive pit This is similar to microtunneling but in guided auger boring the guidance mechanism actuator sited in the drive shaft e g a hydraulic wrench which turns a steel casing with an asymmetric face at the cutting head The term may also be applied to those auger boring systems with rudimentary articulation of the casing near the head activated by rods from the drive pit 66 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Process The same than for auger boring C 3 2 3 2 Horizontal directional drilling HDD Horizontal drilling frequently referred to as HDD horizontal directional drilling is a pipeline installation technique involving drilling in a shallow arc using a steerable drilling head Typically used for long installations and pipe diameters greater than 300mm up to 1200mm The technique consists of several stages for installation First a pilot bore is made with a suitably sized drilling rig The bore is steere
145. referred to as maxi HDD Mini HDD rigs can typically handle pipes up to 300mm and are used primarily for utility construction in urban areas Long crossings with large diameter pipe needs bigger more powerful equipment and drill rig Process The process is the same than for HDD but HDD machines have significantly larger pullback forces Benefits v Rapid installations v There is reduced disruption to surface operations such as major thoroughfares railway tracks rivers buildings and trees v There is less disruption to buried infrastructure compared to the open cut method v Printout of line and level available It allows for a new sewer alignment Drawbacks x Only for diameters of 300mm or smaller x Entry and exit elevation differences in excess of 15 m are not recommended x Exact pipe alignment can be difficult to attain although still fairly accurate x As pipe diameter increases large volumes of drilling fluids must be pumped requiring more larger pumps and mud cleaning and storage equipment x Equipment has difficulty operating in granular soils Cobble and gravel seams might cause difficulties during the pilot bore and pullback stages x Ground investigation is essential x Mini HDD requires consistent and good soil conditions e g firm clay boulderless cohesive tills for good performance C 3 2 3 4 Conventional pipe jacking A technique for installing a pipe through a bore created by a shield machine
146. rint facility The Print all techniques function allows an operation that can otherwise be done opening and printing all the techniques one by one 97 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE F COST FORMULA CALCULATION F 1 Rehabilitation technologies costassessment One of the most important criteria to choose a technique is obviously its direct cost Unfortunately this becomes also the most difficult task The difficulties come from the fact that each sewer work is different the working conditions change the suppliers and the general construction costs may differ depending on regions and time So it s clear that the aim of assessing the direct cost for rehabilitation technologies is to give a tool for guidance and comparison purposes only The Cost Tool presented inside the CARE S project is based in few cost drivers that are used by a reduced collection of formulae Each one of the formulae is suitable for a group of rehabilitation technologies with similar cost behavior trench robotic man made injection etc This tool has an open formulation so that the end user can check the default prices and the factors used to assess the cost and change any of them to adjust it to the local conditions F 2 Cost formula calculation Cost assessment for the rehabilitation technologies has been achieved in different ways according to the data available for each technology Regression over final cost of works d
147. round in a straight line A single person can operate the mole Process Alaunch pit is excavated typically 1 5m long and 1m deep to launch the mole A reception pit is excavated of sufficient size to remove the mole 5 Steerable moles studied in 3 2 2 4 62 COMPUTER DED REHABILITATION OF SEWER NETWORKS CARE A launching cradle sets the line and level of the mole in the launch pit There are two main methods depending on soil conditions Usually the mole is launched first and creates an unsupported bore Then the mole is removed from the receiving pit and the new pipe is attached to an air hose and pulled into the bore the most popular mode of operation or the pipe is sometimes pushed into its place product pipe is directly towed into the bore during the boring procedure if soil conditions are not suitable for unsupported borehole Benefits Low operational costs Only pit damage done in surface pavement Accurate for lengths up to 10m Minimum skill required Quick system Noise and traffic disruption less than conventional trenching 4 Drawbacks x Only for small diameters Non steerable method Cannot be steered around obstructions Can only be used in compactable soils Ground investigation essential x x x x C 3 2 2 3 Impact moling hydraulic hammer The main difference between hydraulic and pneumatic hammer moling is that the first bores with an hydraulic h
