Home

Slope Oasys GEO Suite for Windows

Contents

1. Partial Factors 12 Specify any reinforcement via Reinforcement 13 Enter any surface loads via Surface Loads 14 Analyse the data Warning error messages are shown ifthe Analysis data are inconsistent 15 After analysis the Print Selection Dialog will be displayed if Tabular Output analysis is successful Click OK to see the Tabular Output 16 The Graphical Output View gives a graphical representation of Graphical View the strata water levels slips and grid centres and their results Methods of Analysis General The methods of analysis available in Slope are as follows Swedish Fellenius Bishop Horizontal Interslice Forces Parallel Inclined Interslice Forces Spencer s Method Variably Inclined Interslice Forces Janbu Horizontal Interslice Forces Parallel Inclined Interslice Forces Variably Inclined Interslice Forces All these methods of analysis use the method of slices to determine the factors of safety for slope stability The detailed derivation for each solution is given in the individual references Oasys Ltd 2015 Slope Oasys GEO Suite for Windows 3 2 Theory of Slices The following provides details of the basic annotation and sign convention for the method of slices All forces are given as total forces i e including water pressure F Factor of Safety Ph Horizontal component of external loads Pv Vertical component of external loads E Horizontal Interslice Forc
2. EE 37 ASA RUN AlUC EE 38 4 3 7 5 Submerged SIOPS ze sets esescescceciecslivecesssadsidescbieesetseusechssedeaneduassasitvetescesgessaidesaessfususedeeesbiesdataesdeattes 38 43 8 Biezotmeterg e SES 39 CET CC SEN A0 KNUET Ge DOT 42 4 33 10 1 Circular Slip Zutate egecbrsger igeeerkeegdeege steeds NEESS 42 4 3 10 2 Definition of Gircl Centre Sinsen E N 43 4 3 10 3 Definition of the Cirele Radijs niri e cee a vine ane ain dE Ata 43 4 3 10 4 Non circular SlipS psies Are apao ies ENS E aee erines 45 AS TISUrtaGe E o To EE 47 Ge a A ee atoa E A T E T A E T E TT 48 KENEIgIOSZCTT LE 50 4 3 13 1 _Entering new graphical data eegtderdedueuteue dikes a eete anoe eaa araia Naat 50 A 31S 2 Inserting BIMADS EE 52 43 133 Strata Graphical input 2c 1 5 ncaa nie ia ny inven EE Eder nee eee EE 54 4 3 13 3 1 Defining Multiple Stratas sraa ira e E LEE AE EEE ENE EEIE E 56 4 3 13 3 2 Inserting a lens or w edge of Material ee eeecseceesecseesseeceeeeeecseeeaeeseessaessaesseesnesseeseesseeeseeeaeteaeeaes 57 4 3 13 4 Co ordinates of the w ater table Graphical mput eee eres sees sence tete sete eeeeeel 59 4 3 13 4 1 Water filled tension cracks 4 3 13 5 Non circularSlip tee eege eege Ee an 4 3 13 6 Importing DXF Data EE 5 Analysis and Results 64 5 1 Analysis and Data Checking cccceececeeeeeeeeeeeee ee eeeeee ee eeeeee se eeeeeeseeeaeeeseeeeeeeseeeeeeeseeeaeeeseeeaees 64 DZ SRE SUITS OUT DUE geseet e A A E ee 65 EKAN
3. Editing surfaces To edit the location of a point 1 Select the required phreatic surface on which to edit points from the Stratum dropdown box 2 Place the cursor over the point and click the right button This brings up an editing box as shown Coordinates x coordinate m 20 y coordinate m 8 2 Amend the co ordinates as required and then click OK Note Points can be deleted by placing the cursor over the required point and clicking the left mouse button at the same time as holding down the Shift key on the keyboard 4 3 13 4 1 Water filled tension cracks A water filled tension crack can be modelled by defining the position of the crack as part of the surface geometry of the section Stratum 1 The water level must then be set above the tip of the crack as shown Oasys Ltd 2015 ER Slope Oasys GEO Suite for Windows ground level 7 phreatic surface en v eeeee tet actual surface Ww common paint of slip circle input surface Ee of tension crack MK D slip circle The slip surface to be analysed in such a case typically passes through the tip of the crack Bearing in mind the possibility of rounding errors it is best to set the common point of the circle slightly above the tip of the crack as shown To avoid analysing circles which happen to pass through the material on the other side of the crack it is advisable to lower the ground surface on the outside of the crack a
4. The suction at the phreatic surface is zero The value of suction will then increase using a linear hydrostatic profile to the specified maximum height h The soil suction is then held at the constant maximum value above this level Suction Maximum Naus S Phreatic Surface Hydrostatic Profile Note Ns is positive and expressed in units of head of water The effect of soil suction on the area of the slip surface above the phreatic surface is as follows Slope calculates the negative pore pressure which is equal to the height of the slip surface above the phreatic surface i e distance AB Oasys Ltd 2015 ER Slope Oasys GEO Suite for Windows 4 3 7 4 4 3 7 5 Ground level negatve ss phreatic surface o m e Em PT T digi If the slip surface is above the maximum height h then the suction is assumed to be constant and equal to h Note If no suction is specified the program assumes zero pore pressures above the phreatic surface Ru Value In the absence of detailed information about the position of the phreatic surface pore pressures on the slip surface may be expressed in terms of a single Ru value Where Ru Pore Pressure Total Overburden Pressure In this case the program calculates the pore pressure u at each point according to the equation u pRu where p is the total overburden pressure Submerged Slopes For a submerged slope the phreatic surface is located a
5. Reinforcement Graphical Input Output Tabular Output Graphical Output Factors of Safety Seale x 1 417 y 1 417 Tableview The following graphical displays are available and can be displayed or hidden by toggling the individual icons on the graphical menu bar HE Axis Provides a reference grid behind the drawing Set Scale This allows the user to toggle between the default best fit scale and the closest available engineering scale e g 1 200 1 250 1 500 1 1000 1 1250 1 2500 RH Save Metafile this save icon allows the file to be saved in the format of a Windows Metafile This retains the viewed scale The metafile can be imported into other programs such as word processors spreadsheets and drawing packages omp Bitmap This allows the user to insert a bitmap behind the main graphic on the Graphical Output screen X Zoom Facility Select an area to zoom in to by using the mouse to click on a point on the drawing and then dragging the box outwards to select the area to be viewed The program will automatically scale the new view The original Oasys Ltd 2015 Slope Oasys GEO Suite for Windows 5 3 1 1 area can be restored by clicking on the restore zoom icon as shown here A Strata Switches between showing the material layers as solid fill or as lines es RE Hatched water or Dashed water Shows either a shaded area corresponding to the saturated zones of soil or the locati
6. Company info The company information button in the preferences dialog box allows external companies to specify the bitmap and Company name that they would like to appear the top of the printed output Oasys Ltd 2015 4 Slope Oasys GEO Suite for Windows Company Information Enter the full path of the bitmap file that you would like to appear on your printed output The bitmap will be fitted into a space approximately 4 cm by 1 em but its aspect ratio will be maintained Select the company name that you would like to appear lt blank gt on your printed output To add a bitmap enter the full path of the file The bitmap will appear fitted into a space approximately 4cm by 1cm The aspect ratio will be maintained Note For internal Arup versions of the program the bitmap option is not available Page Setup Opens the Page Setup dialog allowing the style of output for printed text and graphics to be selected If Calculation Sheet Layout is selected the page is formatted as a calculation sheet with details inserted in the page header If Logo is selected the company logo is inserted in the top left corner of the page If Border is selected this gives a border but no header information If Clipped is selected the output is clipped leaving a space for the logo This has no effect on text output 2 Step by Step Guide The following provides a comprehensive guide through the menu options to help ne
7. Horizontal Interslice Forces Parallel Inclined Interslice Forces Spencer s Method Variably Inclined Interslice Forces Janbu Horizontal Interslice Forces Parallel Inclined Interslice Forces Variably Inclined Interslice Forces Factor of Safety The factor of safety can be applied to the soil shear strength or the applied loads Partial Factor Analysis The Over Design Factor can be calculated for an ultimate limit state partial factor set Minimum Number of Slices Oasys Ltd 2015 Slope Oasys GEO Suite for Windows 4 3 4 1 4 3 4 2 4 3 4 3 The program requires the minimum number of slices for each slip surface to be specified The default value is 10 Maximum Number of Iterations All the methods of solution except the Swedish Circle method iterate to reach a solution The program defaults to 100 iterations but the user can specify any number Reinforcement Active Unchecking this box allows reinforcement data to be omitted from the calculations without having to remove the data Soil Nail Analysis These options allow the user to specify the method for calculating the bond stress and restoring moment attributable to soil nails Details of the analysis options are included in the Reinforcement Calculations section Factor of Safety on Shear Strength If this option is specified the program divides the shear strength parameters c and tan A of each soil stratum by a factor of safety The program then iterates
8. Slope file Strata Graphical input When entering stratum coordinates ground level should be defined at Stratum 1 with the soil layers below entered in order as Stratum 2 3 etc Select Data Strata or the strata button Es from the graphical input toolbar if the graphical input view is already open Oasys Ltd 2015 Input Data 55 Slope 19 0 SLOPEman sld Graphical Input Ca File Edit View Data Analysis Tools Graphics Window Help DPM XOGSRleGQev vozx L Ge om Aa oA XAA iw 4 eet ATS te a d x 20 00 y 17 91 Stratum Stratum 1 Assigned material Made Ground v DEER h teeter tt teehee Peete EE kk kk kA kk Ak Sandd hb wb aber ee zb de d a mm mr eee ee eee lie mr mi H 000 8 000 20 00 Scale x 1 361 y 1 361 For Help press F1 Tableview NUM Strata window Adding strata The procedure for entry of a new stratum is as follows 2 Select lt New Stratum gt from the Stratum dropdown box at the top of the window x y Stratum Stratum 1 v Assigned material Made Ground v Stratum 1 Stratum 2 Stratum 3 Stratum 4 Stratum 5 lt New Stratum gt 2 Select the correct Soil name from the Assigned material dropdown box at the top of the window Oasys Ltd 2015 ER Slope Oasys GEO Suite for Windows Assigned material v Made Ground Gand Clay Sand Lens 3 Place the cursor at the location of a point which you wish to define a
9. change in gradient of a stratum at each slip surface stratum intersection at each slip surface phreatic surface intersection at the mid point of a slice whose width is greater than the average slice width given by Xignt 7 Xer Minimum number of slices 3 3 Swedish Circle Method Fellenius This method is applicable to circular slips but may not be used for submerged slopes or where there are horizontal surface loads Assumptions 1 The method assumes that for each slice the resultant of the interslice forces is zero The forces are resolved on each slice parallel to the base i e Ia g Xaa 0 and E 7 E 0 2 The method satisfies overall moment equilibrium Oasys Ltd 2015 Methods of Analysis 1 1 B F SH _ Restoring Moment mer DREI TE EE DEES e Eer ZIW Py x Dal Disturbing Moment Where S cL N uL tan P W P X X cos a E E4 P sin a For undrained materials where p 0 this method of analysis gives identical results to Bishop s Simplified method For drained frictional c materials the assumed force distribution does not satisfy conditions of overall horizontal or vertical equilibrium The factors of safety therefore usually fall below the lower bound values obtained from solutions which do satisfy statics The above assumptions do not satisfy Newton s principle of action equals reaction between adjacent slices The errors although on the safe side can be larg
10. d Data pp eessen 24 QSisTitles 9 gt 4 tiikiecdestiiaken ee a ae ea ee ee ee ad 26 Lt Titles Window tree eege Ee dee SEA 27 4 3 2 Units ene a a thee eee EE 27 Oasys Ltd 2015 Contents 1 4 3 3 General Parameters crniiin A ea aa a Ea Aan ia aada aaa aa aa araa aa la E Sa vovse satsededeeuteatgetenace 28 4 3 4 Analysis Method sssscsssssssssssssscsssssssssassssseseansesssseassesseneansesseseaeseeseaeaeseessaeaesesseaesessansaeaeseseaesesesneacsesseanaesesssseatass 29 4 3 4 1 Fa tor of Safety op Shear Strengths siiis vis eeceeect exseadeteedapvabentevecest escheat tasu OEEEEEEEEE EEN 30 4 3 4 2 Factor of Safety on Applied Loads rere seorierissierei in senaties eivind 30 ZA Distribute Suttace keete iis n a E R ee da in ee ee R 30 4 3 4 4 Partial Factor EE 31 4 3 5 Partial FaCtorS a ete SEENEN EENEG 31 4 3 6 Material Properties scccsssssssseesessesneeesensnenenensnenenensnensnenanenenensnenenenanenenensnensnensnensnenenensnenensnsnensnensnsnensnenenanen 32 Z Groundwater eege Seeerei 33 4 3 7 1 Groundw ater with Hydrostatic Pressure Distribution ceceesceeeeeeeeeeeeeeeeneeeeeeeeeteeeeeeeseeeeeeeaeteeeaee 34 4 3 7 2 Groundwater with Piezometric Pore Water Pressure DistriDUtiOn eeceeeeeseeeeeeeeeeeeeeeeeeeeeeeeeneeaee 35 4 3 7 2 1 Interpolation Of piezometer data scsi iets cece se ete cceseess vasteedeetantenen ees NEESS SEENEN vee 36 A 3 7 3 Soil Suctiony22
