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Frequently Asked Questions

1. Il 2 Q We have several systems connected to the same PC We were running only one of the systems so we shut off the ones we were not using Then we got an error message stating that the system we had left on was not responding It seems that we lost communication What is happening A A temporary loss of communication is normal when you either shut off or boot up any system unit connected to the same network Whenever a unit connected to the network is powered down or powered up the network goes into a re configuration mode during which no communication is allowed Depending on how many other units are on the network this process may take some time If the software checks connections while the process is going on you will get the not responding message If not no message will appear Should it appear simply wait a short period of time and then click the Retry button Everything should be back to normal Il 3 Q The Network LEDs are RED on the front panel of the LoadTrac ll unit There is no communication between the PC and the unit Our ID number is correct What else should we check A Probably the network communication cable gray cable is plugged into the Ethernet jack on the back of your PC instead of into the special black adapter that is plugged into the network communication card that we provided If you find that this is the case unplug the cable and plug it into the adapter on the card see picture below The LEDs should no
2. Be sure to make all weight measurements to an accuracy of 30 01 gm Before Test This section of the page is used to enter measurements made on sample trimmings before the test begins Trimmings Tare ID This is the name number or other identifying label of the container holding trimmings of the sample to be tested e g ICON1 Test2 CanA etc Trimmings Tare Weight This is the measured weight of just the container identified above Trimmings Wet Weight This is the combined weight of the container the tare and the trimmings before they are dried Trimmings Dry Weight This is the combined weight of the tare and the trimmings after they have been oven dried After Test This section of the page is used to enter measurements made on the portion of the sample that was tested the Specimen after the test is finished Specimen Tare ID This is the ID for the consolidation ring that held the specimen during the test typically just the word Ring Specimen Tare Weight This is the measured weight of just the empty consolidation ring identified above The measurement can be made either before the specimen is inserted or after the tested specimen has been removed from the ring Specimen Wet Weight This is the combined after test weight of the ring and the original wet sample Be sure that it does not include the weight of the filter papers and porous stones Trimmings Tare ID This is the label or name of the container usual
3. Cassagrande 1936 graphical method for estimating the preconsolidation pressure The compression index can also be estimated graphically through the e log s curve and is interpreted as the slope of the virgin consolidation curve There are also several empirical Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual O 2013 Geocomp Corp correlations that can be used to calculate the compression index directly based on soil properties e g LL and initial void ratio The table below gives some of these correlations Equation Reference Region of applicability C 0 007 LL 7 Skempton 1944 Remolded clays C 0 01wy Chicago clays C 1 15 eg 0 27 Nishida 1956 All clays C 0 30 eo 0 27 Hough 1957 Inorganic cohesive soil silt silty clay clay C 0 0115 wy Organic soils peats organic silt and clay C 0 0046 LL 9 Brazilian clays C 0 75 eg 0 5 Soils with low plasticity C 0 208e 0 0083 Chicago clays C 0 156e9 0 0107 All clays After Rendon Herrero 1980 Note eg in situ void ratio wy in situ water content VI SATURATION VI 1 Q Why is my final saturation value higher than 100 A This value is sensitive to several factors m The height and inside diameter of the ring m The before and after weight mass of the sample m The specific gravity of the sample If slightly inaccurate values for these qua
4. Help Project specin SE NR Read Table Consolidation Table Load Displacement Project Numbe Pressure Boring Number GB 0004 Project Nam Machine Test Number cons Location Boxborough MA Sample Number Gp 0004 Date of Test namo Depth 26 28 feet 2 On the Calibration Summary window select the sensor that you want to update from the list shown when the pull down button to the right of the top text field is clicked Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual 2013 Geocomp Corp 3 Calibration Summary m m ES Channel T Factor 0 1366791210971 N cnt Offset 35015 cnts Date Fri 24 NOV 2000 14 02 59 Cancel Download Apply Help 3 Click the Download button This will automatically transfer copy and save the current calibration parameters Factor and Offset for the selected sensor into the embedded controller 4 Repeat the above procedure for each sensor You should now see that the PC and LCD screen values match Ill 4 Q Does the data that is obtained through the dump feature include the machine calibration or is that raw data A The dumped data is raw data it does not include any correction IV PID SETTINGS IV 1 Q What are the effects and correlations between the PID values A The ICONP program uses a control technique that is very complex Consequently it is difficult to explain i