148. routing Grouting is generally required to fill the void between the new and old pipes Benefits v It is rapid and causes little disturbance to other utilities v It usually provides an improved friction coefficient for improved hydraulic performance v Depending on flows installations can be done in live lines without bypass pumping v Low degree of skill required v Low social cost as few traffic disturbances noise or dust produced Drawbacks x Requires insertion pit 43 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE x The sliplined pipe is usually sized so its outside diameter is at least 10 percent smaller than the inside diameter to allow for smooth insertion This reduction in association with the wall thickness of the pipe leads to the loss of cross sectional capacity x Sliplining requires a long assembly lay down area x When short pipe sections are used there is an increased cost in the jointing techniques x Because the liners used for sliplining do not turn through elbows the alignment of the unlined pipe must be considered before selecting this technique x Poorly controlled grouting to the annular space can lead to buckling of the liner pipe x Flotation might be during grouting x Lateral connections have to be excavated or robotically re opened C 2 2 3 2 Discrete sliplining Jointed discrete lengths of pipe can also be used for sliplining applications Discrete short sections of pipe are j
149. rposes of this selection The soils have been divided in a very simple way depending on its hardness Soft Medium Hard Any And combination of these factors D 2 1 11 Working area required Urban areas in general and city centers in particular are in European countries very busy and quite often it is difficult to find space to carry out the works Rural areas does not have this problem This parameter pretends to point an idea of the room required for the work under usual conditions and rehabilitated lengths The information of the area required is completed with the number of locations in which this area is divided Some techniques allow or require distribute the working area in several sites usually two manholes or access pits The categories are Small for occupied area less than 100m Medium for areas between 100 and 75 Large for areas between 300 and 800m Whole length for occupied space over 800m and for trench technologies 17 This has motivated the successful development of so many trenchless techniques specially in the last decades 84 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE D 2 2 Technology performance Next columns of the chart provide additional information of the rehabilitation techniques This information is not considered to be decisive under normal conditions for the selection of the technique as suitable to solve a determinate problem However these data give ver
150. rtical deviation as well it is usually easier for mole operator to detect the need for the pitch correction The other operator is a tool operator who implements the required course corrections using the guidance controls The mole operator at the launch point has the control unit with continuous display of pitch and roll The resolution of the pitch sensor is much better than the resolution of depth measurement available to the tracker so the operator is the one to detect the need for the pitch correction and immediately corrects it The operator does all the steering according to the planned route To make the rotation he applies the torque to the air hose from the surface When changing the borepath direction the operator simply adjusts the roll in desired direction producing either horizontal or vertical deviation The rotation of the mole body which is required during steering is often difficult because of the friction between the mole and the soil and a friction sleeve inside which the mole body rotates is recommended Such a sleeve can reduce the overall friction by up to 90 Benefits v Mole may be launched from the surface or from a pit v Steerable method Can be steered around obstructions v Low operational costs v Quick system v Noise and traffic disruption less than conventional trenching Drawbacks x Only for small diameters x Can only be used in compactable soils x Ground investigation essential C 3 2 2 5 Pipe
151. rvice restored Benefits v Sealing technique v surface damage is produced No dig required v Suitable for no man entry sewers v Very low social cost as few traffic disturbances noise or dust produced v Very quick total working time compared to digging methods Drawbacks Non structural technique Possibility of environmental damage if grouting chemical material in sensitive zone x Many security and health measures to be observed x Difficult to measure in the project if voids surveying with radar has not been done C 1 2 4 5 Compacted filling Compacted filling is an auxiliary work for some dig operations It consist in compacting the back filling in trenches or gaps In sewer repair framework compacted filling is usually referred to small dimension holes or gaps in which soil may already exists but it s not enough compacted Compacted filling known Spanish as retacado has some differences with standard compacting 33 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Sewers constructed in large depths more than 6 8m were often dug by mining technique today newer trenchless techniques have displaced this method During sewer mining soil upwards the vault and behind the walls should be compacted filling to avoid gapping between soil and sewer vault and walls This gaps may cause sewer pathologies in the case that the sewer work in pressure because internal over pressure is sup