11. each slice A positive horizontal acceleration is assumed to be in the direction of the slip A negative acceleration opposes the slip The default value is zero This application is not relevant to the Swedish circle method Direction of Slip Movement Downhill The program examines each slip surface and sets the direction of movement to be downhill This is particularly relevant for the modelling of embankments where a full cross section is defined Increasing x This creates an anticlockwise slip Decreasing x This will create a clockwise slip Oasys Ltd 2015 Input Data 4 3 4 Analysis Method The Data Analysis Method menu command opens this dialog or it can be opened by clicking on the gateway The following analysis methods can be selected E D SLOPEman sld Analysis Method elle Analysis method Interslice forces Analysis option Swedish Horizontal FOS on Shear strength Bishop gt Parallel inclined D FOS on Disturbing surface loads SE Variably inclined D FOS on Restoring surface loads D Partial Factor Analysis Apply nail anchor force as a surface load KEEN Gier S Maximum iterations 100 Soil nail analysis Minimum slices 10 S Reinforcement active 2 Option 1 See Distribute surface loads Option 2 0 ption 3 Method for analysing nail bond strength Radial stress equal to vertical stress D Radial stress based on HA 68 94 es Und AD IM undo Swedish Fellenius Bishop
12. for Windows 4 3 1 Titles The first window to appear for entry of data into Slope is the Titles window FA SLoPEman Titles Job Number Initials Last Edit Date z ee 77101 60 L H E 26 Jun 200 Model Image Job Title Oasys Manual Example Subtitle Bishops Method Calc Heading Yariably Inclined Interslice Forces Notes Calculetion to show the main aspects of MLE BB paste X Remove Calculation to show the main aspects of Copy SLOPE including loads piezometric profiles and a grid of circle centres Written by Slope version 19 0 0 0dev This window allows entry of identification data for each program file The following fields are available Job Number allows entry of an identifying job number Initials for entry of the users initials Date this field is set by the program at the date the file is saved Job Title allows a single line for entry of the job title Subtitle allows a single line of additional job or calculation information Calculation Heading allows a single line for the main calculation heading The titles are reproduced in the title block at the head of all printed information for the calculations The fields should therefore be used to provide as many details as possible to identify the individual calculation runs An additional field for notes has also been included to allow the entry of a detailed description of the calcu
13. for moment equilibrium change to Oasys Ltd 2015 e Slope Oasys GEO Suite for Windows 3 2 1 1 S h y cosa xsinc Restoring moment IO P Necosa x P N sinc Disturbing moment rMo rMo For full details of notation see Theory of Slices Method of Iteration Slope uses iteration to reach convergence for each of the Bishop and Janbu methods as follows Factors of safety For each iteration i Slope calculates a new factor of safety F using the ratio of restoring moment to disturbing moment which is a function of F when the difference between F and F is within the specified tolerance the calculation is complete The factor of safety F is the ratio of restoring moment to disturbing moment However this ratio is itself a function of F except in the Swedish circle method so an iterative solution is necessary Horizontal interslice forces 1 Slope starts at slice 1 Note Slices are numbered from left to right and by maintaining vertical equilibrium it calculates the resultant horizontal force 2 The program then uses this as the interslice force with slice 2 The process continues until the last slice which ends up with a resultant horizontal force In this method each slice and the slope as a whole is in vertical equilibrium with zero vertical interslice forces Horizontal equilibrium is not achieved within each slice or the slope as a whole Therefore the only force check within each slice
14. model which has been defined Data Input All data is input via the Data menu or the Gateway File Edit View Analysis Tools Window Help Oasys Ltd 2015 Input Data 25 Units SLOPEman Gateway 5 Input General parameters Units Analysis options General Parameters Method Partial Factors Analysis options Method Partial Factors v Titles Titles v Materials Materials 4 v Groundwater ji Arouna Meer Single 4 Piezometers 3 Piezometers v Strata Original 4 v Slip surfaces Pe Serge tatum v Surface Loads Stratum 2 5 Reinforcement Stratum 3 4 Stratum 4 6 Graphical Input Stratum 5 6 Slip surfaces Surface loads 1 Reinforcement Graphical Input Output Tabular Output Graphical Output The information can generally be entered in any order Exceptions are that the material data must be entered before the strata It would also be advisable to enter groundwater and piezometer data before the strata so that the associated groundwater information is available for each stratum as it is entered Once data has been entered the program places a tick against that item in the menu list Graphical input allows the strata water table and any non circular slip coordinates to be drawn rather than entered as tabular input Data entered in the graphical view is shown in the tabular input and vice versa The following topics describe each of the menu items in detail Oasys Ltd 2015 ER Slope Oasys GEO Suite
15. select an area to zoom in to by using the mouse to click on a point on the drawing and then dragging the box outwards to select the area to be viewed The program will automatically scale the new view The original area can be restored by clicking on the restore zoom icon as shown here 4 3 13 2 Inserting Bitmaps If the site plan is available at a suitable scale in bitmap form then this can be placed behind the input data to check locations of loads etc The bitmap can be inserted in the following manner Select the bitmap button and open the required bitmap file This opens the Bitmap Scaling dialog Oasys Ltd 2015 Input Data Bitmap Scaling Bitmap area x min Cancel Load Bitmap Clear Bitmap Define the area required for the bitmap to cover in terms of maximum and minimum co ordinates and select Load Bitmap The bitmap is then placed behind the main graphic Oasys Ltd 2015 a Slope Oasys GEO Suite for Windows 4 3 13 3 SLOPEman sld Graphical Input Stratum Stratum 1 v Assigned material Made Ground ii ed ert ttt eeeedee tar Leet etter ret H H H 7 1 1 1 LV D D 1 D D A 3 i H i H 20 00 Scale x 1 363 y 1 363 Care should be taken not to copy large bitmaps which can dramatically increase the size of the file H the bitmap was used during data input it may be better to remove and store it separately from the
16. selection is made User defined sets of partial factors can be added or edited by selecting Partial Factors from the View menu See Reinforcement Calculations for details of the calculations used and the application of method and material partial factors 4 3 13 Graphical Input Selecting Data Graphical Input opens the graphical input view or it can be opened by clicking on the gateway The following data can be entered in graphical form Soil strata and groundwater level can be entered in both tabular and graphical form The methods are fully interchangeable and will update automatically kaft BR LN Strata Inserting a wedge of material Phreatic surface Piezometer levels and pressures Non circular slip surface Use the mouse to move the cursor around the graphical display The left and right mouse buttons allow data to be entered and edited Information on entering each type of data is given separately 4 3 13 1 Entering new graphical data Before entering data the program defaults to show a blank grid extending from 100m to 100m in the x direction and from Om to 100m in the y direction This range can be edited by selecting Graphics Scaling Set problem limits and then entering the maximum and minimum required for the x and y axes Oasys Ltd 2015 Input Data Problem limits Boundaries of problem x direction Min Dy Ne 100 Y direction Min 0 Max 100 Snap interval 0 1 m The
17. snap interval can also be edited if required This defines the smallest interval onto which the cursor will lock to mark a point Use the mouse to mowe the cursor around the graphical display The left and right mouse buttons allow data to be entered and edited To set an exact scale select Graphics Scaling Set Exact Scale and enter the required scale Specify Scaling Select scaling User specified Best fit Engineering C Independent XY scaling SetXscaleto 1 Ga Set Y scale to le The following buttons are available on the graphical input toolbar HE Axis Provides a reference grid behind the drawing Set Scale This allows the user to toggle between the default best fit scale and the closest available engineering scale e g 1 200 1 250 1 500 1 1000 1 1250 1 2500 Clicking on this button if an exact scale has been set will switch off the exact scale option Oasys Ltd 2015 52 Slope Oasys GEO Suite for Windows User specified Allows setting of a user defined scale which will be retained until switched off LA Save Metafile This save icon allows the file to be saved in the format of a Windows Metafile This retains the viewed scale The metafile can be imported into other programs such as a word processor spreadsheets and drawing packages bmp Bitmap This allows the user to insert a bitmap behind the main graphic on the Graphical Input screen X Zoom Facility The user can
18. strength 18 00 Drained linear strength Gateway a 21 00 Undrained 18 00 Drained linear strength E SLOPEman sld ro Calculation to show the main aspects of SLOPE including loads piezometric profiles and a grid of circle centres General Parameters Direction of slip DOWNHILL Minimum slip weight kN m 100 00002 Type of analysis STATIC Analysis Options Factor of safety on SHEAR STRENGTH Minimum number of slices 10 Method Bishop Variably inclined interslice forces Maximum number of iterations 100 Tableview Working with the Gateway The Gateway gives access to all the data that is available for setting up a Slope model Top level categories can be expanded by clicking on the symbol beside the name or by double clicking on the name Clicking on the symbol or double clicking on the name when expanded will close up the item A branch in the view is fully expanded when the items have no symbol beside them Double clicking on an item will open the appropriate table view or dialog for data input Oasys Ltd 2015 About Slope 3 1 3 2 Preferences The Preferences dialog is accessible by choosing Tools Preferences from the program s menu It allows user to modify settings such as numeric format for output show welcome screen option for new model wizard print parameters and company information These choices are stored in the computer s registry and are therefo
19. the reinforcement in the tabular output table Each set is drawn in a different colour on graphical input and output NB If the reinforcement is marked inactive in the Analysis Method dialog it is drawn in grey on the graphical input and omitted from the output because it has no effect on the results Geometry The uppermost level number of layers and horizontal spacing are entered The length of the top and bottom layers of reinforcement are entered The lengths of intermediate layers are interpolated between these two values The angle from horizontal is entered except for geotextiles which are always assumed to be horizontal Capacity Out of plane spacing tensile capacity and plate capacity if applicable are entered Plate capacity must be at least 50 of tensile capacity The tensile capacity should represent the allowable capacity if BS8081 is used or ultimate capacity if EC3 is used Bond details and prestress Bond length can be entered for ground anchors and rock bolts Type B Soil nails are assumed to be 100 bonded along their length Oasys Ltd 2015 ER Slope Oasys GEO Suite for Windows Bond strength can be specified or calculated from effective stress Prestress can be entered for ground anchors and can not exceed the tensile capacity Material partial factors Click the Select button to set material partial factors for each set of reinforcing elements This is optional all partial factors will be set to 1 0 if no
20. until a condition of limiting equilibrium is achieved The same factor of safety is applied to all strata Factor of Safety on Applied Loads In this case the program calculates a load factor as the factor of safety All the specified loads are then multiplied or divided by the load factor in order to bring the ground into a state of limiting equilibrium with the given shear strength parameters This facility only works when the loads are sufficiently large to have a significant effect on the stability of the slope Two types of load factor can be specified Disturbing In this case all loads are multiplied by the factor of safety until limiting equilibrium is achieved Restoring Here all loads are divided by the factor of safety until limiting equilibrium is achieved The first case can be used for bearing capacity or passive pressure problems and the latter for determination of required anchor forces or active pressures Distribute Surface Loads This option is only available for Janbu s method with variably inclined interslice forces and surface loads The option allows an initial calculation using elastic stress distributions to include for the spreading effects of surface loads Note This method has been used infrequently in design Results should therefore be treated with Oasys Ltd 2015 Input Data 31 caution 4 3 4 4 Partial Factor Analysis This option assists the user to perform calculations based on ULS p
21. 2015 Input Data Boundary number Ground level aD Se Fill Stratum 1 eH Ge Alluvium Stratum 2 dE SE Clay Stratum 3 Ee A soil boundary may not cross a vertical grid line twice thereby creating an overhang Vertical lines are also not permitted but must instead be modelled as near vertical __ minimum separation of 0 01 units A vertical wall or cut is therefore represented by a boundary of very steep gradient using a horizontal separation of at least 0 01 units This is so that the co ordinates can be read correctly from printed output which is given to 2 decimal places 4 3 13 3 2 Inserting a lens or wedge of material Where a lens of material C is embedded in another material B as shown below it is drawn with upper and lower boundaries that extend to the edge of the section et material A ee Thus material B is actually divided into two strata having the same properties and separated by the boundary of material C Oasys Ltd 2015 ER Slope Oasys GEO Suite for Windows Boundary number Material A Stratum 1 Material C dE Material B Stratum 4 Material D Stratum 5 The same applies for a wedge of soil that does not extend across the full width of the section Coincident boundary layers Fill Stratum 1 Gravel Stratum 2 We CH To enter a lens wedge or coincident layer of material 6 Clay Stratum 3 1 highlight the strata which