5. affect the overall rate at which the target load is reached but in somewhat different ways An increase in value increases the rate a decrease in value decreases the rate The possible value range for P Gain is from 0 5 to 5 and will change the loading time by about a factor of 3 from the lowest value to the highest Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual O 2013 Geocomp Corp While the default values 2 5 for P Gain and 0 2 for I Gain are appropriate for most soil types it may be helpful to increase the P gain to a maximum of 5 for a very soft soil specimen The I Gain should not be changed To change the P gain setting select PID from the Options menu to open the Load PID Settings window Change the Proportional Gain setting to a higher value click the Apply button and then close the window Il 5 Q If we set the maximum time for one loading step to 24 hours will the machine stop the step after it detects that the displacement reading has become constant We set 10 loadings for the test and now after almost 16 hours it reached number 8 Can you explain what criteria the machine uses to stop a certain step A The termination of a test step does not depend on the displacement reading reaching a constant value It depends on Tmin Tmax T100 Offset entered on the Consolidation Table and the T100 calculated by the control program The graphs below show a co
6. and load that file into the window We will call that file Test B Next you open a second ICONP control window and load into it a file for a test that was run on unit A We will call that file Test A Finally you copy the calibration parameters from the Calibration Summary in Test A and paste them into the Calibration Summary in Test A You now have a control program that contains the correct calibration parameters for running a test on unit A but those shown on the Calibration Summary will be different from those on the individual sensor Calibrate windows The parameters are not correct You have two LoadTrac ll units A and B You plan to run a test on unit A A file for a test run on unit B is a good template for the test but the calibration parameters in it are those for the sensors on unit B You open an ICONP control window and load that file into the window We will call that file Test B You decide to calibrate the sensors and use Test B to do it You go through the calibration procedure for each sensor and click the Calibrate button on each Calibrate window But you forget to click the Save button on each window before closing it Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual 2013 Geocomp Corp You now have a control program that has the correct calibration parameters on each Calibrate window and they will be different from those in the Calibration Su
7. resulting calibration factor is negative All that is needed is to remove the negative sign in the summary table and everything should work correctly Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual 2013 Geocomp Corp Calibration Summary Channel Displacement Facto 1 518821448e 00 mm cnt Offset 2405 cnts Date Sun 16 NOV 2008 22 00 11 Cancel Download Apply Help l 3 Q In many of our different test files the calibration values in the Summary Table and the values in each sensor s individual calibration table are not in sync Could you please explain which values the program uses and how to make sure they are correct A When running a test the ICONP software uses only the parameters that are shown in the Calibration Summary A mismatch between these values and those on the Calibrate window for a particular sensor can occur if the Calibrate window values have not been saved by clicking the Save button on that window To determine whether or not the Summary values are correct you need to know how the test was set up The two possibilities are described below The parameters are correct You have two LoadTrac ll units A and B You plan to run a test on unit A A file for a test run on unit B is a good template for the test but the calibration parameters in it are those for the sensors on unit B You open an ICONP control window
8. the load frame and the software factor 3 6498841x10 5 Does this factor seem to be off by a factor of two based on the other similar sensors you have calibrated A The calibration factor is correct The problem you describe can be caused by an incorrect setting for the polarity of the displacement sensor It has to be Unipolar not Bipolar Use the keypad and LoadTrac II LCD see illustration below to make the change as described in the following steps LoadTrac II Rev XX XX Xxx 1 Monitor 4 Setup 2 Position 3 Control 1 Use the arrow keys to select option 4 Setup on the LCD screen Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual 2013 Geocomp Corp From the Setup options select option 3 A D Setup From the A D Setup options select option 2 Channel 2 From the Channel 2 options select option 2 Polarity Of the two polarity options select Unipolar Finally turn off the LoadTrac Il and then back on for the changes to take effect O9 Ur BRUN l 5 Q Can I apply a new calibration factor to a previous test that have already run and get the correct results A Yes you can Open the ICONP program and load the file for the test you had already run You will need to replace the calibration parameters factor and offset that are shown on the Calibration Summary with the new ones There are two ways to do this 1 delete the original
9. 2 Q I am running a test Do I need to wait until the end of the test to see the results A You do not need to wait until the end of the test While the test is running 1 Go to the File menu 2 Select and click on Load 3 Go tothe Report menu You will be able to see the partial test results up to the point when you did the Load 4 Repeat the above steps as the test progresses Ill 3 Q noticed that the engineering readings on the LCD screen are different than the ones on the PC screen Are they supposed to be the same Did it affect the results of a test I just ran A First be assured that any mismatch of the engineering readings values between the LCD and the PC screens will not affect the results of a test that you run using the ICONP program A mismatch can occur if the calibration parameters that are shown in the Calibration Summary opened using the Calibration menu have not been downloaded into the imbedded controller of the LoadTrac Il unit However the software uses only the Calibration Summary values when it runs a test Consequently it is very important that these are correct To synchronize the LCD and PC screen readings you need to update the calibration parameters in the imbedded controller of the LoadTrac ll unit To do this follow the steps shown below l Bring down the Calibrate menu and select Summary ICONP C Program Files Geocomp Template for S DER File View Run PESEE Control Report Options