152. s are normally required to accommodate the replacement of pipe sections Ground surface heaving can occur if the depth of cover is too little or soil is un compacted All sewer services must be excavated before bursting and reconnected to the new sewer afterward C 3 2 1 9 Pipe ejection modified pipe jacking Pipe ejection or modified pipe jacking is a pipe replacement system in which the unbroken existing pipe is removed from the ground while the new pipe is simultaneously installed The old pipe is broken into pieces only as it completely exits out of the ground This techniques are applicable only for pipes with sufficient remaining thrust capacity to withstand the push forces They are used on shorter replacement sections to avoid high frictional resistance In pipe ejection the replacement pipe pushes out the old pipe A jacking frame is placed into the insertion pit as well as the replacement pipe which is installed in segments The jacking frame and the insertion pit are sized to fit the length of individual pipe segments Process Excavation of the bore is carried out from the jacking shield which consists of a steel cylinder Excavation can be carried out by hand mechanical excavators or remote controlled tunneling shields new pipe is placed against the old pipe and as the new pipe is jacked the old pipe is pushed toward a reception pit or manhole At the reception pit the existing pipe is
153. s only suitable for water mains of 600 mm diameter or greater x The application of the cement mortar requires a completely cleaned and dried pipe Cross section decreases slightly Access to customer homes and businesses is required to isolate every water service line and to apply compressed air to clear the service connections after the lining process Control of infiltration required Epoxies and Polyurethane resin require curing time Sewer surface needs to be carefully prepared to ensure bonding Deformation of existing pipe can cause problems Many security and health measures to be observed High level of operator skill C 2 2 1 3 Fibers reinforced cement mortar spray Manufacturers of reinforced cement or epoxy liners include fiber reinforced mortar calcium aluminum mortar polypropylene or glass reinforced The diverse fibers listed above are mixed with mortar in very low percentages changing significantly the properties of the mortar Workability flexion and compression resistance elastic module and other mechanical proprieties are modulated by the percentage and kind of fibers added Process 38 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Process can be man made or robot made and follows basically the same scheme than steel reinforced cement mortar spray bit in this case steel reinforced is not used Benefits v Fibers added to mortar can change i
154. se the new conduit is on a different line off line or because the technique damages the connection points that must be reconstructed e g pipebursting In these cases there are no many options for reconnecting but digging The chart and the database inform about this condition D 2 2 8 Requires later re opening of laterals connections This characteristic that could appear as redundant comparing to Need of digging for reconnecting laterals provides a significant new note regarding reconnecting laterals operations In this case it s studied if the rehabilitation technology blocks out the lateral connections or not If it does not then no further operation is required to accomplish the rehabilitation works If the technique blocks the connections then a later task of reopening them is required As explained before this reopening can be hand made robotic or digging This makes extra charges and time consumption that must be considered for direct and indirect cost calculation D 2 2 9 Possibility of work interruption It s convenient to know if the works during a rehabilitation can be stopped because there are several external agents that may affect them Other activities in the same location of the project may make more attractive a technique that gives the possibility of being temporally interrupted 88 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE D 2 2 10 Requires man in underground Unfortunately ac
155. sion gaskets are assembled together to form a pipe This pipe may be made in a circle or other shape as required The tunnel is constructed by repeatedly connecting these segments together to make the next pipe in the tunnel Before the next pipe in the tunnel is made hydraulic cylinders push against the last pipe installed and advance the tunnel shield through the ground After the tunnel shield is advanced the hydraulic cylinders are retracted and the next set of pipe segments installed to make the next pipe The process is then repeated After the pipe in the tunnel is installed the annulus is grouted Benefits v Mini tunnels can be installed in most types of ground conditions v Loads on the pipe are reduced because the soil above the pipe is not disturbed 71 COMPUTER DED REHABILITATION OF SEWER NETWORKS Small access shafts can be used 4m of diameter pit which reduces disruption at the surface v House connections can be re connected during the construction phase v After the tunnel is installed the tunnel shield can be taken apart and removed from the tunnel a reception shaft is not necessary for all installations v All work is measured and checked by a laser The precision of the tunnel installation is 1 cm v Reinforced concrete segments not always required because the construction method significantly reduce the stress on the pipeline segments v Curved bores can be produced v Line and leve
