VANE SHEAR TESTS WITH GEOTECH DATA …bartlett/CVEEN6340/Vane software...Vane software, version 1.4...

Vane software, version 1.4 2002-04-30

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USERS MANUAL

VANE SHEAR TESTS WITH GEOTECH DATA LOGGING

VANE: Evaluation of Vane test results. Choice of rod friction

GEOVING: Shear Stength Profile

22000011


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TABLE OF CONTENT Page Logging Software “VANE“, version 1.00e

1. Introduction 3 2. Logging of Vane Shear Strength Data With ”VANE” 4

2.1. Set-Up Menu 4 2.1.1. Start up screen 4 2.1.2. Location 5 2.1.3. Calibration codes 5 2.1.4. Vane number 6 2.1.5. File 6 2.1.6. View 7

2.2. Start-Sounding 8

2.2.1. Zero-reading 8 2.2.2. Generated file format (*.VIB) 12

2.3. Evaluating Shear Strengths / Generation of *.VB1 file 13

2.3.1. View 14 2.3.2. Rod friction 14 2.3.3. Next test 15 2.3.4. Shear Strength under Remoulded Conditions 16

3. GEOVING: Printing and evaluation of “VANE” test data files 17

3.1 Printing of vane tests and shear strength profiles 17 3.2 Change default values 21 3.3 Generating a shear strength file (*.VB1) 21


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1 INTRODUCTION Vane shear tests with the Geotech Electrical Vane Test Apparatus EVT 2000, are done with IBM compatible computers or with Geotech field computers/dataloggers Geologg and Geologg-PC with the DOS program VANE. The evaluation of the data and plotting are done with GEOVING. Once introduced in the soil layer to be tested, the vane is left for a period of time, generally defined in national standards (2 to 5 minutes in the Eurocode standard ENV 1997-3). Thereafter, it is rotated slowly, with a speed also defined in national standards (Eurocode: 0,1 to 0,2 degree in one second or 6-12 degree in one minute) and will force the clay trapped between the four plates of the vane to shear against the surrounding soil. By measuring the torque required to shear the clay and ultimately achieve failure, a value of the undrained shear strength is calculated. To measure the shear strength under remoulded conditions, please refer again to the national standards. According to the Eurocode: rotate the vane rapidly 10 turns after failure has occurred, in order to remould the soil at the failure surface. A new test is then immediately carried out under the same conditions as above. Thereafter, the sensitivity of the tested layer can be calculated. Vane shear testing is defined in national standards and it is recommended that the user is familiar with these. With instruments registering moment as a function of rotation angle, valuable information is obtained on the characteristics of the failure in the soil, as well as on the quality of the test itself. The torque registered, is the sum of two momentary torques: 1. the rod friction, and the case may be, friction between slip-coupling and vane protection,

and 2. the torque encountered by the vane in the tested soil. The first friction is measured with the EVT 2000 by means of an angular slip-coupling with 15 degrees of initial slip. Following these first 15 degrees, the sum of the rod friction plus vane torque is measured, until shear failure occurs. The undrained shear strength, is then calculated from the difference between shear failure and rod friction.


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2 LOGGING OF VANE SHEAR STRENGTH DATA WITH ”VANE” 2.1 Set-Up Menu 2.1.1 Start up screen When the computer is turned on and the programme VANE is executed, the screen displays the following start menu:

Fig 1: Start up screen Under the pop-up menu ”Location”, fill in: Date, Site number, Bore hole number, Coordinates, and the first test depth to be registered. Under ”Cal-codes” or calibration codes, fill in: Serial number of the instrument, Calibration code of the instrument, and Vane number (size). Under ”File”, fill in: Communication port on the computer used, Directory for storing the test, and whether the screen is in colour or in black and white. Under ”View”, you can display stored vane tests. Under ”Start-Sounding”, Start a new sounding. On ”ESC Quit”, end the sounding and terminate the programme. The following pages describe all these pop up menus.

You move between choices with the arrow keys on your key board and confirm your choice with ENTER. The chosen menu is marked, on a colour screen, in red or in dark grey, if you use a black and white screen. To activate the chosen menu, press ENTER.