22. 43 59 F Factor of Safety 6 9 29 43 65 67 69 Applied Loads 30 66 Contouring 69 Shear Strength 30 Fellenius Method 5 10 28 File Multiple files 18 New Data file 18 G Gateway 2 General Parameters 28 Graphical Output 2 68 Graphics Toolbar 2 Grids 43 Groundwater 33 Hydrostatic pressure 34 Piezometric pressures 33 35 36 Ru value 38 Submerged Slopes 38 Groundwater Table s Graphical Input 59 Groundwater Hydrostatic pressure 33 H Horizontal Acceleration 28 Hydrostatic pressure 34 Interlock 9 Iteration Maximum number of 29 66 Procedure 8 Janbu s Methods 12 29 64 Distribution of Surface Loads 14 Oasys Ltd 2015 Index Janbu s Methods 12 29 64 Set Exact 50 71 Horizontal Interslice Forces 13 Slices Parallel Inclined Interslice Forces 13 Number of 29 Variably Inclined Interslice Forces 13 Positioning of 10 Job Number 26 Theory of 6 L Slip Movement 28 Slip Surface Circular 42 Loads 10 14 30 47 Definition 42 Factor of Safety 30 66 Non circular 61 M SLOPE Brief Technical Description 73 Description 1 Material Properties 10 32 Features 1 Minimum Slip Weight 28 Soil Suction 1 37 N Spencer s Method 12 Standard Toolbar 2 Strata Graphical Input 50 54 Non circular Slip Surfaces 12 61 Inserting lens or wedge 57 Notes 26 Multiple Layers 56 P Tabular Input 40 Submerged Slopes 10 38 Phreatic Surface 17 33 37 64 69 Suape Poad TTA So a7 Co ordinates of 59 Swedish
23. Circle Method 5 10 28 Graphical Input 33 50 59 T Hydrostatic pressure 33 34 Piezometric levels 33 35 36 Submerged Slopes 38 Table View 2 Piezometric pressure 35 36 Tabular Output 2 Piezometric pressures Tangent Surface 43 Adding data 17 33 35 39 Tension cracks 59 Interpolation 36 Titles Calculation title 26 H Window 27 Toolbar 2 References 72 Tunset Toolbar 2 results 72 Full 67 U Output 64 65 68 Summary 66 Undrained materials 10 32 Ru Value 38 Units 27 S User Interface 2 Scale Engineering 50 69 View menu 68 Oasys Ltd 2015 Slope Oasys GEO Suite for Windows Windows Metafile 50 69 Z Zoom Facility 50 69 Oasys Ltd 2015 Oasys Ltd 2015 Endnotes 2 after index
24. EEEEEEEEEEEEEEEEEEEEen 12 35 JANDU S Method EE 12 3 5 1 Janbu s Method Horizontal Interslice Forces ccssssssssssssssesecccceeeceeeseenensnsesnsncececeseseseenensesnsnseececeseseseeseees 13 3 5 2 Janbu s Method Parallel Inclined Interslice FOrcesS ssscccsscscesesseneneesssnsccececeseseseesensesesesncececesesesseseees 13 3 5 3 Janbu s Method Variably Inclined Interslice Forces ssssssssssesessssssssssesssesesessssssesesesaeaeseessneassesseneaeesenss 13 3 5 3 1 initial Distribution of Surface Loads Assisen veteeees te Sege S 14 3 6 Reinforcement Calculations cccceccssceeeseceeeenceeenceeeenseeeenseeenseneenseeenseeeensentensensensenees 14 4 Input Data 17 AT Assembling Data 3 gic recede ccs de cete eee hse cade ccteac cd cecasdde cet sectectsascdzcestadcccasssddecevsecccctsaeddecttsadeccess 17 4 2 Opening the Program cccceeeeeceeeee ener seen ee eeeeee ee RRE EE ERER nennu nnmnnn nnmnnn nnmnnn nnmnnn nnmnnn nennen 18 4 2 1 New Model WIZ aN WEE 19 4 2 1 1 New Model Wizard TitleS ANd Une iarnna n a a a a a E 19 4 2 1 1 1 Titles window BIMAPS EE 21 4 2 1 2 New Model Wizard Material a aa Edel e O Ea aaa EE 21 4 2 1 3 New Model Wizard Stratum Defnfton 22 4 2 1 4 New Model Wizard Ground Water Coordinates cccccccccccssccsssseesseccsseecssseecssecesseecssseccssecesseecsseeseseees 23 4 2 1 5 New Model Wizard Slip Surface Detton eee eects eee sneseewte tate sete seeetel 23
25. Method and satisfies conditions of horizontal vertical and moment equilibrium for the slip as a whole Assumptions 1 The program assumes that all the interslice forces are parallel but not necessarily horizontal i e at a constant inclination throughout the slope Where tan 0 X E X E n 1 n 1 6 angle of resultant of the interslice forces from the horizontal 2 This satisfies the condition of overall horizontal and vertical equilibrium 3 The method also satisfies overall moment equilibrium This method has been assessed by Spencer 1967 He has shown that in most cases the results differ only slightly from those obtained by the simplified method which assumes only horizontal interslice forces The differences between the two methods increase with slope angle For steep slopes Spencer s method is more accurate and is therefore recommended This method can have problems of interlock see Interlock If it is suspected that this may be a problem the method of variably inclined interslice forces should be used Bishop s Method Variably Inclined Interslice Forces This method is applicable to circular slip surfaces It is a further refinement of Bishop s method designed to over come the problems of interlock Assumption e In this method the program calculates the interslice forces to maintain horizontal and vertical equilibrium of each slice The inclinations of the interslice forces are then varied in each iterati
26. Occurs if the circle radius is too small to reach the specified ground surface Center embedded Circular Where the center of the circle is below the level of the top of the slip Top of circle Centre of circle No loads Circular Non Specify loads for factor of safety on loading Circular Loads too small Circular Non Increase load size until they become a significant factor in the Circular stability of the slope or change the factor of safety to shear strength Oasys Ltd 2015 Weight too small Circular Failed to converge Circular Analysis Error Circular 5 2 1 2 Full Results Analysis and Results Circular Non Decrease the minimum slip weight Circular Non Increase the maximum number of iterations Circular Non Occurs for general calculation errors Check input data Detailed results are provided for the slip circle slip surface with the lowest factor of safety The output provides details of the interslice and base forces in addition to the overall reporting of force and moment equilibrium FA SLOPEman std Output Notes Calculation to show the main aspects of SLOPE including loads piezometric profiles and a grid of circle cent General Parameters Direction of slip DOWNHILL Minimum slip weight kN m 100 Type of analysis STATIC Analysis Options Factor of safety on SHEAR STRENGTH Minimum number of slices 10 Method Maximum number of iterations 100 Reinforcement NOT ACTIVE Metho
27. RZUETIe CTT 65 5 2 1 1 SUMIMArY OT RES CN 66 E E Se GAME 67 53 Graphical Output ix Eege oh atic ee ease ca sede cians wh sce Sack ce red ac ce beeen NEEN 5 3 1 View Data and RO S U EC 5 3 1 1 Edit Graphics Settings oe 531 2 Set Scale xg hota eet niin inl sina rls wean iia te fared A Nav vi Ao ee ane ea 6 List of References 72 6 1 FREIGKE NCES oaiae anaana aena eaa aiaia aaa aaae eaae adea ii naaa aaa oae raa eataa na Enia 72 7 Manual Example 72 TM CC EE 72 Oasys Ltd 2015 m Slope Oasys GEO Suite for Windows 8 Brief Technical Description 73 B20 2SIOPe E 73 Index 74 Oasys Ltd 2015 About Slope 1 1 About Slope 1 1 General Program Description Slope has been designed primarily to analyse the stability of slopes with an option to include soil reinforcement It can also be used to analyse earth pressure and bearing capacity problems The program can check circular and non circular failures thereby allowing calculations to be carried out for both soil and rock slopes 1 2 Program Features The main features of Slope are summarised below e Slope provides the following methods of analysis Swedish circle Fellenius method Bishop s methods Janbu s methods The use of these methods allows analysis of both circular and non circular slip surfaces to be carried out The location of circular surfaces is defined using a rectangular grid of centres and then a number of different radii a common point through w
28. Slope Version 19 1 Oasys Oasys Ltd 13 Fitzroy Street London W1T 4BQ Central Square Forth Street Newcastle Upon Tyne NET 3PL Telephone 44 0 191 238 7559 Facsimile 44 0 191 238 7555 e mail oasyS arup com Website http www oasys software com Oasys Ltd 2015 Slope Oasys GEO Suite for Windows Oasys Ltd 2015 All rights reserved No parts of this work may be reproduced in any form or by any means graphic electronic or mechanical including photocopying recording taping or information storage and retrieval systems without the written permission of the publisher Products that are referred to in this document may be either trademarks and or registered trademarks of the respective owners The publisher and the author make no claim to these trademarks While every precaution has been taken in the preparation of this document the publisher and the author assume no responsibility for errors or omissions or for damages resulting from the use of information contained in this document or from the use of programs and source code that may accompany it In no event shall the publisher and the author be liable for anyloss of profit or any other commercial damage caused or alleged to have been caused directly or indirectly by this document This document has been created to provide a guide for the use of the software It does not provide engineering advice nor is ita substitute for the use of standard refere
29. able should be given a different name for easy recognition when associating the water table with the soil strata The x and y coordinates are entered in the table on each page For a new water table click on the Add water table tab Once finished adding or editing click on OK Note when reading files created before the stratum specific feature was added the original water table will be named Single This can be renamed as required 4 3 7 2 Groundwater with Piezometric Pore Water Pressure Distribution The Data Piezometer menu command opens this dialog or it can be opened by clicking on the gateway Sets of piezometers are added or edited by selecting Piezometers from the Data menu Each piezometer set should be given a name to easy recognition when associating the piezometer set with soil strata A phreatic surface with zero pressure must also be specified in the Groundwater Coordinates table This is required in order to provide an upper level for the interpolation of the pore water pressures Oasys Ltd 2015 ER Slope Oasys GEO Suite for Windows 4 3 7 2 1 FA SLOPEman sld Piezometer Coordinates SEE Driginal Add piezo set Name Original C The x and y coordinates are entered in the table on each page For a new piezometer set click on the Add Piezo Set tab Once finished adding or editing click on OK Note when reading files created before the stratum specific feature was added any original piezometer
30. acing m H 4 3 10 1 Circular Slip Surfaces A circular slip surface is defined by the x and y co ordinates of the centre of the circle and the specification of the circle radius The centre of the circle is specified in terms of a single point or grid The radius of the circle is specified in terms of e The co ordinates of acommon point through which all circles must pass e Defined radii of the circles For this case user can limit the radius value beyond which slips Oasys Ltd 2015 Input Data are not generated e A tangent surface defined as a stratum boundary In this case the circle stays just above the boundary A minimum slip weight can also be specified to prevent the program choosing very small slip circles that just intersect the surface of the soil 4 3 10 2 Definition of Circle Centres Single Point The user can specify a single centre of a circle in terms of x and y co ordinates Grids Y A rectangular grid of centres can be specified by giving the co ordinates x y of the bottom left hand corner of a grid and the inclination of the grid about this point in positive anticlockwise direction The extent of the grid is given by specifying the number of columns and the spacing of each grid line in the x and y directions There is an option to let the program extend the grid at the same grid spacing and inclination to find the minimum factor of safety If this option is used the program will ext
31. actored soil friction angle tan tan f c is factored soil cohesion a c f Yn is weight of soil above the reinforcement behind the slip surface soil unit weight is multiplied by the applicable partial factor where f msphi S factor on friction angle msphi Oasys Ltd 2015 16 Slope Oasys GEO Suite for Windows w is surcharge on the surface above reinforcement behind the slip surface with factors on dead and live load applied so w dead load x dead load factor live load x live load factor a is coefficient of interaction between reinforcement and soil relating to the of soil a is coefficient of interaction between reinforcement and soil relating to the c of soil K is the Rankine active earth pressure coefficient f is partial factor on pull out BS8006 1 3 f is partial factor for structure importance BS8006 1 1 1 If the bond strength is specified the value B used in the calculations is the user s specified value divided by f xf p n The only partial factor not used at the moment is f sliding along reinforcement which will be added in a later stage of development This would apply if the slip surface is within a certain distance from the reinforcement to reduce strength on slip surface Surcharges are excluded from the pullout calculation by default but can be included by setting the field Use in pullout calc in the Materials table to Yes See Partial Factors for definiti
32. applied equals the capacity of the reinforcement derived for the current slip surface If the reinforcement is used to contribute additional restoring moment the soil restoring moment is calculated as usual but with any partial factors taken into account then divided by the moment correction factor The reinforcement restoring moment is then added and the factor of safety calculated Calculation of design capacity of reinforcing elements where they cross the slip surface For end anchored elements rockbolts Type B T S For ground anchors without pre stress or soil nails capacity is the minimum of design pullout force tensile force and stripping force so T min T S BL S P BL S For ground anchors with prestress the applicable prestress cannot exceed this value The input prestress is reduced in proportion to the amount of fixed length outside the slip surface In the output the applicable prestress and any additional capacity are shown separately The applicable prestress per m run of slope is Tj min T T S x L L and the additional capacity is T Tal For geotextiles capacity is the minimum of design tensile force and pullout force so T min T 2L t where T is design tensile capacity per m run of slope Tt X LJ X fmia X fma1 X Lues X fy X LI where f is the partial factor for creep reduction Lux IS the partial factor for manufacture Oasys Ltd 2015 Methods of Analysis 15 fa12 S the part