156. sisi sconsessecessconsconsatsscenscdonstnncanesannsdencenssvenaseaissevenene 15 C REHABILITATION TECHNIQUES REPAIR TECHNIQUES 17 DIGTECHNOLOGIES p E 17 CILLI Open 0116 TE 17 C LLLI 17 C 1 1 2 Semi Open C t 18 C 1 1 2 1 Shoring and Trench box modificated 0 sss 18 C1122 Concrete sheet rE E E EE 19 2 3 566010116 20 TRENCHLESS TECHNOLOGY 21 12241 EobotcTepalrs eiie it 21 C 1 2 1 1 Injection in joints Cracks 21 C1212 Milling 22 C 1 2 1 3 Rootcutting 23 0110118 Ec 23 12 1 6010110111 eese a dide MED HA UU HE pU ede 24 121 222 Short liners 25 C T2 HI Fiberglass dnd pol yHIBE Sae oinnes eir neus 25 1 222 rc M 25 L2 3 Manmade tepals 26 C1231 Masonry
157. ssccsescescecescsssessceseseseseseeceasdseecsesesececacesesesesosescsesdsesesssess 11 THIS DOCUMENT weissssccisccssccscccsacccsccssccccccsscc scesscccccessccssocseccsccessec scesscescesseccs ccsssecs 12 B OBJECTIVES 13 B 1 REPORT D12 OBJECTIVES 13 B 2 PROCESS AND METHODOLOGY ccccscscscscssscscscscscccccccccccccccscccccccccccccscscscscccsescseses 14 REHABILITATION TECHNIQUES ccccssssssssccccccccccesscccccccccccccescsccccccccecesescccccccsceeces 15 C REHABILITATION TECHNIQUES 1 17 C 2 RENOVATION 5 255 36 C 3 REPLACEMENT 55 UPMME OH MEME 51 CA MANHOLE REHABILITATION 76 C 5 LATERAL CONNECTIONS REHABILITATION ccssssscssssssscccssssccccessscsccssssssscssssseces 77 D REHABILITATION TECHNIQUES CHART D 1 RT CHART DESCRIPTION cccccccccssssssssssssccsscssssscscsssccsccsssssoscssscscesssssscsosessssesees 79 0 2 COLUMNS CHARACTERISTICS cccscccscssssssscscscccccccccccscccccccscccccccscccscccscccscccscceses 79 E REHABILITATION TECHNIQUES DATA BASE E 1 RT DATA BASE DESCRIPTION cccccssssssssccccccccccccessccccccccccccsescsccsccc
158. t all the sizes diameters are available in all the regions The measures here exposed are intended to be the extreme values of the European market It must be advised that the development of the rehabilitation techniques market is quick and presented values may not be always updated in some cases When this characteristic is marked as min or max it means that the applicability of the technique is independent of the minimum maximum size of the sewer 1600mm has been establish as the minimum size for man entry sewers and consequently all the man made repairs mark this size as minimum Other local regulations more restrictive or permissive about working in confined spaces should be implemented by the end user to better adjustment of suitable man made technologies This can be done easily in the Rehabilitation Technology Data Base Regarding replacement techniques they are not influenced by the diameter of the existing sewer In these cases this value indicates the sizes the technique can achieve diameter size of the new sewer D 2 1 4 Shape and visitability of existing sewer Four categories have been distinguished circular non circular man entry no man entry All the techniques are suitable for circular pipes but some of them cannot adapt to rectangular or ovoid sewers or with vault As this kind of sections is quite usual in many locations this is a decisive characteristic to be included in applicability conditions
159. t in the ground v Noise and traffic disruption less than conventional trenching Drawbacks x Pipes with significant structural damages are not adequate for this method because pipes must have enough remaining thrust capacity to withstand the pull forces x Thorough site investigation required x M High level of operator skill C 3 2 1 41 Pipe pulling Pipe pulling is a method of replacing small diameter service pipes by attaching a new pipe to it and pulling it through the ground This technique is particularly appropriate for lead service pipes The new pipe is attached to the existing pipe which is pulled through Process method utilizes a winch cable fitted with a metal cone that grips the internal wall of the old pipe Some systems have a series of cones to distribute the pulling force along the length of the pipe replacement pipe is attached to this end of the cable allowing it to be pulled in place as the old pipe is removed pulling device that provides the force to pull the old pipe out of the ground is a winch attached to the other end of the cable Benefits v Replacement pipe can be PVC or PE v Only pit damage done in surface pavement v fragments from the old pipe are left in the ground v Quick system v Noise and traffic disruption less than conventional trenching Drawbacks x Only suitable in very small diameters up to 25 mm x small diameters of the service pi
160. table ground conditions v The method is applicable in deep sewer installations Drawbacks x High costs High level operator experience is needed Tunneling needs a minimum depth of cover A tail tunnel is required for effective spoil removal full tunneling It is expensive for short stretches Extensive geotechnical information is required Potential exists for ground settlement Many security and health measures to be observed X 75 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE C 4 Manhole rehabilitation Man holes are the chambers with removable cover constructed on a drain or sewer to permit entry by personnel EN 752 1 Manhole rehabilitation technologies Dig technologies Preformed manhole units Concrete liners poured in place Liners Cured in place pipe soft reversion lining Cementious coatings Sprayed pumped or troweled Polymer coatings Sprayed pumped or troweled Cementious grouts Polymer grouts Mechanical seals or inserts Protective systems for new manholes 76 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE C 5 Lateral connections rehabilitation Lateral connections are understood to be the pipes that lead the wasted waters from the particular buildings to the public sewer as well as the connection itself Techniques for these pipes rehabilitation are the same than for sewer rehabilitation only limited by the minimum siz