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2.1.2 Location The chosen menu is Location (in red or dark grey). Activate by pressing ENTER

Fig 2: Location The upper square is marked in red or dark grey. YY MM DD: The software reads the date from the computer and recommends it. If you want to change it, press ENTER. The square is now blank. Write the new date and press ENTER. The square is again red or dark grey and the new date is registered. Go now with the arrows on the key board down and up and register similarly as for the date, Site number, new Coordinates and First test depth. If decimals are used, they must be separated with a dot and not with a decimal comma. For instance. the level 4.50 m cannot be written 4,50 m. Close the menu by pressing ESC. Go with the arrow key one step to the right until Cal-codes is marked and press ENTER. 2.1.3 Calibration codes

Fig 3: Calibration codes


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The upper square is marked in red or dark grey. Recorder no: Fill in the registration number of the Instrument Head EVT 2000. Once filled in, the registration number will be stored until it is changed. If you want to change the number, press ENTER. The square is now blank. Write the new number, press ENTER and the new number is registered. The square is again red or dark grey. Go with the arrow key down to Cal-code and fill in, as above, the calibration code for the instrument. If the results of the vane test shall have any relevance, the calibration codes should be of recent date, see Calibration of the Vane Instrument Head, page 15. 2.1.4 Vane Number Go with the arrow key down, to Vane no and register, according to the proceedings above, the size number of the vane used. The corresponding vane constants C are listed below see Appendix): Vanes, tapered lower end Vanes, rectangular ends Number Size (cm) Constant C (kPa/Nm) Number Size (cm) Constant C (kPa/Nm)

1 11,0 x 5,0 2,0 11 10,0 x 5,0 2,2 2 13,0 x 6,5 1,0 10 13,0 x 6,5 1,0 3 17,2 x 8,0 0,5

It is important that the vane dimensions are checked regularly to ensure that the vane is not distorted or worn. Close the menu by pressing ESC. Go one step to the right with the arrow key, until File is marked and press ENTER. 2.1.5 File

Fig 4: File name & Communication port The upper square is marked with red or dark grey.


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Com port = Com: Fill in the communication port used (normally, Com1 or Com2). If you want to change the pre chosen port, press ENTER. The square is now blank. Write the new port number and press ENTER. The square is now again red or dark grey and the new choice accepted. File Directory: It is recommendable to store all soundings from a same site, in a same directory, on your hard disk or on a disk. The directory to be used must however be created before the programme VANE is started. Colour (Y/N): Fill in whether it is a computer colour screen (Y) or black and white (N). Close the menu by pressing ESC. Go with the arrow key one step to the right, until View is marked and press ENTER. 2.1.6 View

Fig 5: View If the test to be viewed is stored in the pre chosen Directory, press ENTER. Otherwise, write the proper Directory and press ENTER.

Fig 6: Directory


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To choose the wanted sounding, go with the arrow keys right and left, up and down and confirm your choice with ENTER. 2.2 Start-Sounding The last screen is ”Start-Sounding”:

Fig 7: Start Sounding The programme is now asking for the Directory where to store the sounding data. If the suggested Directory is correct, enter a File name and press ENTER. If the test shall be stored in another Directory, go back and change the Directory under the File menu. Directories must be created before the programme VANE is started, in the hard disc drive of the computer or on floppy discs, as it is not possible to create directories, within VANE. All vane test data from one sounding will be saved in one file. When a file name and its location are chosen, start the sounding by pressing ENTER. 2.2.1 Zero-reading The computer reads the zero values of the instrument, i.e. angle and torque.


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Fig 8: Zero reading The zero for the torque should read 25 digital steps ± 10 (approx the same in Nm). If outside of this range, the full measurement range will not be read. The displayed example would not be acceptable! Please contact Geotech for assistance. The read zeros are then used as starting values. This emphasises the importance of having the vane turned to its anti-clockwise end position prior to any test (Part I). In the next picture, the depth of the first test is registered (in meters). Decimals are given with a dot.

Fig 9: Test depth When the test depth is registered, press ENTER. The screen displays torque and rotation angle axes. The software is ready to receive data from the Geotech Vane Test Apparatus EVT 2000. Start the test, by turning the on switch to position 2 for rotation, on the Instrument Head


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Fig 10: Vane test screen display The top bar shows the punched depth value and current angle, torque, and max. torque readings as well as time from start and rotation velocity. The rotation velocity varies in the various national standards. It is 0.1 to 0.2 degrees in one second in the Eurocode. The right hand side menu shows during the entire test: • PAUSE: Go with the arrow and press ENTER to make a pause in the test. • SOUND: Go with the arrow down to sound and press ENTER. Choose if the computer

should emit a sound signal during the test or a twinkling on the screen. This is a means to monitor that the computer is receiving data from the gauges in the Instrument Head.