10. Be sure the load cell is not in contact with anything 2 Bring down the Calibrate menu and select Summary to open the Calibration Summary window Position this window beside the System Monitor window 3 Note the Load reading in counts on the System Monitor window top left text field 4 Replace the Offset value that is shown on the Calibration Summary window when Load is selected for the Channel choice with the Load reading in counts that is on the System Monitor window 5 Click the Apply button the Download button and then the Ok button to close the Calibration Summary window 6 You should now see in the System Monitor window that the vertical load cell reading in engineering units is within 0 025 of full capacity Note This zeroing process can be applied to other sensors such as a pressure transducer l 2 Q When I start a test the program gives me an error message that the calibration factor is too small cannot run the test checked the calibration summary table and all values for the calibration factors are there However the LVDT calibration factor has a negative sign Is this where the problem is and if so what do I do about it A The software does not accept zeros or negative numbers for the calibration factors in the calibration summary The most convenient way to calibrate the LVDT is to add gage blocks between the LVDT shaft and the stop When this is done the output signal decreases for each increment and the
11. ICON MS User s Manual 2013 Geocomp Corp Frequently Asked Questions Hardware I LIMIT SWITCHES l 1 Q The platen moves down at the beginning of the test until it triggers the lower limit switch Then the test stops and an error message appears on the screen indicating that the lower limit switch is on Why is this happening A This occurs if at the start of a test the load cell is registering a load that is greater than the target value for the first incremental consolidation step To ensure that this does not happen always zero the load cell before starting a test See Section 6 2 for the zeroing procedure l 2 Q During the test a controller error message appears on the screen telling me that a limit switch is on What should do A First click the OK button on the error message window to close the window What you do next depends on what caused the platen to reach a limit switch If the upper limit switch has been reached probably the test was started with the platen too high In this case you will have to lower the platen lower the load cell and restart the test Be sure to either delete the test file for the test that was not completed or rename it so that it is easily identified as an incomplete test If the lower limit switch has been reached probably the load cell had not been zeroed at the beginning of the test and was reading a load greater than the first incremental consolidation step To correct this situ
12. Trac ll system is similar to preparing the sample for a test performed manually The difference is that the results of measurements you will make during the preparation must be entered into the ICONP program by way of the Specimen page and Water Content page of the Properties Sheet Each consolidometer cell contains a stainless steel consolidation ring that is used to hold the sample Remove the consolidation ring Note the knife edge of the ring see picture at right This serves as a cutting edge while you are getting the sample into the ring but also it must be at the top of the sample during the test as the edge serves to center the sample within the cell If this is the first time the ring has been used measure its inside diameter and height to the nearest 0 1 mm 0 004 in using a precision caliper Type the results of these measurements into the Initial Diameter and Initial Height text fields on the Specimen page Weigh the ring to the nearest 0 01 gm and type the resulting value into the Specimen Tare Weight text field on the After Test section of the Water Content page If the ring has had previous use and you know its dimensions and weight you can use this information Lightly coat the inner wall of the consolidation ring with vacuum grease Your objective now will be to push the ring into your soil sample with as little disturbance to the sample as possible The sample must have a larger diameter than the inside diameter of th
13. al says that the Proportion Gain can be as high as 5 for soft soils and as low as 0 5 for stiff soils Also the Integral Gain should probably be set to 0 1 for very stiff samples What other values might be used and how are we going to decide on the best values to use Please clarify A It is possible to use any Proportional Gain P Gain value from 0 5 to 5 and any Integral Gain I Gain from 0 1 to 1 The Derivative Gain value of 0 should not be changed The rate at which a load is applied at the beginning of a step depends on both the P Gain and the I Gain lower value slower rate higher value faster rate The time to reach a target value increases by a factor of about 3 from a P Gain of 0 5 to 5 The table below gives general guidelines for P Gain settings Recommended P Gain Sample stiffness valie LOOSE VERY SOFT 5 0 MEDIUM SOFT MEDIUM 2 5 DENSE STIFF 0 5 In addition the following information may help you to decide what value will be best for your sample The graphs shown below are for loading curves generated during a test They were generated from data dumped into a file after the test Note that the time scale is not the same for the different soil types When possible the target load should be reached in less than 0 5 min Consequently a high P Gain setting is good for very soft soils It is easy to reach the target load value for stiff soils However as seen in the last two graphs the ta