33. artial factors Eurocode 7 Design Approach 1 Combination 1 Combination 2 etc In this method material factors are applied to angle of friction cohesion etc and loads are factored depending on whether they are favourable unfavourable and permanent variable The program calculates an over design factor instead of the traditional factor of safety and the terminology throughout the program is revised to show this For this type of analysis to be performed the user must select a ULS partial factors set in the Method Partial Factors dialog Note for EC7 DA1 1 Analyses The approach used for EC7 Design Approach 1 Combination 1 follows Simpson B 2011 Concise Eurocodes Geotechnical design BS EN 1997 1 Eurocode 7 Part 1 BSI Commenting on EC7 11 5 1 12 this states Paragraph 12 makes it clear that no attempt should be made to partition the sliding mass into favourable and unfavourable ground Even when the Design Approach or Combination in use requires different factors on favourable or unfavourable permanent actions the weight of the ground is to be considered as a single source in the terms of 2 4 2 9 This is at variance with the proposals of Driscoll R Scott P amp Powell J 2008 EC7 implications for UK practice CIRIA Report C641 4 3 5 Partial Factors Partial factors dependent on the method and on material parameters can be specified A default set of partial factors is provided in XML files w
34. ations of the method are similar to those of Bishop s Method The method is capable of giving misleading results due to the problem of interlock see Interlock The program prints a warning message if the calculated factor of safety is likely to be in error In such cases the method of Variably Inclined Interslice Forces should be used 3 5 3 Janbu s Method Variably Inclined Interslice Forces This method is applicable to both circular and non circular slip surfaces It is designed to overcome the problem of interlock When applied to circular slip surfaces the equation becomes identical to Bishop s method with Variably Inclined Interslice Forces and the calculated factor of safety is the same Oasys Ltd 2015 nu Slope Oasys GEO Suite for Windows 3 5 3 1 3 6 Initial Distribution of Surface Loads This method is applicable to slopes having surface loads It is an extension of Janbu s method with variably inclined interslice forces adding an initial calculation using elastic stress distribution to include for the spreading effects of the surface loads Note This method has been used infrequently in design Any results should therefore be treated with caution Reinforcement Calculations If reinforcement is specified and active the forces in the reinforcement are calculated and can be either specified as contributing additional restoring moment hence increasing the factor of safety or as surface loads where the surface load
35. bove ground level as in section CD below The pressure of water acting on the ground surface is treated as a surface load Pore pressures on the slip surface can be specified as either hydrostatic or piezometric see Groundwater The portion of the water surface outside the slope is usually horizontal and corresponds to static conditions Wave conditions could be modelled by defining a water surface as shown below Oasys Ltd 2015 Input Data The results however should be examined carefully to check that the actual pore pressure distributions on the ground and the slip surface are as required 4 3 8 Piezometers Piezometers are defined in named sets which can then be associated with one or more strata A piezometric distribution is specified using a series of pressure heads from individual piezometer locations within any one set The water pressure at any point in a stratum is computed by interpolating between either the nearest three piezometers of the associated set or the nearest two piezometers in the set and a point on the associated phreatic surface at the same x coordinate as the point at which the water pressure is required Note The piezometers should be distributed throughout the area of the slope and slip surface area to provide the best interpolation E SLOPEman sld Graphical Input Piezo Set Original Assigned material Seale x 1 443 y 1 443 Adding piezometers Piezometer data is ent
36. by importing DXF data files To impor a DXF file select the File menu then Import DXF File This brings up a dialog box allowing you to browse and select the DXF file that you wish to import Imported DXF files are shown in grey in the graphical input view To use these lines within the model the view needs to be set to the DXF Import mode this should occur automatically on opening the graphical input view after a DXF file has been imported To do this manually with the graphical input view open select the Graphics menu then Graphical input Import DXF With the graphical input display in Import DXF mode the data can now be imported into the model To do this left click on the uppermost DXF line or polyline that you wish to import In the following dialog box select whether you wish to import the layer as groundwater or a soil stratum and provide a name for the layer After clicking OK further details can be added to these layers if required using the other strata and groundwater input commands z Convert DXF Data to Model Data Import selected dxf data as Top of Stratum Groundwater Table Set imported layer name Oasys Ltd 2015 ER Slope Oasys GEO Suite for Windows It should be noted that only a single line or polyline can be imported at a time Consequently when creating a DXF file it should be ensure that either a single line or polyline is used to construct each layer Analysis and Resu
37. by selecting View Partial Factors Material Properties The Data Materials menu command opens this dialog or it can be opened by clicking on the gateway For each material type soil or rock the following data must be entered SLOPEman sld Materials 0 00 0 00 Drained linear strength 17 00 17 00 Drained linear strength 18 00 18 00 Drained linear strength 21 00 21 00 Undrained 18 00 18 00 Drained linear strength Description For the material General e A description of the stratum e The bulk unit weight kim of the material above and below the ground water table e Colour of the material on the graphical output Shear Strength Parameters e The condition of the material i e undrained drained with linear strength or drained with strength calculated using a power or hyperbolic function Choose the required option from the drop down list For drained linear strength materials enter the angle of friction d deg and a value for drained cohesion c For drained power curve strength materials enter the angle of friction at which a linear relationship takes over plus the two constants a and b Slope calculates the material strength using a relationship of t ao_b Oasys Ltd 2015 Input Data 33 Then r Jl abo P which is equal to tan at o The associated c is given by c abo 1 b The linear relationship t c o on takes over at some predetermined say d When o exceeds the s
38. cting Tabular Output from the Gateway has the same effect Before displaying the tabular output the program requests confirmation of which data results to show 5 2 Results Output The results are provided in tabular form The lists of tabulated output can be highlighted and then copied to the clipboard and pasted into most Windows type applications e g Word or Excel The output can also be directly exported to various text or HTML formats by selecting Export from the File menu Slice Strength Parameters Average Slice Forces on base kN m No Pore Weight Pressure c Tan phi kKN m kN m Normal Shear Shear kN m2 capacity mobilised 1 0 0 0 5543 0 0 2 275 2 451 1 359 1 450 2 0 0 0 5543 0 0 6 380 6 307 3 496 3 730 3 0 0 0 5543 OO 94 652 92277 5 142 5 487 4 0 0 0 5543 0 0 12 10 11 39 6 314 6 737 5 0 0 0 5543 D SSG Leen 1035 7 506 6 0 0 0 5543 DD 14563 13 24 Taso 7 829 7 0 0 0 5543 0 0 14 76 13 10 7 259 7 745 8 0 0 0 5543 Daf k ko 12 35 6 844 7 303 9 0 0 0355 43 0 0 12 98 11 08 6 140 65 552 10 0 0 0 5543 Of EELER 9 330 5200 5 548 11 0 0 0 5543 0 0 8 850 7 352 4 075 4 348 12 0 0 0 5543 0 0 4 329 9 340 BECH 5 524 13 2 000 0 3640 0 0 0 4393 2 950 1 846 1 969 The results for Slope are reported in two formats A summary of the results for all the slip circles analysed and a full report of the results for the worst case slip circle with the lowest factor of safety 5 2 1 Slip Surfaces This output summarises the results fo
39. d Partial Factors Current selection SLS Factor on DEAD LOAD 1 0 Factor on LIVE LOAD 1 0 Factor on SOIL UNIT WEIGHT 1 0 Factor on DRAINED SOIL COHESION 1 0 Factor on UNDRAINED SOIL COHESION 1 0 Factor on SOIL FRICTION ANGLE 1 0 Moment correction factor 1 00 Factor on reinforcement pullout 1 00 Economic ramification of failure 1 00 Sliding along reinforcement 1 00 lt Full output comprises the following Method of Analysis Location of slip surface Overall Results Includes net vertical and horizontal forces to help provide some idea of the possible error in the calculated factor of safety Oasys Ltd 2015 Bishop Variably inclined interslice forces See General Number of iterations Horizontal Acceleration g x and y co ordinates of the center of rotation about which moment is taken Radius for circular slips Net vertical force Net horizontal force Slip weight ER Slope Oasys GEO Suite for Windows 5 3 Slip Surface Location x and y co ordinates m m OD of the base of the LEFT side of each slice are used to define the location of the slip surface Slices Slices are numbered from left to right General Slice Information Graphical Output Disturbing moment Restoring moment Factor of Safety or Over Design Factor Pore water pressure u Interslice Forces Vertical Shear T Horizontal Normal E Horizontal Water Pressure E u Strength Parameters Coh
40. e X Vertical Interslice Force W Total weight of soil ybh N Total normal force acting along slice base R Distance from slice base to moment centre S Shear force acting along slice base h Mean height of slice b Width of slice L Slice base length b cosa u Pore pressure at slice base Oasys Ltd 2015 Methods of Analysis a Slice base angle to horizontal x Horizontal distance of slice from moment centre y Vertical distance of slice surface from moment centre y Unit weight of soil c Cohesion at base Angle of friction at base 3 2 1 General Equations The general expression to calculate the average overall factor of safety for a circular slip circle is B E ZSR _ Restoring moment ft e eo a Se te Disturbing moment Where S cL N uL tan and N W P X X cos a E E P sin a Note As the factor of safety F is directly related to c and tan 4 it is a factor of safety on material shear strength For models which include soil reinforcement the additional restoring moment contributed by the reinforcement is added to the soil strength restoring moment For details of the method of calculation see Reinforcement Calculations In addition other expressions for equilibrium are as follows For vertical equilibrium N cos a W P X X S sin a F For horizontal equilibrium N sin a E E P S cos a F n 1 For non circular slip circles the equations
41. e strata Strata can not cross each other To insert wedges or lenses of material the same rules must be applied to the tabular input as for the graphical For further information see Inserting a lens or wedge of material Strata can also be imported from DXF files see the section on Importing DXF Data Oasys Ltd 2015 ER Slope Oasys GEO Suite for Windows 4 3 10 Slip Surface Definition Slip surfaces can be defined in terms of e Circular or e Non circular profiles The type is selected in the General Parameters dialog The remainder of the definition for circular slips is given via the following dialog box The Data Slip Surfaces menu command opens this dialog or it can be opened by clicking on the gateway Non circular slips are defined using the graphical input screen or table as shown in Non Circular Slip Surfaces FA SLOPEman Slip Definition Circle centre specification Circle radius specification Single Grid Common point Tangent surface Coordinates of bottom left if a grid specified O Defined radi shd 15 y m mn Angle of rotation deg 0 about bottom left of the grid Initial radius m Increment m Coordinates x m a 1 y m Tangent to stratum Limiting radius m Centres on grid Features of grid Definition of centres about local axis SE Eege Extend grid to find minimum factor of safety x direction y direction number 10 number 10 spacing m 1 sp
42. e up to 60 Other methods of analysis are therefore normally preferred 3 4 Bishop s Methods Bishop s methods Bishop AW 1955 are applicable to circular slip surfaces One of the Bishop methods must be used if reinforcement is specified Three methods of solution are available These are Horizontal Interslice Forces Parallel Interslice Forces Variably Inclined Interslice Forces 3 4 1 Bishop s Simplified Method Horizontal Interslice Forces This method is applicable to all circular slip surfaces Assumptions 1 The interslice shear forces are assumed to sum to zero This satisfies vertical equilibrium but not horizontal equilibrium where X R Al 0 This leads to errors in the calculated factors of safety but these are usually small and on the safe side Spencer 1967 2 The method satisfies overall moment equilibrium The limitations of the method have been investigated by Whitman and Bailey 1967 They concluded that the method can occasionally give misleading answers particularly in the case of Oasys Ltd 2015 12 Slope Oasys GEO Suite for Windows 3 4 2 3 4 3 3 5 interlock see Interlock If it is Suspected that this may be a problem then the user should select the method of Variably Inclined Interslice Forces Bishop s Method Parallel Inclined Interslice Forces This method also known as Spencer s Method is applicable to circular slip surfaces It is a refinement of Bishop s Simplified