161. ted for the bursting head If the existing pipe is deviated to the extent that a straight axis through the pipe lies partly outside the pipe special rods equipped with cutting edges along their length are combined with standard rods to make a steel rod string The rod string is positioned at correct line and grade in insertion and receiving pits but is forced into a curved shape to accommodate line deviation When the rod string is anchored in tension rods with cutting edges press against the inside wall of the sewer pipe under the crown in the case of sag The rod string is then rotated forcing the cutting edges to cut through the existing pipe wall and surrounding ground until the rod string is straightened out at the desired correct line and grade 55 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Benefits This method is recommended where grade is critical Able to correct sags humps and misalignments Slurry fills voids and other defects increasing the structural strength of the pipe Cleaning of the existing pipe is not necessary Existing manholes can be used as launch pits A larger diameter pipe can be inserted NN 4545 Drawbacks x excavations are normally required to accommodate the replacement of pipe sections x Ground surface heaving can occur if the depth of cover is too little or soil is un compacted x All sewer services must be excavated before bursting and reconnected to the new sewer
162. ting head forward The head is pulled by either a pulling rod assembly TRS system or a winch cable which is inserted through the existing pipe and attached to the front of the bursting head The tensile force applied to the bursting head is significant The cone shaped bursting head transfers this horizontal pulling force into a radial force which breaks the old pipe and provides a space for the new pipe If a rod assembly is used for pulling the bursting process is done in consecutive sequences rather than continuously Prior to bursting the segmented rods are inserted into the old pipe from the reception pit The rods are not very long and during insertion they are threaded together to reach the bursting head at the insertion pit There they are attached to the front end of the bursting head and the new pipe is connected to its rear end In each sequence during the 54 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE bursting the hydraulic unit in the reception pit pulls the rods for the length of individual rods and the rods are separated from the rest of rod assembly as they reach the reception pit If a winch cable is used instead of rods the pulling process can be continuous However a typical cable system does not transmit as a large pulling force to the bursting head as a rod assembly Benefits Very few vibrations Drawbacks x Lower bursting power C 3 2 1 4 Controlled line and grade system CLG
163. to ensure good adhesion Systems are typically modified to provide some level of structural integrity A variety of modifications can be made to cement to increase the mechanical properties and hence increase the structural capability of the coating Process ferrocement sewer is cleaned and dried Connections temporarily cut Sometimes a preliminary task of demolition and extraction of damaged elements is necessary Layers of steel mesh are fixed to the existing pipe wall Mortar is applied over and through the mesh gunite operation Ahigh strength liner that resist the growth of cracks is formed f smooth roughness required a manual process of finishing up be done in man entry Sewers Benefits Can offer structural reinforcement Sealing technique Variations in cross section easily accommodated Lateral connections relatively easy to handle Live flows can be negotiated in some cases No surface damage is produced No dig required Very low social cost as few traffic disturbances noise or dust produced Fast installation times NN A lt Drawbacks x Only suitable for man entry sewers x Sewer surface needs to be carefully prepared to ensure bonding x Cross section decreases slightly steel reinforcement plus mortar gunite can make 2 3cm thick x Control of infiltration required x Many security and health measures to be observed x High level of operator skill 8 Metho
164. to remark that the rehabilitation methods are presented under their technical names meanwhile commercial names have not been listed in this document This pretends to aggregate in a single name all the techniques that under different commercial names that may vary even from country to country are in fact the same technique although sometimes they might present slight variations All rehabilitation methods found after literature and contractors survey are exposed in the document A few of them are not fitted for sewerage but they are still presented to provide a complete state of the art in rehabilitation technologies that it is also useful for other CityNet projects 13 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE B 2 Process and methodology The process of elaboration of this document and the tasks linked to it RTs chart and RTsDB by WP4 partners can be summarized in the following steps gt gt Elaboration of a list of RTs separated according European Standard EN 752 5 1997 Drain and sewer systems outside buildings in repair renovation and replacement Searching for techniques and creation of sub categories to gather them into uniform groups As it has been mentioned above a literature survey was made but most information was found in internet Simultaneously to this searching a list of valuable characteristics for RTs was elaborated with the cooperation of WP4 partners For this second list it