14. arest 0 01 gm and type the resulting value into the Trimmings Tare Weight text field Now put the sample of trimmings into the container and weigh the combination of trimmings and container to the nearest 0 01 gm Type the resulting value into the Trimmings Wet Weight text field Finally dry the trimmings in an oven and again weigh the combination to the same accuracy as specified above Type the resulting value into the Trimmings Dry Weight text field The ICONP program will perform the necessary calculations to obtain the before test water content of the trimmings which should be the same as the before test water content of the sample Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual 2013 Geocomp Corp Software Il CALIBRATION ZEROING l 1 Q When I view the system before starting a test there is always an offset of about 0 005 kN 1 Ib Why There is no contact between the vertical load cell and specimen so why is there a small offset in the load and how can I make it zero A Between tests the load cell output can drift a small amount At best the no load condition will be in the range of 0 025 of load cell full capacity which translates to about 30 001 kN 0 25 Ib for a 4 45 kN 1000 Ib load cell If you observe a no load condition on the System Monitor window that is greater than 0 025 of full capacity use the following steps to zero the load cell l
15. ation zero the load cell see Section 6 2 for the zeroing procedure and then start the test again Il NETWORK COMMUNICATION Il 1 Q There is no communication between the LoadTrac Il and the PC What is going on A Check that the Node ID on the LoadTrac Il matches the one in the ICONP software program The Node ID on the LoadTrac II LCD is at the upper right corner as seen in the example below LoadTrac II Rev xx XX XXXX 1 Monitor 4 Setup 2 Position 3 Control Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual 2013 Geocomp Corp On the ICONP software program pull down the Options menu then select Hardware The Node ID will be shown in the top text field on the Hardware Setup window that will appear see sample window below If the IDs do not match change the Motor Node ID value shown on the Hardware Setup window to that on the LCD Click Apply then click OK sif ICON E Set up_Files ICON icon dat DAR File View Run Calibrate Control Report K92 9 Help z Units Project Specimen Water Content EXT Table PID X Hardware Setup Project Number Project Name Motor Node Location Boxboro MA Step Multiplier T106 mm step Date of Test 00 00 0000 Tester Control Loop Period 250 msec Digg Drainage Double Description Moist pale yellow brown E C Single Remarks ASTM D2435 Canes oh he
16. d 1440 120 1000 Time Before starting a test you should estimate how long it will take to reach the T100 condition Then when you fill in the Consolidation Table use a Minimum Duration time Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual O 2013 Geocomp Corp that is somewhat longer than your estimate During a step you can watch its progress using options from the View menu Choose the T100 option to find out the T100 value for that step When you know what it is you can change the T100 Offset value for that step to be 10 times the value Il 2 Q I am processing the data from the consolidation test we ran on a new load frame From the looks of the results it appears that when the data are dumped in engineering units the compression of the machine is NOT accounted for in the data that have been dumped Is this correct A Yes that is correct Compensation for machine compression is not applied to dumped data Dumped data includes only raw data values To view the corrected data bring down the Report menu and select Table You can than look at all of the corrected results by opening the various pages using the options on the View menu upper left corner of a page or the Page Down Page Up keys on your keyboard Il 3 Q I noticed that when running a test on a soft soil sample it takes a relatively long time for the load to reach the specified value How can I c
17. e a moist piece of filter paper trimmed to the sample diameter on the bottom of the sample Remove the bottom stone from the cell and place the sample plus ring onto it being sure that the knife edge of the ring is up Take care to avoid movement of the sample within the ring Now carefully place the combination of bottom stone and sample into the cell so that the stone fits into the recessed bottom of the cell The sample ring should be in the center of the bottom stone Place a moist piece of filter paper trimmed to the sample diameter on the top of the sample Install the centering ring and add the knurled nuts Tighten the nuts hand tight making sure that the sample is properly centered Position the top cap of the cell so that it is properly seated You have now completed the preparation of the sample Immediately after completing the procedure described above select a representative sample of the trimmings that were left after you pushed the ring into the sample and the trimmings that came from the ends of the sample You will need to put the trimmings in a container e g a large evaporating dish so that they can be dried The container is referred to as the tare The results of the measurements described below will be put in the text fields of the Before Test section of the Water Content page First mark the container with some identifying label and type this label into the Trimmings Tare ID text field Next weigh the container to the ne