43. end the grid in any direction if it is found that the centre of the slip surface with the minimum factor of safety is on the edge of the grid This process is repeated until the minimum centre is no longer on the edge of the grid 4 3 10 3 Definition of the Circle Radii Common Point This allows entry of co ordinates for a common point Xc Yc through which all circles must pass Oasys Ltd 2015 a Slope Oasys GEO Suite for Windows Actual specified location of common point Ifa common point is required at the toe of the slope then the actual point location should be set slightly above the toe This is in order to avoid problems from rounding errors Defined Radii Circles of different radii may be analysed by specifying an initial radius r and an increment of radius Ar For each centre the program then analyses circles of radii rt Apr 2Ar etc left limit of section right limit of section Circles of small radius are ignored by the program if they do not intersect ground level e g circles A and B The initial radius r may therefore be set to a small value Each section of strata has defined limits in the x direction The largest circle radius which can be analysed is determined by the limits of this section Circles C D and E are therefore analysed but not circle F If the value of Ar is given as zero the program analyses a single circle of radius r at each grid location Oasy
44. ered graphically by selecting the piezometer button t on the graphics toolbar Oasys Ltd 2015 ER Slope Oasys GEO Suite for Windows 4 3 9 A piezometric groundwater profile can be entered by placing the cursor at the appropriate level on the graphical view and clicking the right mouse button This opens the piezometer data box Piezometer Data x coordinate m 5 y coordinate m 5 Level of water m do This allows the level of the piezometer to be confirmed or edited and the corresponding level of water at the piezometer h to be entered The pressure u is given as U h hw where hp The level of the piezometer tip h The piezometric water level y co ordinate Y Unit weight of water as entered in Groundwater Piezometers can be deleted by placing the cursor over the location and clicking the left button whilst holding down the Shift key Strata The Data Strata menu command opens this dialog or it can be opened by clicking on the gateway in which strata coordinates can be entered in tabular form and the water data associated with the stratum entered or selected from dropdown lists Strata coordinates assigned material and name can also be entered in the graphical input view Oasys Ltd 2015 Input Data FA sLoPEman Stratum Definition Stratum 1 Stratum 2 Stratum 3 Stratum 4 Stratum P Add stratum Name Stratum 1 Stratum Coordinates k a a Material Made Ground w d Co
45. esion c tan dl degrees Pore Pressure Slice weight Forces on the base Normal N Shear S Surface Loads Vertical and Horizontal Water pressure on ground surface Vertical Horizontal Graphical output of the data and results is accessed via the View menu or the Gateway The following provides details of the available graphics options File Edit Data Analysis Tools Window Help Toolbars gt v Status Bar vw Gateway Partial Factors Graphical Output Tabular Output For information on the use of the Toolbar and Status bar functions please see the Index list Oasys Ltd 2015 Analysis and Results e 5 3 1 View Data and Results Select View Graphical Output to obtain a plot of the input data and results or open it by clicking on the gateway If more than one slip surface has been analysed the program defaults to show all slip circles or by default a maximum of 5000 slip circles coloured in accordance with their factor of safety Slope 19 0 SLOPEman sld File Edit View Data Analysis Tools Graphics Window Help 28 D EE RH m a A a 5 Input Units General Parameters Analysis options Method Partial Factors EE r r r r Water Profiles Titles 8 466 i i d Materials Hl j WZ Z Single 5 Ground Water ee tt Single HI d Piezometers Original 4 amp Strata Stratum 1 5 Stratum 2 5 Stratum 3 4 Stratum 4 6 Stratum 5 6 Slip surfaces Surface loads 1
46. gn capacities T and Tj will be resolved into horizontal and vertical load components and applied at the point where the reinforcing element intersects the ground surface The load applied to each slice will be shown in the Point Loads columns of the detailed results output table 4 Input Data 4 1 Assembling Data It is recommended that the following data are gathered for input to Slope ground surface location of each of the soil or rock strata phreatic surface location of any piezometers location and magnitude of any loads location of the grid of centres for circular failure or the plane of failure for a non circular slip Oasys Ltd 2015 Slope Oasys GEO Suite for Windows surface Note The co ordinates for all changes in slope for both the strata and phreatic surface should also be defined 4 2 Opening the Program The following provides details of all the information required to run Slope On first opening Slope the Welcome to Slope dialog is displayed To start a new project file select Create a new file This will open the New Model Wizard unless the New Model Wizard has been disabled in which case an empty model will be created Welcome to Slope is Oasys Slope 19 0 Home Page Create a new file Open an existing file Select recent file SLOPE_man_Inclined_Grid sid Slope_Man_NonCirc sld SLOPEman sld SLOPEman sld Show this welcome screen on startup This will open a new Titles wind
47. gth parameters for the condition will be activated Refer to Materials for more details Shear strength parameters e deg angle of friction e c drained cohesion e Go undrained shear strength at a specified elevation y e k the rate of increase of shear strength with depth e c p A ratio for normally consolidated soils where p is the effective vertical stress which is calculated by the program at the point on the slip surface for each slice e aandb constants described in Material Properties New Model Wizard Stratum Definition This page allows the user to enter a single stratum New Model Wizard Stratum Definition Stratum Cocedinstes Name Material Pore piessure distribution Hychostatic None Uni weight of groundwater Nz e Name Name ofthe stratum By default the stratum name will be Stratum 1 e Material The user cannot edit this field By default it is the material defined in the materials page e Pore pressure distribution The user has only two choices for selection here either hydrostatic or none If the user selects Hydrostatic then the next button in this page will route the user to the Ground Water page where he can define the ground water table If the user selects None then the Next button will route the user to the Slip Surface Definition page directly Oasys Ltd 2015 Input Data 23 e Unit weight of groundwater The unit weight of groundwater if pore pressure di
48. hich all circles must pass or a tangential surface which the circle almost touches Non circular slip surfaces are defined individually as a series of x and y coordinates The ground section is built up by specifying each layer of material from the surface downwards as a series of x and y coordinates The strength of the materials is represented by specifying cohesion and an angle of shearing resistance Linear variations of cohesion with depth can also be entered The ground water profile and pore water pressure distribution can be set individually for each soil stratum using either A phreatic surface with hydrostatic pore pressure distribution A phreatic surface with a user defined piezometric pore pressure distribution An overall value of the pore pressure coefficient Ru A maximum soil suction can also be specified for each stratum e Any combination of reinforcement consisting of horizontal geotextiles or horizontal or inclined soil nails rock bolts or ground anchors can be specified The restoring moment contributed by the reinforcement is calculated according to BS8006 1995 e Slopes which are submerged or partially submerged can be analysed External forces can be applied to the ground surface to represent building loads or strut forces in excavations e Horizontal acceleration of the slip mass can be included to represent earthquake loading e The calculated factor of safety can be applied to Soil strength or the magn
49. ial factor for extrapolation of test data fro IS the partial factor for damage fa22 S the partial factor for environment f is the partial factor for economic ramification of failure f is the partial factor for material strength T is input prestress per anchor S is out of plane spacing B is bond strength force per unit length of anchor nail P is design surface plate capacity L is bonded length within the slip circle Lo is bonded length or length outside the slip circle L is total bonded length The calculation of pullout and stripping forces are mentioned above To calculate them the shear bond strength of the appropriate soil strength model has to be applied to the material the reinforcement is in linear hyperbolic etc B is bond strength force per unit length of anchor nail which can be calculated or specified by the user If calculated the value is based on equation 12 from BS8081 or section 4 3 2 of BS8006 2 For BS8081 the equation to calculate bond strength is Die jang GJ xf where o Tur W vertical h is vertical distance between reinforcement and slope surface For BS8006 2 the equation to calculate bond strength is mD a tand GJ where o 0 1 K 2 and K 1 K 2 Shear strength of soil t o a tan GI x f for drained linear strength model It should be noted that a reduced pullout factor is adopted in this analysis as the factored strength and friction angle are used 8 is f
50. ing on the gateway Surface loads can be added by defining the lateral extent of the loaded area in terms of the left and right limits SLOPEman sld Surface Loads me SS Sec KN Zm hor m DECHE load a a load4 Use in CH Variable load UnFavourable a calc Horizontal 00 Permanent Limits of ere Area Vertical 0 00 Variable Load Left m Loads can be placed horizontally or vertically Oasys Ltd 2015 ER Slope Oasys GEO Suite for Windows 4 3 12 Lateral extent of loaded areas x m Right Left Right vertical load r 2 Left ec y inclined load AAR EES Vertical loads are expressed as the vertical force per unit horizontal width of the loaded area For level ground this is equal to the normal stress on the ground surface Vertical loads are positive when they act downwards Horizontal loads are expressed as the horizontal force also per unit horizontal width of the loaded area For level ground this is equal to the shear stress on the ground surface but for steeply inclined surfaces the pressure specified is much greater than the actual pressure acting on the ground Horizontal loads are positive when they act in the direction of increasing x Inclined loads can also be defined by using a combination of the horizontal and vertical components Concentrated loads in the form of anchors or struts can be modelled by specifying surface loads of high intensity over short lengths of
51. ip would be extended either along the slope of the last segments or vertically depending upon the choice by the user made in the General parameters The following figure depicts the checks and amendments done by the auto correct function N idered fi alysi Terminated on The slip surface either projected or extended vertically PERO SE intersection with ground as per the users choice a RSR ew Fal 20 00 10 00 D 10 00 Following are the cases where the auto adjustment of slip would fail 1 Only 1 point exist for the curve 2 Curve completely outside 3 Inappropriate intersection with ground 4 On extension or vertical projection as per the choice by the user the slip does not intersect the ground surface Note You can follow the exact co ordinates of the cursor by looking at the given x and y co ordinates at the top left of the screen x 1 418 y 0 5000 Editing the surface Oasys Ltd 2015 Input Data e To edit the location of a point 1 Place the cursor over the point and click the right button This brings up an editing box as shown Coordinates x coordinate m y coordinate m 2 Amend the co ordinates as required and then click OK Note Points can be deleted by placing the cursor over the required point and clicking the left mouse button at the same time as holding down the Shift key on the keyboard 4 3 13 6 Importing DXF Data Groundwater and strata layers can also be added to a model
52. is for vertical equilibrium Constant inclined interslice forces In this method Slope varies the ratio which is constant between the vertical and horizontal interslice forces until the resultant of each is reduced to zero For this method each slice is not in equilibrium only the slope as a whole In the calculation equilibrium is effectively maintained for each slice in the direction normal to the interslice forces Variably inclined interslice forces The variably inclined method is superior as it keeps every slice in horizontal and vertical equilibrium at all times However it can exceed the soil strength along the slice interface as it does not check the vertical interslice forces against the shear strength of the material The results should therefore be checked for this criterion The interslice force is adjusted separately for both the vertical and horizontal direction by adding the fraction of the residual values from the previous iteration The fraction is determined by the horizontal length of the slip surface represented by that slice The interslice force direction can vary by this method but each slice is in equilibrium at all times as is the slope as a whole Oasys Ltd 2015 Methods of Analysis 9 3 2 1 2 Interlock Bishop 1955 pointed out that there are a variety of force distributions which will satisfy the conditions of equilibrium In many cases the assumption of horizontal or parallel inclined interslice fo