165. top This material is usually selected soil sand or concrete The lengths of pipes are assembled in joints Replacement of lateral connections if necessary are made and sealed trench is back filled and compacted in layers if granulate material employed or with concrete to ensure adequate support around the pipe Finally the surface pavement is reinstated Benefits Low level of operator skill required Suitable for all pipe materials Ability to overcome unknown obstructions Other infrastructure can be rehabilitated or replaced at the same time allowing for coordination of work and sharing of costs 17 COMPUTER AI DED REHABILITATION OF SEWER NETWORKS CARE Drawbacks x The cost of the open cut method can be substantial compared to some newer technologies x Construction is usually longer than with most trenchless technologies due to the quantity of disturbance to other infrastructure and traffic and the amount of reinstatement work required following the installation of the sewer x There are more safety concerns due to traffic issues on road rights of way the number of excavations required and the large equipment needed to perform the work x There can be disturbances to other surface and buried infrastructure x The social and economic costs of major open cut projects can be substantial during construction x Large volumes of earth works required high transport costs x Risk of l
166. ts proprieties to accommodate to each project requirements Semi structural and non structural applications Sealing technique Variations in cross section easily accommodated Most cement mortar lining equipment can accommodate small bends No surface damage is produced No dig required Very low social cost as few traffic disturbances noise or dust produced Fast installation times Drawbacks x The application of the cement mortar requires a completely cleaned dried pipe Cross section decreases slightly x Sewer surface needs to be carefully prepared to ensure bonding Many security and health measures to be observed in man entry sewers High level of operator skill C 2 2 1 4 Polymer lining Application of a lining or coating by either a rotating head which is winched through the pipeline or hand held spraying equipment which is used for lining sewer lengths and or manholes Materials usually sprayed to the inside walls are epoxy or polyurethane Process pipeline is cleaned to remove encrustation and protrusions Inspection of the main is carried out to ensure no infiltration and a relatively clean surface for adhesion of the coating The host pipe must not have any pinholes or other possible leaks in the pipe wall two component resin is mixed under specified conditions and pumped though lines to a spinner head The appropriate mixture and temperature of the resin and
167. uality control of materials and or constructive methods usually these periods happened to meet after wars gt sewer material low quality materials usually linked post war periods present a shorter lifetime than quality controlled materials in particular concrete is quite sensitive to this issue and gt constructive methods that carry associated trends to present some particular defects as e g mining may lead to vault fissuring when soil over vault has not been well compacted and pipe works in pressure in rain events As external causes it can be mentioned the traffic overloads that may cause structural damages in shallow sewers soil overloads that may cause damages in deep and not properly designed sewers root intrusion that causes partial or total blockages as well as fissuring or joint displacement mines war shelters and tunnels that change the soil stress state other buried services that may affect directly to sewers piercing them partially causing blockages and hydraulic capacity decreasing kind of surrounding soil that may be chemically aggressive to some sewer materials watertable that may cause several problems in pipes under it and drinking water network spills that may wash out soil around pipes and also inflow in sewer network causing different problems These causes of internal and external damages lead to diverse pathologies like fissures cracks deformations infiltrations exfiltrations