18. e ring and be taller than the ring Set the sample on a flat surface and with your hand press the ring straight down into the sample taking care that it does not tilt to one side or the other As you press the ring down you may have to use a tool to trim away the excess soil outside the ring see picture above Do not discard the trimmings Alternatively with the right setup it is possible to extrude a sample directly from a tube into the sample ring With some care you can extrude 40 mm to 50 mm 1 6 to 2 0 inches of sample Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual O 2013 Geocomp Corp Once you have pressed the sample ring completely into the sample so that a portion of the sample is above the top of the ring use a wire saw to trim off excess material from the top and bottom of the sample so that the material is flush with the edges of the ring Take care to trim both ends of the sample as cleanly and evenly as possible Do not discard the trimmings When you have finished you should have a sample that has the diameter of the inside of the ring and the height of the ring Thoroughly clean any soil from the exterior of the ring Weigh the combination of ring and sample to the nearest 0 01 gm Now subtract the weight of the ring from the weight of the ring sample combination and type the result into the Initial Sample Weight text field on the Specimen page Plac
19. ectrical power problem such a power surge or brown out or due to inadvertent actions by an inexperienced end user You will need to revert back to the internal default values of your system by following these steps 1 Turn off the LoadTrac ll unit 2 Wait about 10 sec 3 Turn it back on and immediately press the ESC key on the keypad to reset everything back to the imbedded controller default values 4 Now go to your LoadTrac Il hardware manual In Section 2 1 4 Setup of the manual you will find a table of default settings for your system Go through each LCD menu and be sure the settings on the menu agree with those in the table If a setting does not agree change it to the one in the manual 5 If the Node ID number on your unit was changed because you are controlling more than one system with your computer set it to the value it was changed to The default value for LoadTrac ll is 65 Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual 2013 Geocomp Corp Ill 2 Q Can we turn off the PC while the test is running because this test is time consuming A No absolutely NOT But you can use other windows programs while the test is running and you can turn off just the monitor IV SAMPLE PREPARATION IV 1 Q This is our first time that we are preparing a consolidation sample Do you have any recommendation A Preparing a sample for testing in a Load
20. esults of the test change various settings for the report and edit the test data points Remember that each time you change or edit any item you will need to save the file and load it again V 3 Q Does the program automatically determine the overburden pressure the preconsolidation pressure and the compression Index A No those values are computed and determined by the end user as some may call for engineering judgment Then you need to go to Report Settings and manually enter them CONSOLIDATION TEST DATA SUMMARY REPORT S Report Settings nes el General Summary Coefficients Time Curves Machine Correction Corrected Uncorrected C Both Summary Vertical Axis mum C Displacement Strain C Void Rato Use Results at End of Increment C End of Primary C Spected Time 0 min Curves Vertical Axes C Displacement e Stain C Void Ratio Excess Pressure X M oe Denaro fers uow var tori yorar brown ait Mamona User Unt updete correct carotier fokra ond nade D before proceeding te ery tat OK Cancel Apply Help The overburden pressure is unique to your particular application and depends on what it is you are studying It is the pressure or stress imposed on a layer of soil or rock by the weight of the overlying material The preconsolidation pressure cannot be measured directly but can be estimated through the e log s curve Refer to
21. ew value click the Apply button and then close the window V REPORT V 1 Q How do I print my tables and graphs after a test has been completed A To print the table or graph for a completed test follow these steps l Bring down the Report menu 2 Select Table or Graph 3 Click on View at the upper left corner of the window that opens see illustration below then select print Next Page Previous Page Print Close V 2 Q After running a successful test we ran into troubles with the report We were not able to generate a report because all links on the report pull down menu are inactive Are we missing something or is the software not entirely installed A To make the links active parameters and data for a test must be loaded into the ICONP program so that they can be displayed on the various ICONP windows Go through the following steps to load a data file l First pull down the File menu Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual O 2013 Geocomp Corp 2 Next click on Load This will display a window that shows data files for tests that have been completed and for any test that is currently running Highlight the file name for the test you wish to load and then click Open 3 Finally pull down the Report menu You should now see the Graph Table Settings and Edit options all activated Using these options you can view the r
22. f T100 Tmin the program will wait until the time Tmin is reached continue an additional time equal to the T100 Offset and then automatically move to the next step T100 Tmin Condition for End of Step Tmax T100 Offset Example 1 The values of Tmin 260 min Tmax 1440 min 24 hr and T100 Offset 300 min 5 hr are entered by the user T100 calculated by the program is 30 min which is Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual O 2013 Geocomp Corp Tmin The step will last 60 min Tmin 300 min T100 Offset 360 min 6 hr which is less than Tmax 1440 min If T100 gt Tmin the program will continue the step an additional time equal to the T100 Offset then automatically move to the next step T100 gt Tmin Condition for End of Step Tmax T100 Offset LLL Star End T100 Example 2 The values of Tmin 260 min Tmax 1440 min 24 hr and T100 Offset 600 min 10 hr are entered by the user T100 calculated by the program is 120 min which is gt Tmin The step will last 120 min the calculated T100 600 min the T100 Offset 720 min 12 hr which is less than Tmax 1440 min If Tmax is reached before the end of the T100 Offset period the program will automatically move to the next step Tmax Condition for End of Step Tmax F T100 Offset Star End T100 Example 3 The values of Tmin 2120 min Tmax 1440 m