• New Test: When the test on the actual level is completed, go with arrow down to New Test and press ENTER.

If you choose to interrupt the test and press ENTER, when PAUSE is marked, the screen will look as below.


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Fig 11: Pause function Right hand side menu, Start Vane is marked. The test will continue when pressing ENTER.

Fig 12: Testing The test is completed and the torque is displayed as a function of angle of rotation. From 0 to 5 degrees, the friction is building up along the extension rods, against clays (Standard model) or against connection pieces in the protection tubes (Eurocode model). From 5 to 20 degrees,


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the slip-coupling, with 15 degrees freedom, takes all the rotation and only the rod friction is recorded. Thereafter, the vane is loaded and the shear loading curve increases to a maximum torque of 47.30 Nm. Depending on the size of the vane used, this maximum torque is then converted to a shearing failure, which is the sum of the undrained shear strength of the soil layer and of the rod friction. The remoulded shear strength is then measured according to the national standards. According to the Eurocode, the vane has to be rotated rapidly at least 10 turns, after which a new test is carried out. When the test on this level is completed, go with the arrow key down to New Test.. Press ENTER, register the next test depth and continue the sounding. 2.2.2 Generated file format (*.VIB) The generated files have a *.VIB ending and are ASCII formatted. They contain each all tests done in a same sounding hole. The tests follow one after the other, split by “#” and a new depth “D” value, as seen in the following file with three tests. $ HB=2,HD=000121,HM=13,HK=1,HJ=1 HX=,HY=,HZ=,VS=3,IE=.97 HC=18 # AA=0.1,AB=.16,AD=2,D=5.1 AA=0.2,AB=.19,AD=3 AA=0.3,AB=.21,AD=4 AA=0.5,AB=.25,AD=5 AA=0.6,AB=.21,AD=6 ... AA=47.5,AB=3.33,AD=360 AA=47.6,AB=3.33,AD=360 AA=47.7,AB=3.3,AD=361 AA=47.8,AB=3.35,AD=362 AA=48.0,AB=3.34,AD=363 AA=48.1,AB=3.31,AD=364 # AA=0.1,AB=.00,AD=2,D=6 AA=0.2,AB=.00,AD=3 AA=0.3,AB=.00,AD=3 AA=0.5,AB=.00,AD=3 ... AA=80.8,AB=46.7,AD=200 AA=81.0,AB=46.43,AD=201 AA=81.1,AB=46.28,AD=201 # AA=0.1,AB=.00,AD=1,D=6.1 AA=0.2,AB=.00,AD=2 AA=0.3,AB=.00,AD=2 AA=0.5,AB=.00,AD=2 AA=0.6,AB=.05,AD=3 ... AA=50.2,AB=13.99,AD=114 AA=50.3,AB=14,AD=115 AA=50.5,AB=13.98,AD=115 AA=50.6,AB=14.01,AD=116 AA=50.7,AB=13.99,AD=116


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AA=50.8,AB=14.01,AD=116 AA=51.0,AB=14.03,AD=116 AA=51.1,AB=14.03,AD=117 The various parameters are as follows: HB = Number HD = Date, YYMMDD HM = Sounding method (13: Vane test) HK = Company number HJ = Object number HX = X coordinate (m) HY = Y coordinate (m) HZ = Z coordinate (M)

VS = Vane size IE = .97 HC = Serial number AA = Rotation angle in degrees and decimals minutes, resolution 0.5 second AB = Torque in Nm, resolution 0.03 Nm AD = Time from start in seconds, resolution 1 second D = Depth in meters, resolution 0.1 m

2.3 Evaluating Shear Strengths / Generation of *.VB1 files Under the View menu, several functions are available. When, according to the instructions above, a test is chosen, for instance G3.VIB, the screen looks like:

Fig 13: View existing file In this example the rod friction read from the graph or from the table values and the shear strength is thereafter calculated. In the menu on the right hand side, the following commands are accessible.