168. ually prior to grouting of the annular gap Panel or section insert liners are used only where person entry to the sewer is available When panels are used they are designed to form a close fit with fixed spacers then grouted in place The panels are relatively light and are designed to pass through access holes Larger diameter sewers can be lined with sections rather than panels These would be carried into the pipe and joined in situ The sections should also be grouted in place Process The process is the same than for man entry sliplining Lateral connections are disconnected ndividual lining units are passed into the pipeline via manholes or special access shafts Lining begins from furthermost point Units are positioned and joined Small section lined then grouted before proceeding to next section 45 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Benefits v These technologies can be applied for structural or non structural purposes v liner can be designed to match the original host pipe diameter thereby minimizing the loss in capacity v The liner can be effectively laid to a required grade as individual pipes can be fixed within the host pipe by spacers v Sections easily cut to form connections v There is reduced infiltration v There is minimal disruption at the surface as access can take place from existing manholes Drawbacks x Bypass pumping is required x Itis a la
169. ufficient confining pressure is reached Compressed air has also been used successfully in some projects to support the working face of the shield but this technique is essentially limited to the less pervious categories of soils Additional improvements have been made to the shield tunneling technique over the most recent years particularly in terms of machine size and ground motion control Large Tunnel Boring Machines TBM are now common and shields with diameters up to 14 m and over have been manufactured for projects These advances have allowed the shield technique to be extended to a larger scope of project conditions including motorway tunnels that currently require openings in the order of 12 m to be excavated Such advances have been accompanied with significant technological improvements that allow a more appropriate management of adverse conditions to be obtained when tunneling in difficult grounds The introduction of foams in EPB shields allows a more appropriate control to be achieved of ground deformations at the working face and in turn of tunneling induced settlements Similarly large diameter TBMs can be equipped with a secondary internal cutting wheel to help excavate through sticky clays The introduction of advanced back filling processes at the shield tailpiece has also strongly contributed to significantly reduce the potential for tunneling induced settlements in providing a means for limiting the amount of ground movement
170. ult values depending on the characteristics of the analysed network and of catchment The user can also modify or add single information to the pipe characteristics spreadsheet before running the cost tool D c v xa a 1 v S 600 300 1 2 3 5 10 Yes No City Street No 600 12 Figure 3 The default values table 103 COMPUTER AI DED REHABILITATION OF SEWER NETWORKS CARE F 3 4 Result presentation After entering the available pipe data and the default values the user has to click on the computation button the calculator in the toolbar in figure 1 and the results should be written in the RT_costs spreadsheet in form of the following table figure 4 4 1 Em 1 1 Rehab Rehab PIPEID Rehab ID Rehab Techology cost 1 cost 2 j 01141 conventional trench 72000 108000 j 0111 shoring and trench box 135000 202500 8 concrete sheet pile single 153860 230790 1 1001 1 2 1 2 milling robot 600000 900000 1001 12 1 3 root cutting robot 6000 9000 1001 1 2 3 1 masonry 28274 42411 10011234 injection 138600 207900 j 1001 1236 pre cast repair 54000 81000 j 10011242 mortar stabilization 138600 207900 j 1 conventional trench 48000 72000 j 1002 1 1 2 1 shoring and trench box 111000 166500 1002 1 1 2 2a concrete sheet pile single 153860 230790 1002 1 2 1 2 milling robot 600000 900000 1002 1 2 1 3 root cutting robot 6000 9000 j 10021231 masonry 42410 63615 10021234 injection 207900
171. ulticriteria decision support WP7 Wastewater network rehabilitation manager WP8 End user testing WP9 Dissemination WP10 Administration A 2 Work Package 4 CLABSA leaders WP4 which summarized objectives are General survey of available techniques and contractors Require information from international associations of trenchless technology Analysis of experiences and results Build a complete chart for the variety of methods in rehabilitation of sewers Current state of the art Rates range of applicability limits and restrictions Combine global and local approach Evaluate cost of rehabilitation linked to the applied technology Approach to some formulae of cost calculation Present other valid alternatives for rehabilitation redesign of sewers operational methods Criteria for choice making of suitable techniques related to sewer problems To complete the criteria for wastewater network management this work package will present appropriate measures to tackle various wastewater network problems There are a variety of methods to rehabilitate wastewater networks The method to be chosen obviously depends on local conditions such as the type of the problem the size of the pipe etc The rehabilitation costs are linked to the applied method and technology Two specific tasks have been defined 11 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE Operational options Task 4 1 Some functional problems