23. hange the rate at which the load is applied A The rate at which a load is applied is controlled by the PID Proportional gain Integral gain and Derivative gain parameters They are shown on the Load PID Settings window that is opened by selecting PID from the Options menu Both the Proportional Gain P Gain and Integral Gain I Gain affect the overall rate at which the target load is reached but in somewhat different ways An increase in value increases the rate a decrease in value decreases the rate The possible value range for P Gain is from 0 5 to 5 and will change the loading time by about a factor of 3 from the lowest value to the highest While the default values 2 5 for P Gain and 0 2 for I Gain are appropriate for most soil types it may be helpful to increase the P gain to a maximum of 5 for a very soft soil specimen The I Gain should not be changed To change the P Gain setting select PID from the Options menu to open the Load PID Settings window Change the Proportional Gain setting to a higher value click the Apply button and then close the window Il 4 Q How do increase the responding time for the loading in the consolidation A The rate at which a load is applied is controlled by the PID Proportional gain Integral gain and Derivative gain parameters They are shown on the Load PID Settings window that is opened by selecting PID from the Options menu Both the Proportional Gain P Gain and Integral Gain I Gain
24. in 24 hr and T100 Offset 1200 min 20 hr are entered by the user T100 calculated by the program is 300 min 5 hr which is gt Tmin The step will last 1440 min the Tmax value because 300 min the calculated T100 1200 min the T100 Offset 1500 min 25 hr which is greater than Tmax 1440 min Note These T values can be different for each step and the T values for subsequent steps can be changed EVEN during a test If going to a secondary consolidation is not needed and the T100 Offset value is set at zero each step could be quite short 60 min in Example 1 above with a T100 Offset 0 It is very unusual for a step to go as long as 24 hr and quite common for an entire test to take less that 24 hr Il 6 Q What are the recommended values for the maximum and minimum duration time for the consolidation tests Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual O 2013 Geocomp Corp A The recommended values for different types of soils are shown in the table below Recommended Duration Settings for a Consolidation Test Soil Recommended Max Type Duratiori Recommended Min Duration 1440 min 24 hours 30 min Silty 1440 min 24 hours 60 min Clay Plastic 1440 min 24 hours 120 min Clay Il 7 Q Is there a way to run the swell test using the existing iconp software A If your soil sample has a tendency to swell the
25. ly a large evaporating dish that will be used during the drying of the tested specimen Trimmings Tare Weight This is the weight of the container identified above Trimmings Wet Weight This the combined weight of the container identified above and the still wet sample plug the specimen that has been carefully removed from the consolidation ring after the top and bottom filter papers have been removed Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual 2013 Geocomp Corp Trimmings Dry Weight this is the combined weight of the container and the specimen after being oven The computer program uses information entered on the Water Content page to calculate the after test dry weight and the final water content of the sample In addition it uses information entered on the Specimen page to calculate the initial water content and the initial and final values of the void ratio the dry unit weight density and the saturation Note In order for the outcome of the ICONP data reduction to be correct be sure that accurate information has been entered on the Specimen page of the Properties Sheet as well as on the Water Content page To open the Specimen page click the Specimen tab on the Properties Sheet Be sure the actual measured 30 1 mm or 30 004 in diameter and height of the consolidation ring are entered not just the nominal values The Initial Sample Weight mu
26. mmary However it is the incorrect Summary values that will be used to run the test If you know or suspect that a test was run using a file with incorrect calibration parameters on the Summary window you can recover from the error Error Recovery Open an ICONP control window and load the erroneous test file into it You will need to replace the calibration parameters factor and offset that are shown on the Calibration Summary with correct ones If you are certain that the parameters on the individual Calibrate windows are correct simply click Save on each of those windows If you will have to enter new values manually there are two ways to do this 1 delete the original values and type the new ones into the text fields or 2 copy and paste the new ones For the second option you will need to open a second copy of ICONP and load the test file that contains the correct calibration parameters Finally save the file and reload it The new values will be applied to the processed data Note The raw data and the results of data reduction shown on the report pages will be changed The stress target values that were entered into the Consolidation Table page will not be changed l 4 Q used our calibrated gauge blocks to check our displacement sensor on the load frame It appears to give readings roughly one half the actual distance double checked that the calibration factor in cnt from the certificate you gave us is in both