53. is required to form the partial upper boundary of the new layer this is done by selecting the stratum number from the drop down box Assigned material Made Ground H y Stratum lt New Stratum gt 2 select the wedge button from the graphical toolbar This will place a new layer of material immediately on top of the highlighted layer 3 Delete the points on the line which are to be removed Shift Left mouse button 4 Place new points at the correct locations 5 Select the correct material type for the new layer or wedge of material Assigned material s 2 EIS Ee Made Ground Gand Clay Sand Lens Oasys Ltd 2015 Input Data s For inserted layers the stratum numbers will automatically re order to incorporate the new layer 4 3 13 4 Co ordinates of the water table Graphical input The co ordinates of any number of phreatic surfaces are entered in a similar manner as for strata To enter a new surface 1 Select the icon for addition of a phreatic surface 2 Select lt Add new gt from the Stratum dropdown box 3 Place the cursor at the correct location of a point which you wish to define as part of the surface and left click with mouse button The point will then Snap to the closest location defined by the given snap interval Note You can follow the exact co ordinates of the cursor by looking at the given x and y co ordinates at the top left of the screen x 1 418 y 0 5000
54. ith the program This default set includes factors recommended by e BS EN 1997 1 2011 Eurocode 7 Design Approach 1 combinations 1 and 2 e BS8006 1 2010 Sections 7 and 8 ULS e BS8006 2 2011 Sets 1 and 2 If no partial factor set is selected the program assumes all factors equal to 1 0 If the analysis options are set to Partial Factor Analysis and no partial factor set is selected a pre analysis error will be given Method partial factors can be applied to favourable or unfavourable loads soil unit weight drained or undrained cohesion soil friction angle restoring moment reinforcement pullout economic ramifications of failure sliding along reinforcement not currently used Oasys Ltd 2015 32 Slope Oasys GEO Suite for Windows 4 3 6 Separately each reinforcing element or group can be assigned a set of material partial factors by selecting the required set in each page of the Reinforcement dialog These factors are applied in the reinforcement calculations to represent friction and adhesion interaction creep reduction factor on manufacture extrapolation of test data factors on damage and environment factor on the element strength User specified factors can be added and will then be stored in the XML files if a data file containing user defined values is sent to another user the values will be extracted from the data and saved to the second user s XML file All available partial factors can be viewed
55. itude of the applied loads either a causing failure to represent bearing capacity problems or b preventing failure for anchor forces Oasys Ltd 2015 2 Slope Oasys GEO Suite for Windows 1 3 1 3 1 e Over Design Factor can be calculated for an ultimate limit state factor set using Partial Factor Analysis Components of the User Interface The principal components of Slopes s user interface are the Gateway Table Views Graphical Output Tabular Output toolbars menus and input dialogs These are illustrated below iTA Standard Toolbar Slope Toolbar Graphics Toolbar yy Sas are SE DCS JES SLOPEman std Graphical Input B Input Units Stratum Stratum 1 E igne Graphical Output General Parameters lr Nore ran ore slip surtce shown Analysis options edel Input 7 7 i H 7 H Water Prot Method Partial Factors 7 H i i i 7 b i EZZ Titles SE HE tae ak VILLA Materials 4 z N t Ground Water Sek HE ae EE S o Ss Factors of Single 4 7 Piezometers Original 4 H H t H e Strata mp ET Stratum 1 5 eee il SE SE Lif Uy eae ee ae E SE ee i Stratum 4 6 Stratum 5 6 Slip surfaces Surface loads 1 a AAAA sld Materials Sele Reinforcement Graphical Input Bee Ee a ee S Output ror ae KN m Shear strength p arameters Tabular Output Above Below pl Cohesion yO m cu p Graphical 0 GWL GWL i0 OR c0 s Kei OR b ratio SES Ques 0 00 Drained linear strength 17 00 Drained linear
56. lation This can be reproduced at the start of the data results output by selection of notes using File Print Selection Oasys Ltd 2015 Input Data 4 3 1 1 Titles Window Bitmaps The box to the right of the Titles window can be used to display a picture beside the file titles To add a picture place an image on to the clipboard This must be in a RGB Red Green Blue Bitmap format Select the Paste button to place the image in the box The image is purely for use as a prompt on the screen and can not be copied into the output data Care should be taken not to copy large bitmaps These can dramatically increase the size of the file To remove a bitmap select Remove 4 3 2 Units The Units dialog is accessible via the Gateway or by choosing Data Units from the program menu It allows the user to specify the units for entering the data and reporting the results of the calculations These choices are stored in and therefore associated with the data file Quantity Conversion factor Displacement 1000 per m Force 0 001 per N Length level R 1 perm Stress 0 001 per Pa Reset Units Default options are the Syst me Internationale SI units KN and m The drop down menus provide alternative units with their respective conversion factors to metric Standard sets of units may be set by selecting any of the buttons SI kN m kip ft kip in Once the correct units have been selected then click OK to conti
57. lipboard This must be in a RGB Red Green Blue Bitmap format One option is to press Print Screen while the_Graphics View is active to place a bitmap of the results on the clipboard Select the Paste button to place the image in the box The image is purely for use as a prompt on the screen and cannot be copied into the output data It is also useful when viewing the file in the Oasys Columbus document management system Note Care should be taken not to use large bitmaps These can dramatically increase the size of the file Select the Copy button to copy the image to the clipboard for pasting elsewhere To remove a bitmap select the Remove button 4 2 1 2 New Model Wizard Material This page allows the user to define a single material New Model Wizard Material Description Shear Strength Parameters Name 20 Condition Diained linear zeng w o 2 N er a b c p The following data is entered in the material page Name The name of the material The default name will be Material 1 Unit weight The bulk unit weight of the material above and below the ground water table Oasys Ltd 2015 22 Slope Oasys GEO Suite for Windows 4 2 1 3 Condition The condition of the material i e undrained drained with linear strength or drained with strength calculated using a power or hyperbolic function Choose the required option from the drop down list Depending on the selection the valid shear stren
58. lts Analysis and Data Checking Results can be obtained by clicking the Analyse button on the Slope Tool bar or via the Analysis menu File Edit View Data Graphics Window Help Delete Results Prior to analysis the program carries out a data check Data check Checking data No errors found select OK to proceed with analysis The data checks carried out are as follows The presence of a non circular slip surface if defined in the General Parameters Checks the authenticity of non circular slip surfaces Check if the Janbu method is defined in Analysis Methods for a non circular slip surface The presence of piezometers for a defined piezometric groundwater case The presence of upper and lower phreatic surfaces if a number of phreatic surfaces are defined in the Groundwater table For problems with horizontal loads or a submerged slope the analysis method is Bishop or Janbu 6 Soil bulk unit weights are not less than the unit weight of water 7 Checks whether a ULS partial factors set is selected if the analysis option is Partial Factor Analysis 8 Checks whether an SLS partial factors set is selected if the analysis option is Global factor of safety on shear strength or on loads RODD on If no errors are found then the calculation can proceed Select OK Oasys Ltd 2015 Analysis and Results e Note The option to Examine results becomes available once the calculations have been completed Sele
59. nces The user is deemed to be conversant with standard engineering terms and codes of practice Itis the users responsibility to validate the program for the proposed design use and to select suitable input data Printed March 2015 Slope Oasys GEO Suite for Windows Table of Contents 1 About Slope 1 1 1 General Program Description c ceceeeeeeeee seen ee ee esse ee RRE RRE EEERER EE ERER nnmnnn nnmnnn nnmnnn nnmnnn 1 1 2 Program Features iaczco cece cde ccececcectieecccedies Sect eeccc ee ctee a NNA ANEKA ANEAN s 1 1 3 Components of the User Interface cccceececeeeeeeeeeeeeeeeeeeeeeeeeeeeee se ERER EE ERER EE RRER nnmnnn nnmnnn 2 1 3 1 Working With KREE UE 2 VE ET ET 3 2 Step by Step Guide 4 3 Methods of Analysis 5 Sed GONELAD EE 5 3 2 Theory EE 6 3 2 1 General Equations ssscscsssessssssssseesssseseeeeiees 3 2 1 1 Method of Iteration vi 3 2 1 2 Interlock gt 22 28 nates A Se Ne eet Dd Sel aioe ge ant dots 3 2 1 3 _ ten Unie Bee 3 3 Swedish Circle Method FelleniusS kee ENNEN RRE ENNEN ENEE REENEN REENEN 10 3 4 Bishop s Methods i gees eceesggdEe ees ee ee 11 3 4 1 Bishop s Simplified Method Horizontal Interslice Forces seen 11 3 4 2 Bishop s Method Parallel Inclined Interslice FOrC S scssrsseseeeeseteeeneeeeneneeseenenenaeteneneeaenenenenaeenens 12 3 4 3 Bishop s Method Variably Inclined Interslice Forces eeeeeeeEeEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
60. nue SI units have been used as the default standard throughout this document Oasys Ltd 2015 Slope Oasys GEO Suite for Windows 4 3 3 General Parameters The Data General Parameters menu command opens this dialog or it can be opened by clicking on the gateway The following general information is required to describe the type of slip circle to be analysed FA SLOPEman sld General Parameters Slip surface type Direction of slip O Circular 7 Non circular Downhill O Increasings Decreasing x Projec Slip Along Slip E Minimum weight kN Type of analysis Horizontal acceleration Col Static Pseudo static Slip Surface Type see Slip Surface Definition Circular or Non circular Selection of the type of slip surface i e Circular or Non Circular slip surfaces In case of Non Circular slip surfaces the program would complete the slip to meet the ground surface by projecting the slip segments to meet the ground surface or vertically up depending upon choice by the user Minimum Slip Weight This is minimum weight of slipped soil and can be used to prevent the program analysing very small circles which just intersect the soil surface Type of analysis Selection of static or Pseudo static corresponds respectively to a file without or with horizontal acceleration Horizontal Acceleration g This allows the user to model earthquake loading The acceleration is applied to the soil mass within
61. ny required scale for the graphics This is done using the following data entry screen Oasys Ltd 2015 Slope Oasys GEO Suite for Windows Specify Scaling Select scaling User specified Best fit Engineering C Independent XY scaling SetXscaleto 1 323 SetY scaleto 1 List of References References Bishop A W 1955 The use of the Slip Circle in the Stability Analysis of Earth Slopes G otechnique Vol 5 No 1 pp 7 17 Janbu N 1957 Earth Pressures and Bearing Capacity Calculations by Generalized Procedure of Slices Proc 4th International Conference Soil Mech Fdn Engng Vol 2 pp 207 212 Nash D 1987 A comparative review of limit equilibrium methods of stability analysis in slope stability Anderson and Richards eds John Wiley amp Sons Spencer E 1967 A Method of Analysis of Embankments ensuring Parallel Interslice Forces G otechnique Vol 77 pp 11 26 Whitman R V and Bailey W A 1967 Use of Computers for Slope Stability Analysis International Soil Mech Fdns Div Am Soc Civ Engrs Vol 93 SM4 pp 475 498 Manual Example General The data input and results for the Slope manual example are available in the Samples sub folder of the program installation folder The example has been created to show the data input for all aspects of the program and does not seek to provide any indication of engineering advice Screen captures from this example have also been used throughout
62. on of each required phreatic surface is defined in either the Groundwater window or the Graphical Input window For information on data entry see Co ordinates of the Water Table Graphical Input and Importing DXF Data Oasys Ltd 2015 a Slope Oasys GEO Suite for Windows 4 3 7 1 Groundwater with Hydrostatic Pressure Distribution The pore water pressure is calculated at the slip surface using the following assumptions The pore water pressure at the location of the slip surface A is calculated from the level of groundwater vertically above at B Jos Be slip surface flow line equipotentia This assumes that the distribution of pore water pressure is hydrostatic and that the lines of equipotential are vertical As can be seen by the flow net above this is not strictly correct The correct pore water pressure should be calculated from column AD the vertical distance between A and C described by the actual line of equipotential For most practical problems the error created is small and leads to conservative results The Data Groundwater menu command opens this dialog or it can be opened by clicking on the gateway To enter the coordinates of each required phreatic surface choose Groundwater from the Data menu This opens the Groundwater Coordinates table Oasys Ltd 2015 Input Data 35 FA SLOPEman sld Groundwater Coordinates SEE Singe Add GW profile Name Single Each groundwater t