172. umns The cells were filled with the contribution of WP4 partners D 2 Columns Characteristics Characteristics of the RTs have been divided in clusters identifying clearly those characteristics that are decisive for the election of the technique fron those that give useful but not decisive information Groups are D 2 1 Applicability conditions or requirements Under this area it has been listed characteristics of the technique that make it suitable or not to solve a determinate problem in the sewerage network These characteristics deals with the technique ability to cope with a sewer defect the size shape materials working constrictions and others that may reject the RT These characteristics are used by Multicriteria Decision System to offer the end user only the Rts that are suitable to solve its particular problem before ranking them Applicability conditions fields are D 2 1 1 Kind of defect solved Obviously one of the most important characteristics of a technique in order to decide about its suitability is if it can solve the sewer defect appropriately To achieve this purpose possible defects in sewers have been classified according to standard EN 13508 2 Condition of drain amp sewer systems outside buildings Visual Inspection coding system 79 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE The defects considered in the chart are e Related to the fabric of the pipeline deformation BA
173. unding soil as spoil is systematically removed Systems are generally un steerable therefore best suited to cohesive or stable soils There are two types of auger boring track type and cradle type The track type method consists of a track system machine casing pipe cutting head and augers The boring operation is cyclic as pipe segments and auger flights are added after a prescribed auger flight length is installed Thrust is developed by hydraulic rams located at the rear of the boring machine One end attaches to the end of the boring machine while the other attaches to lugs connected to the track system No rotation is applied to the casing as it is jacked through the soil by hydraulic thrust rams located at the rear of the machine Lubrication is used to reduce skin friction and to aid with soil cutting and transport An additional common measure to reduce skin friction includes an over excavation in the order of 25 mm to 50 mm Pipe diameters range from 200 mm to 1200 mm and overall installation lengths are typically limited to 100 m 65 COMPUTER Al DED REHABILITATION OF SEWER NETWORKS CARE In the cradle type auger boring method the boring machine and the complete casing auger system are held in suspension by construction equipment i e side booms excavators or cranes as the boring operation is executed There is no requirement for any thrust structures however the entire casing length must be assembled outside the launching
174. was discussed the information that was convenient to know from the RTs Three categories were made to point the importance and content of the characteristics applicability conditions or requirements technology performance characteristics and environmental impact and comments As it ll be explained in detail in Part D the first group of characteristics gather the characteristics that make a RT able or not to solve a defective sewer The other two groups give general and useful but not decisive information about the characteristics of each RT For each characteristic a first proposal of the output information was made ranges y n 9o high medium low etc With these elements the chart was constructed putting the RTs in rows and the characteristics in columns The cells were filled with the contribution of WP4 partners Next step was to export all this information into a data base RTSDB It was agreed for better integration with the rest of CARE S tools to do it in MS Access The RT Chart and the RTsDB follow the same scheme of information presentation It was also implemented in this data base a searching system that allow as it will be explained in Part E searching through applicability conditions Swindon meeting gave a new boost to this task allowing an interchange of ideas needs and requirements The implementation of a color code to the RT Chart and the checking of all the characteristics meanings as well as its related category ma
175. y useful information for ranking the techniques as gives parameters that allow calculation of important data as for example an estimation of work duration the requirement of auxiliary works etc D 2 2 1 Maximum length from each location This parameter provides an estimation of the maximum length of sewer that each technology is able to rehabilitate from one single working location usually a manhole or an access pit This gives an idea of the number of working locations required in works of special length Value is given in meters and measured only in one direction from the location i e downstream or upstream As rehabilitation techniques works are generally independent of the sense direction in most cases the length of pipe able to be rehabilitated from one location is the double of the maximum length from each location given value Results presented are estimation and different manufacturers may provide different values Even more the same rehabilitation technique may vary and usually do the working length depending on the pipe diameter bigger diameter shorter length This is marked in the chart with a value in parenthesis Some repair techniques affect very short lengths and in consequence a minimum length of one meter has been imputed On the other side rehabilitation methods with virtually no technical limitation as for example trenching methods or man made repairs have been catalogued as unlimited that should be un

Wastewater rehabilitation technology survey

Contents

Download Pdf Manuals

Related Search

Related Contents