27. n detail how the PID values are used In general terms as an applied load is reaching its target value the program periodically gathers information and adjusts the loading rate by using the information and the PID Proportional gain Integral gain and Derivative gain values Both the Proportional Gain P Gain and Integral Gain I Gain affect the overall rate at which the load reaches the target value but in somewhat different ways An increase in value increases the rate a decrease in value decreases the rate As the load gets close to the target value the P Gain functions to decrease the loading rate so that the target value is not reached too suddenly Keeping the loading rate constant would be like hitting the specimen with a hammer On the other hand l Gain functions to increase the loading rate throughout the loading process The values of these parameters that will produce the most rapid loading rate while preventing the target from being hit too rapidly differs for each soil type The default values of 2 5 and 0 2 for the P Gain and l Gain respectively work well for most soil types The graphs that are included in the answer to Q A IV 2 below help to show the effects of the P Gain and I Gain As can be seen the I Gain needs to be changed only for very stiff soils Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual 2013 Geocomp Corp IV 2 Q The software manu
28. n you must specify the first step as constant volume The program automatically increases the load to keep the volume constant Once the swell is under control It will then proceed to the next step that is higher than the swell pressure determined d ICONP C Carolyn MANUALS V8 MANUALS ICONP iconp template dat File View Run Calibrate Control Report Options Help Project Specimen WaterContent Read Table Test Parameters Consolidation Table 2 Constant Load Constant Load Constant Load Constant Load Constant Load Constant Load Constant Load Constant Load E Eg E E Es fe e E i Est Ent SD Ec en o Fer rst Jen s Ill GENERAL Ill 1 Q Can the software detect wrong values that are manually entered by the end user A Yes the software program detects any erroneous values that have been entered It also detects certain hardware malfunctions Examples include 1 Negative values for sample dimensions calibration factors and PID control parameters 2 Zero values for sample dimensions calibration factors except for offset value and PID control parameters 3 Wrong Node ID number Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual O 2013 Geocomp Corp 4 A malfunctioning sensor that it is giving an analog reading of either 0 the minimum value or 65535 the maximum value 5 Any load frame that is not on Ill
29. nsolidation curve and various quantities related to a test Note that the horizontal time axis is the square root of time for the first curve and is time on a logarithmic scale for the second curve The T100 value is shown on the second graph the time at U 10099 as almost 80 min Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual 2013 Geocomp Corp 0 1400 0 1500 D 0 1500 U 0 0 1600 0 1700 22 0 1800 Line 2 LLLILLPIILETILILELLELLLILITATX 0 1900 Dial reading in Line 1 gt D 0 1980 U 90 0 2000 0 2100 d N 1 15d N t 6 0 36 0 min 5 boo 0 2200 oN 0 2300 i en E E E E 30 35 40 10 15 20 29 Square root of time min 0 1400 C A B A D 0 1490 U 0 0 1500 x mi 0 1600 P Line 1 0 1700 Day Dj4D4 2 D 0 1790 0 1800 0 1900 Dial reading in 0 2000 D o 0 2090 Line s Pd t U 100 0 2100 0 2200 0 2300 woh oe ep ma 1000 10000 c Log of time min While the program is running a step it calculates the T100 value for that step When the T100 time has been reached the program checks the Minimum Duration Tmin Maximum Duration Tmax and T100 Offset values in the Consolidation Table I
30. ntities have been entered the program calculation of the final saturation value could be higher than 10096 For example the actual ring diameter might be 63 22 mm 2 489 in instead of 63 5 mm 2 500 in Similarly the height might be slightly different from the nominal value For the best results of data reduction we recommend that you carefully measure the dimensions of the ring using precision calipers This should have to be done only once but checking the values periodically is a good idea Be sure to make all weight measurements to 30 01 gm You will need to make an accurate measurement of the specific gravity or find an accurately measure value from some source If you do not need to have an accurate saturation value you can use the nominal ring dimensions and enter an estimated value for specific gravity being sure to specify this type of value using the pull down tab beside the Specific Gravity dialog box Alternative you can choose the option of Implied and let the ICONP program determine a reasonable value Note If for Specific Gravity you leave 0 in the text field to the right when the designation in the box to the left is Measured or Estimated the program will determine an implied value Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual 2013 Geocomp Corp Vil SWELL VII 1 Q In processing the information for the swell test noticed that the t
31. otal load needed to maintain the constant volume does not show up on the table printout The original applied load does but the only place it shows up is on the graph and from that it is difficult to tell the exact load that had to be applied Is there anywhere to find what the exact load went up to A To find out the load reached during the swell step you need to use the Dump selection in the File menu under File following these steps 1 Click on File then select Dump 2 Of the Dump options select Engineering 3 Dump will generate an ASCII data file that can be saved on your hard drive and then viewed using either a spreadsheet program such as Excel or a text editor such as Notepad VII 2 Q We are looking to do some swell testing on a clay sample according to ASTM 4546 method C My understanding is that this can be easily done with your equipment How can we do it 4 1 3 Method C The specimen is maintained at constant height by adjustments in vertical pressure after the specimen is inundated in free water to obtain swell pressure A consolida tion test 1s subsequently performed in accordance with Test Method D 2435 Rebound data is used to estimate potential heave A The swell test is an excellent example of how the use of automation in soil testing saves time and effort Instead of your having to apply increments of vertical stress as needed to prevent swell the fully automated LoadTrac ll will apply the required load to kee