63. on of the method and material partial factors Calculation of additional restoring moment due to reinforcing elements The additional restoring moment due to the reinforcement is defined as Mar Mat May where Mar is the sum of moments due to tension in the nails anchors and May is the sum of moments due to shear in soil nails Calculation of shear developed in soil nails is not included so the equation reduces to z TajR F aj j Man Mer gt sin 9 wj x 5 j 1 o Optionl X 0 sinw tan Option2 X VE sin6 cos tanga Option3 X cos 6 a wj tanpa The component X represents the nail tension increasing the normal force on the slip surface these are adapted from Figure 18 of BS8006 2 2011 For anchors with prestress BS 8081 applies and an additional restoring moment due to prestress is Oasys Ltd 2015 Methods of Analysis m MRF K bp tan Ai cosl ell j 1 where Ty is the applicable prestress as defined above Circle Centre Critical Slip Surface T design tensile capacity of the reinforcing element S the horizontal spacing of reinforcement V design available shear resistance Ry radius of the slip circle d angle of the radius from the horizontal o angle of the reinforcing element from the horizontal Application of reinforcement forces as surface loads If the Apply as Surface Loads box is ticked currently available for soil nails and ground anchors then the desi
64. on of the phreatic surface s where these lie within the strata to which they are assigned View Surface loads RE Surface Shows the location of the slip surface For circular surfaces the centre of the currently plotted circle is also highlighted Slices Shows the location of the slices analysed Contours Provides a contour plot of the factor of safety for the grid of slip circle centres Plot all circles The user can toggle between all the circles and only worst case circle via this button Slice diagram Em This button is enabled when the slices are drawn on the circle Click this button then on the required slice A separate view showing the forces on the slice and a force polygon will be opened or updated if a different slice was previously shown Right clicking on any force vector in the force polygon will open a dialog box showing the component of force and it s magnitude a al gl Add Edit Label This allows entering of text labels on the view To add a label click the Add Label button enter the details then click at the required label position To edit or delete an existing label click the Edit Label button right click near the required label and edit the details as required Note To change the currently plotted circle when a grid of centres has been analysed move the cursor into the grid it will change to a cross hair and right click on the required centre The circle with the lowest fac
65. on until overall horizontal vertical and moment equilibrium is also achieved Janbu s Methods Janbu s methods are applicable to non circular slip surfaces The method reduces to the Bishop solution for circular slip surfaces Three methods of solution are available Oasys Ltd 2015 Methods of Analysis 13 Horizontal Interslice Forces Parallel Inclined Interslice Forces Variably Inclined Interslice Forces 3 5 1 Janbu s Method Horizontal Interslice Forces This method is taken from Janbu 1957 and is applicable to non circular slip surfaces Assumptions e The assumed force distribution satisfies overall vertical and horizontal equilibrium but not moment equilibrium The above leads to errors in the calculated factors of safety These are on the safe side but can be up to 15 The more refined Janbu methods using Inclined Interslice Forces are therefore recommended 3 5 2 Janbu s Method Parallel Inclined Interslice Forces This method is applicable to both circular and non circular slip surfaces Assumptions e Horizontal and vertical equilibrium are satisfied for each slice and moment equilibrium for the slipped mass as a whole This is achieved by taking moments about a point near to an equivalent centre of a circle When applied to circular slip surfaces the equations become identical to Bishop s method with parallel inclined forces and the calculated factor of safety is the same The benefits and limit
66. ordinates top of strata Point m Pore pressure distribution x Hydrostatic Piezometric Specified Ru O None Max suction head of water g Unit weight of groundwater 10 kN n Ru value GW surface S ingle Piezometers Original In the tabular input separate pages are given for each stratum To add a new stratum click on the Add stratum tab at the top of the dialog For each stratum enter a unique name and select the required soil type from the Material dropdown list Note by default Material 1 will be assigned to Stratum 1 Material 2 to Stratum 2 etc Select the required groundwater profile for this stratum choosing either Hydrostatic Piezometric Ru value or None If Ru value is chosen the value between 0 and 1 should be entered in the Ru value edit field If Hydrostatic or Piezometric is chosen the unit weight of groundwater and the maximum suction should be entered The required groundwater data should be selected from the dropdown lists for GW surface and Piezometers which will show any water tables and piezometer sets which have already been entered For a description of how pore water pressures are calculated for each groundwater profile type see Groundwater When entering stratum coordinates ground level should be defined at Stratum 1 with the soil layers below entered in order as Stratum 2 3 etc Note the limitations described in Defining multipl
67. ow and allow you to proceed It is possible to open more than one data file at any one time The file name is therefore displayed in the title bar at the top of each child window Oasys Ltd 2015 Input Data FA SLoPEman Titles Job Number Initials Last Edit Date 77101 60 J jl 26 Jun 200 Model Image Job Title Oasys Manual Example Subtitle Bishops Method Calc Heading Yariably Inclined Interslice Forces a Notes Calculation to show the main aspects of Copy SLOPE including loads piezometric profiles and a grid of circle centres Written by Slope version 19 0 0 0dev 4 2 1 New Model Wizard The New Model Wizard is accessed by selecting the File New Ctrl N option from the main menu or by clicking the New button on the Standard toolbar of Slope The New Model Wizard is designed to ensure that the basic settings for a model are consistent before any data is generated and that sufficient data has been supplied in order to perform a basic analysis The simple model created by the New Model Wizard can be adjusted or elaborated on via the Gateway after the wizard has been completed Cancelling at any time will result in an empty document Note The New Model Wizard can be accessed if and only if the Open file using New Model Wizard check box in Tools Preferences is checked 4 2 1 1 New Model Wizard Titles and Units The first propert
68. r all the slip circles analysed The following items are tabulated for each slip circle The x and y co ordinates of the Centre of Rotation The Radius of the circle The Slip Weight of the circle The Factor of Safety or Over Design Factor The Disturbing Moment and Restoring Moment of the circle Detailed results are provided for the slip circle with the lowest factor of safety The output provides details of the interslice and base forces in addition to the overall reporting of force and moment equilibrium Oasys Ltd 2015 ER Slope Oasys GEO Suite for Windows 5 2 1 1 Summary of Results This output summarises the results for all the slips analysed The following items are tabulated for each slip circle The x and y co ordinates of the Centre of Rotation about which Moment is taken The Radius of the circle for circular slips The Slip Weight The Factor of Safety or Over Design Factor The Disturbing Moment and Restoring Moment of the slip A column for comments provides the following information Comment Slip Type Definition Response Radius too large Circular Increase lateral extent of ground profile in X direction if required this message will inevitably be shown where the initial radius and increment method is used to define the circles to be analysed Horizontal ground Circular Non Where the location of the slip surface is entirely within an area Circular of horizontal ground Radius too small Circular
69. rces is reasonable and leads to sensible results An important case where errors can occur for horizontal or parallel interslice forces is that of interlock This arises in the case of a deep slip with a low factor of safety where the toe of the slip surface passes through a dense granular material Ifthe deep slip emerges at a steep angle and has a high mobilised angle of friction A where tan Ah tan 4 F Then the direction of the resultant force R on the base of the slice may be almost horizontal or even pointing downwards ground level 4 Wi EE a Section x WW R b Force Diagram In order to satisfy equilibrium of this slice the interslice force X must point upwards This direction is not consistent with the assumption of either horizontal or parallel inclined interslice forces Oasys Ltd 2015 RS Slope Oasys GEO Suite for Windows Variably inclined torces act in the correct direction to take interlock into account Horizontal Interslice Forces E Parallel Interslice Forces Wen Variable Inclined Interslice Forces In such cases the method of variably inclined interslice forces should be used Note Slope does not provide a warning when this problem may occur 3 2 1 3 Positioning of Slices Slope divides each slip mass into a number of slices The resulting slice boundaries are located at the following points at the left and right hand extent of the slip surface at the
70. re associated with the program rather than the data file All data files will adopt the same choices Preferences Numeric Format l i Company Info Engineering significant figures Decimal decimal places Page Setup Scientific significant figures Smallest value distinguished from zero 1e 006 Restore Defaults V Save file every 8 2 minutes Show welcome screen Begin new Files using the New Model Wizard Cancel Numeric Format controls the output of numerical data in the Tabular Output The Tabular Output presents input data and results in a variety of numeric formats the format being selected to suit the data Engineering Decimal and Scientific formats are supported The numbers of significant figures or decimal places and the smallest value distinguished from zero may be set by the user Restore Defaults resets the Numeric Format specifications to program defaults A time interval may be set to save data files automatically Automatic saving can be disabled if required by clearing the Save file check box Show Welcome Screen enables or disables the display of the Welcome Screen The Welcome Screen will appear on program start up and give the option for the user to create a new file to open an existing file by browsing or to open a recently used file New Model Wizard The user can create a new file through the new model wizard by checking the Begin new files using the New Model Wizard check box
71. s Ltd 2015 Input Data Radius can also be limited beyond which slip circles are not generated Tangent Surface A tangent surface is defined as a stratum boundary The actual circle stays just above the selected boundary ck cl tangent surface Note An additional soil boundary may need to be added to make full use of this feature For sloping strata boundaries as shown above Slope will calculate the shortest radius to the boundary for each centre and take this as the location of the tangent The calculated circle can therefore never cross the strata boundary line 4 3 10 4 Non circular slips If the slip surface type entered in the General Parameters dialog box is non circular selection of Data Slip Surfaces will open a table for entry of the non circular slip surface coordinates The program allows a number of slip surfaces to be entered and on analysis detail results of the slip surfaces giving minimum factor of safety is provided In the tabular input separate pages are given for each slip surface To add a new slip surface click on the Add Slip tab at bottom SS SLOPEman sld Slip Surfaces SEE A Add new slip Edit rename slip surface For each slip surface enter a unique name Oasys Ltd 2015 ER Slope Oasys GEO Suite for Windows Note 1 By default each slip surface will be named as Slip 1 Slip 2 etc the order of the default names will be maintained even if some slip surface i
72. s deleted or renamed 2 The slip would be extended either along the slope of the last segments or vertically depending upon the choice by the user made in the General parameters The slip surfaces can be entered in any order however before sending for analysis the pre processor will do the necessary editing depicted by the following image ea ee Terminated on The slip surface either projected or extended vertically intersection with ground as per the users choice 8 000 EEN Fee 6 000 4 000 2 000 D 2 000 4 000 6 000 20 00 1 oe 0 10 00 Following are the cases where the auto adjustment of slip would fail 1 Only 1 point exist for the curve 2 Curve completely outside 3 Inappropriate intersection with ground 4 On extension or vertical projection as per the choice by the user the slip does not intersect the ground surface In all the above cases the user will be prompted to manually correct the slip surface Non circular slip surfaces can also be entered using the graphical data view see Non circular Slip Surfaces Oasys Ltd 2015 Input Data A non circular 7 slip surface ground level ____ A ee c clay E sandstone In the example shown the coordinates entered would be A B C D There is no need to extend the coordinates of a non circular slip to the ends of the problem 4 3 11 Surface Loads The Data Surface Loads menu command opens this dialog or it can be opened by click
73. s part of the soil layer and left click with mouse button The point will then Snap to the closest location defined by the given snap interval Note You can follow the exact co ordinates of the cursor by looking at the given x and y co ordinates at the top left of the screen x 20 00 y 8 000 Editing strata 1 To edit the location of a point place the cursor over the point and click the right button This brings up an editing box as shown Coordinates x coordinate m y coordinate m 2 Amend the co ordinates as required and then click OK Note Points can be deleted by placing the cursor over the required point and clicking the left mouse button at the same time as holding down the Shift key on the keyboard 4 3 13 3 1 Defining multiple strata Material layers must be entered in descending order from the highest ground level The strata are numbered downwards from the ground surface which is represented by the upper boundary of Stratum 1 There is no lower boundary to the section and it is assumed that the lowermost stratum extends downwards indefinitely Note Each boundary should form a continuous line across the full width of the section If partial lines are defined the program will assume they extend horizontally to either side of the defined area This may cause overlapping of strata and such ambiguities should be avoided A warning will be given if partial strata are found before analysis Oasys Ltd