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2.3.1 View

Main menu 0-90 deg 90-180 deg 180-270 deg 270-360 deg

To change the range of displayed angles, move the arrow down and press ENTER. For instance if failure has occurred after 90 degrees, go to 90 - 180 degrees. To go back, move to Main menu and press ENTER. 2.3.2 Rod Friction The calculation of the rod friction, for all tests in a file or a sounding, is done with this function. The screen displays a cursor at the axes origin of the first test:

Fig 14: Evaluation of the rod friction Move the cursor from the origin up the curve with the arrow key. Stop the cursor exactly on the point just before the vane starts to be loaded and press ENTER. The programme is now reading the position on the cursor, calculates the shear strength and stores it in a File called G3.VB1, the value together with the depth of the first test of the sounding. Press the arrow key down and the next test in the file appears on the screen. Perform as above. Continue until no more tests are present on the file and the message END OF TEST appears.


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Press F10 and the calculations of the shear strengths in the tests in this sounding are completed with the information of the used vane. The results for all levels are stored in File G3.VB1. This File is then used for making profiles, in accordance with the format of the Swedish Geotechnical Society (SGF). 2.3.3 Next test

View Friction Next test Main date Change hole Quit

In order to display a test without calculating the shear strengths, this can be done with the ”Next test” function in the right hand side menu. Main date: If this function is chosen, the screen looks like:

Fig 15: View – Check location information The function allows a control of the general information on the sounding is correct: i.e. Date, Site number, Positioning and Instrument number, vane number, and Calibration code. Change hole: This command changes the sounding and the picture, Fig13 appears.


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2.3.4 Shear Strength under Remoulded Conditions The undrained shear strength of the studied soil is first calculated. The shear strength under remoulded conditions is calculated using the same vane constant and the recorded torque value. Input a slight different depth in the software if this second test is carried out. The sensitivity of the clay (in %) is the ratio between the undrained and the remoulded shear strengths.


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3 GEOVING: PRINTING AND EVALUATION OF “VANE” TEST DATA FILES This DOS program is very similar to the Geotech DOS Georit 3.40e software for CPT data. The first screen display indicates the version (1.41 E). Press any key to proceed.

Fig. 16: Software startup (“Tryck valfri tangent” means press any key) The following screen display is the principal menu, Fig 2:

Fig 17: Principal menu 3.1 Printing of Vane Tests and Shear Strength Profiles Printing of vane tests and of shear strength soundings is done with the first three functions in the menu, depending on the printer installed. All three give the similar menu, Fig 3


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Fig 18: Printing menu after pressing “1”, “2” or “3” Selecting “1 - Vane Sounding”, write the vane test file name preceded by its library name, or “enter” if the library name is correct. This will show the directory of vane test file *.VIB.

Fig 19: Library directory display, comparable to Fig. 6 After choosing a file, the R.L. Surface has to be defined. Thereafter, all the tests plots are generated and printed with the torque generated by the rod friction, the maximum torque, the vane type and the corresponding shear strength from the evaluation in VANE, Fig 14. Choosing the last line in Fig 3, “2 - Shear Strength” in Fig 3, all *.VB1 files in the chosen directory are displayed. Here again the R.L. Surface has to be defined prior to the printing of the shear strength profile, Fig 7.


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Fig 20: Printout of vane test and shear strength evaluation


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Fig 21: Shear strength profile, compiling all the interpreted values from one sounding


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3.2 Change default values Function “4” in the principal menu allows the user to change the default settings, Fig 6. A printer has to be defined for the proper running of functions “1” to “3” in the principal menu. To simplify the search and correct writing of the path to the vane test file, change “9 File directory”.

Fig 22: Change default values 3.3 Generating a shear strength file (*.VB1) Selecting “7” in Fig 2, displays the following screen, Fig 8, whereupon the same shear strength evaluation procedure as described in chapter 4 in the “VANE” software, Fig 14. The generated file is *.VB1.

Fig 23: Opening a vane test file, comparable screen to Fig 5 With the present software version, separate curves for undrained and remoulded shear strengths cannot be printed, nor can the sensitivity be calculated.

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VANE SHEAR TESTS WITH GEOTECH DATA …bartlett/CVEEN6340/Vane software...Vane software, version 1.4...

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