32. p the height to within 30 005 mm 20 0002 in without any human intervention The following steps describe what you need to do to run the test l Prepare the sample as you would for a 1 D incremental consolidation test 2 Open the Consolidation Table page of the Properties Sheet Click on the pull down tab at the right of each Step Type text field and select the Constant Volume option 3 For each step enter a target stress value first column dialog boxes that corresponds to the effective overburden stress 4 Check all other entries on the pages of the Properties Sheet to be sure they are correct Be sure that the LoadTrac ll sensors have the correct calibration factors 5 Bring down the Run menu and click Start Vill WATER CONTENT VIII 1 Q How do I enter the correct water content information Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual O 2013 Geocomp Corp A You need to enter water content information on the Water Content page of the Properties Sheet opened by clicking on the Water Content tab The Water Content page is divided into two sections Before Test and After Test Note that the term Tare used in both sections of the page refers to a container itself not the tare value i e empty weight of the container The term Trimmings refers to the portion of the sample that will be dried either before the test begins or after the test is finished
33. rget value may not be reached smoothly To help this situation the I Gain or both the I Gain and P Gain can be decreased Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual 2013 Geocomp Corp Very Soft Soil Modulus 290 psi PID 0 5 1 0 PID 5 1 0 Medium Soil Modulus 4000 psi PID 0 5 1 0 PID 5 1 0 i Stiff Soil PID 0 1 0 1 0 PID 0 5 1 0 Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual O 2013 Geocomp Corp In addition a rule of thumb for response time is given in Section 6 0 of ASTM standard D2435 Standard Test Methods for One Dimensional Consolidation Properties of Soils Using Incremantal Loading Load application generally should be completed in a time corresponding to 0 01 t 100 or less For soils where primary consolidation is completed in 3 min load application should be less than 2 s To find out what the T100 value is for a step in a test open the Test T100 window by choosing the T100 option in the View menu at the beginning of the step As soon as the ICONP program has gathered enough information it will show the graphical determination of the T100 value on the window It will also list the T100 value in the Test Monitor window To change a PID setting click PID on the Options menu to open the Load PID Settings window Replace the default value with the n
34. st be the difference between the accurately measured 30 01 gm ring sample combined weight and that of the ring alone An accurately measured value of the specific gravity needs to be entered if you want accurate void ratios and degrees of saturation for the test If the plasticity of the sample is not known the Unknown designation must be chosen If the liquid limit and plastic limit are known their values should be entered so that they will appear on the report table produced by the software Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266
35. values and type the new ones into the text fields or 2 copy and paste the new ones For the second option you will need to open a second copy of ICONP and load the test file that contains the new calibration parameters Save using the Save or Save As option in the ICONP file menu the altered test file When you load that file again the new parameters will have been applied to the processed data Note The raw data and the results of data reduction shown on the report pages will be changed The stress target values that were entered into the Consolidation Table page will not be changed Il CONSOLIDATION Il 1 Q What settings do we have to change to obtain secondary consolidation properties A You need to increase the T100 offset value so that there will be time for the secondary compression of the particular soil type you are testing to take place The T100 Offset value see illustration below should be at least 10 times the value of T100 calculated by ICONP during a step This will give the program time to calculate a good value for the slope of the secondary consolidation curve line Project Specimen Water Content Read Table Consolidation Table Step Maximum Minimum T100 Stress Type Duration Duration Offset kPa min min min 1 6 894757889 Constant Load 1440 120 1000 Time 2 13 78951577 Constant Load 1440 120 1000 Time 3 27 57903155 Constant Load 1440 120 1000 Time 4 55 15806311 Constant Loa
36. w glow a solid green Geocomp Corporation 125 Nagog Park Acton MA 01720 Tel 978 635 0012 Fax 978 635 0266 ICON MS User s Manual O 2013 Geocomp Corp Il 4 Q While starting the test the machine will ask Position Platen When I press Yes the LoadTrac II should move the platen up until it just touches the load cell but how do I know whether the load cell is being touched The computer immediately asks me to Press OK when ready but am not aware of any other indication that the proper condition for starting the test has been reached A When you press Yes the green LED for Motor Up will come on you will hear the stepper motor in the load frame start to run and the platen will move up until the LoadTrac Il system senses a very small load that typically is less than 0 002 KN 0 50 Ib If the sample starts out very close to the load cell the upward motion of the platen may not be very noticeable As soon at the small load is sensed the green LED will turn off and the stepper motor will stop These are the indications that the condition for starting the test has been reached Ill POWER OUTAGE Ill 1 Q After an electrical power problem in our building it seems that the system is not working properly We suspect that the set up values on the embedded controllers are not correct How do we revert to the original set up values or default values set at the factory A The default values may change either after an el

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