74. s shown Oasys Ltd 2015 Input Data a 4 3 13 5 Non circular Slip Surfaces Non circular slip surfaces are defined graphically in the same way as the Strata layers Add Non Circular Slip Draw Slip Adjust Slip Y Slope 19 0 SLOPEman Graphical Input Oem Beals elp Hz za B 2 Su Bia i a d 7 260 y 8 000 NonCirc Assigned material 990 100 5 400 mapanas Lol a a a a a a a a D 2 000 4 000 6 000 20 00 Seale x 1 321 y 1 321 For Help press F1 Tableview NUM D o D Ca H Fa j F Ee H x ground level ____ non circular Fi e al f 7 slip surface Pi Ka j a A ee f D se SB C j clay sandstone Adding a non circular slip surface The procedure for entry of a surface is as follows 1 Select the icon for addition of a non circular slip surface Oasys Ltd 2015 e Slope Oasys GEO Suite for Windows 2 Place the cursor at the location of a point which you wish to define as part of the soil layer and left click with mouse button The point will then Snap to the closest location defined by the given snap interval 3 To add new slip surface Select lt New gt from the Slip drop down box at the top of the window and repeat steps 1 and 2 Sip 1 NonCire The program provides an auto correct button which is applied to each slip separately The auto correct corrects the slip and gives the final slip that will be analysed The sl
75. s will be added to a set called Original This can be renamed as required Interpolation of piezometer data Interpolation is used to provide pore water pressures u for points at the base of each slice and at stratum interfaces to calculate the water force on the sides of each slice For points e Above the phreatic surface the piezometric level is taken to be the suction defined by the height of the point above the phreatic surface limited by a maximum specified value e Coincident with a piezometer then the value is taken at the location of the piezometer e Within or just outside the area of three piezometers the values are interpolated as follows For this purpose a point on the phreatic surface at the same x coordinate as the calculation point is added as a dummy piezometer with zero pressure The locations of the three nearest individual piezometers P1 etc are then mapped onto a triangular grid Oasys Ltd 2015 Input Data h level of water at each piezometer location DI Piezometers are located in the x y plane Linear interpolation is then used to create a plane of piezometric pressure from which the pressure for any individual point can be read Note If the program cannot interpolate due to lack of data then an error message will be given prior to calculation 4 3 7 3 Soil Suction The maximum suction sustainable by the soil can be specified in terms of head of water This is a positive term
76. stribution type is hydrostatic 4 2 1 4 New Model Wizard Ground Water Coordinates This page allows the user to define a single ground water table This page is activated only when the user selects the hydrostatic type of pore pressure distribution in Stratum Coordinates page New Model Wizard Ground Water Coordinates GW Profile 1 e Name Enter the name of the ground water profile e Coordinates Enter the coordinates which define the ground water profile 4 2 1 5 New Model Wizard Slip Surface Definition The last page of the New Model Wizard is the Slip Surface Definition window This allows the user to define the slip surface for which factors of safety are to be calculated Only circular slips can be defined in New Model Wizard Non circular slips may be defined via Non circular slips once the New Model Wizard is completed Oasys Ltd 2015 ER Slope Oasys GEO Suite for Windows 4 3 New Model Wizard Slip Surface Definition Circle certie specication Circle radius specification Singe O Gnd O Common point Coordinates of bottom left d a gad specified O Defined radi mi 0 giel Coordinates x m y mj 0 Tangent to stratum 1 Angle of rotation deg about bottom left of the gid Indal radius m Centres on gid Definition of centres about local axis Features of ond x drectionc y direction number number Clicking Finish completes the New Model Wizard and displays the graphical view of the
77. the ground surface A load has to be specified as either a permanent load dead or a variable load live For Partial Factor Analysis the user has to specify whether a load is favourable or unfavourable and for other analysis options this field is greyed out Reinforcement The Data Reinforcement menu command opens this dialog or it can be opened by clicking on the gateway Reinforcing elements are specified on the Reinforcement dialog Four types of reinforcement are available Ground anchors Rock bolts Soil nails Geotextile The data items which are not applicable to each particular type of reinforcement are greyed out when that type is selected from the drop down list Oasys Ltd 2015 Input Data e K ch1350 a crit_191 sld Reinforcement Data co ll Nailing Add reinforcement Name Nailing Type Soil Nail Layers Bond Length b Single Multiple Number 3 4 m o U t Level 97 5 Spacing m 1 premo axeln pscing m Bond strength kN m Offset from slope surface m 0 D Specify 0 Lenath L m Calculate from effective stress Top nail Bottom nail Angle from horizontal w 30 Capacity and Spacing Prestress kN 0 Out of plane spacing m Grout diameter mm Tensile capacity kN Plate capacity kN Material partial factors Select Undo Ar Delete Each set of reinforcing elements is given a name which is used to distinguish forces in
78. this document This example can be used by new users to practice data entry and get used to the details of the program Oasys Ltd 2015 Brief Technical Description Brief Technical Description Slope Slope is a program which is used for analysing the stability of slopes The program is also applicable to earth pressure and bearing capacity problems The methods are applicable also to rock slopes and waste heaps Summarised below are the main features of the program Analysis Methods Swedish Circle Fellenius Bishop s methods Janbu s methods Both circular and non circular slip surfaces can be analysed Circular surfaces are defined by a rectangular grid of centres and either a number of different radii a common point through which all circles pass or a tangent surface which the circle almost touches Non circular slip surfaces are defined individually The section to be analysed is represented by a series of soil or rock strata with boundaries defined by cartesian co ordinates The pore water pressure distribution can be varied in each stratum and can be specified in any of the 3 following ways e Simple hydrostatic pore pressure distribution below a phreatic surface e A user defined piezometric pore pressure distribution below a phreatic surface e An overall Ru value In addition a maximum pore pressure suction in a soil can be specified Submerged or partially submerged slopes can be analysed Soil strengths ma
79. tor of safety for that centre will be plotted Edit Graphics Settings If more than one slip surface is being plotted on the graphical output a legend showing colour intervals corresponding to the plotted range of factors of safety will be shown If there are many analysed circles by default only the 5000 with the lowest factors of safety will be shown To amend this or for more detail within a specific range of factors of safety left click on the plot legend or select Graphics Graphical Output Display settings A dialog box will be shown which allows the minimum and maximum factor of safety to be edited Oasys Ltd 2015 Analysis and Results Edit graphics settings FoS range to show on display Minimum 0 56 Maximum Contour interval on grid of centres Maximum number of slip circles to display Cancel The contour interval used in plotting contours of factors of safety is also editable from this dialog Ifa limited range is plotted a note will be added to the graphical output to indicate that not all the available results are being shown see example below The full range can be re displayed by clicking the Reset button on the Edit Graphics Settings dialog Factors of Safety gt 1 76 1 52 1 28 1 04 0 80 0 56 NOTE plotted range is a sub set of the results 5 3 1 2 Set Scale Selection of Set Scale Graphics Scaling Set Exact Scale or the 2 button allows you to set a
80. tress at which this transition takes place the strength relationship reverts to Mohr Coulomb For drained hyperbolic curve strength materials enter values for c and Do as follows We assume a relationship of T C 6 Dn C zo Ian Then 5t 80 Land De tan C on tan 4 c on far Cn o ant is the angle ao 0 andc value ofc when o Both A and ce are constants c can be calculated from c t o tan For undrained materials enter 1 A single value of undrained shear strength c 2 Alternatively a value of undrained shear strength c which varies linearly with elevation y Where c Co k y y c undrained shear strength at any elevation y C undrained shear strength at a specified elevation y k the rate of increase of shear strength with depth 3 A ratio of GJ for normally consolidated soils where p is the effective vertical stress which is calculated by the program at the point on the slip surface for each slice 4 A combination of 2 and 3 If both are selected then the higher value of strength is used 4 3 7 Groundwater The distribution of pore water pressures in the slope for each stratum can be defined in three ways 1 A phreatic surface with underlying hydrostatic distribution 2 A phreatic surface with piezometric pressures defined from individual piezometers 3 Specified values of Ru the ratio of pore water pressure to total overburden pressure The locati
81. w users to the Slope The requirements for data input are listed and linked to relevant sections of the main manual A new file can also be created via the New Model Wizard Please read the Data Input sections before attempting to create a new file No Operation Link 1 Open the program via the Start menu 2 On the Start up screen select the option to Create a new data Opening the Program file 3 Add the general file information into the Titles view Titles 4 Select the required Units for data entry and presentation of the Units calculations via the Data Units option from the program menu or via the gateway 5 Select the type of analysis direction and type of slip via General Data General Parameters 6 Select the analysis method and related data via Analysis Options 7 Enter the materials and their properties via Materials 8 Enter any ground water data This can also be defined via the Ground Water Data graphical input 9 Define strata Assign a material to each stratum Select the Strata type of pore pressure distribution for each stratum This can also be defined via Graphical Input view 10 Define slip surface data Specify the centre grid and the radius Slip Surface Definition for circular slips Enter the coordinates of the slip for non Oasys Ltd 2015 Step by Step Guide 5 circular slip Non circular slips can also be defined via the graphical input 11 Select the method partial factors via
82. y be represented by specifying e Cohesion c and or angle of shearing resistance 4 e Linear variations of cohesion with depth and or overburden pressure Horizontal acceleration of the slip mass to model earthquake loading can be included External loads e g due to buildings or strut forces in excavations can be applied to the surface The computed factor of safety can refer either to the soil strength c o tand where o is the effective normal stress along the slip surface or to the magnitude of the applied loads The loads can be specified to be causing the failure in the case of bearing capacity problems or to be preventing the failure as in the case of anchor forces Oasys Ltd 2015 Slope Oasys GEO Suite for Windows Index A Analysis menu 64 Analysis Methods Input Data 29 Assembling Data 17 Bishop s Methods _ 5 8 9 11 29 Horizontal Interslice Forces 11 Parallel Inclined Interslice Forces 13 Parallel Inclined Interslice Forces 12 Variably Inclined Interslice Forces 12 13 Bitmaps Adding to titles window 27 C Circular Slips 1 7 10 28 42 59 69 by centres 48 69 by radii 43 by surface tangent 43 Results 66 69 Common Point 1 42 43 59 Components of the User Interface 2 Contours Factor of Safety 69 D Data Checking 64 Input 24 Date 26 Defined Radii 43 Drained materials 10 32 E Errors Bishop s Simplified 10 11 Datachecks 64 66 Interlock 9 Rounding Errors
83. y page of the New Model Wizard is the Titles window This allows the user to enter the job details Oasys Ltd 2015 Slope Oasys GEO Suite for Windows New Model Wizard Titles and Units Job Number This can be any alphanumeric string By clicking the button the user can access the job numbers recently used Initials The initials of the user used on printed output Edit Date Today for new input when last edited for retrieved files Job Title The title of the job Subtitle The subtitle that this model relates to Calc Heading Specific to this model The above items are reproduced in the title block at the head of all printed information for the calculations The fields should therefore be used to provide as many details as possible to identify the individual calculation runs An additional field for Notes has also been included to allow the entry of a detailed description of the calculation This is reproduced at the start of the data output The user can select the desired set of units by clicking the Units button Oasys Ltd 2015 Input Data 21 4 2 1 1 1 Titles window Bitmaps On subsequent editing of Titles e g from the Gateway the layout changes to accommodate a bitmap image chosen by the user to aid subsequent identification of the data file The box to the right of the Titles window can be used to display a picture beside the file titles To add a picture place an image on to the c

Download Pdf Manuals

Related Search

Related Contents

Subject  Circuits en Camargue en voiture, à pied, à vélo  取扱説明書  Software for Parametrization of WEG Drives  Topcom BUTLER 3501 User's Manual  Mode d`emploi Kit Rénovation Phares G3000  

Copyright © All rights reserved. Failed to retrieve file