ENGI 6723 Geotechnical Engineering II
Faculty of Engineering and Applied Science
S Kenny, Ph.D., P.Eng.
Fall 2008
Vane Shear Test
Due Date: Submit the lab report 2 weeks after completing the lab exercise
Vane Shear Test Procedures
1.
2.
3.
4.
5.
Measure the diameter and height of the vane.
Check the spring number.
Place the sample on the vane shear machine.
Push the vane into the sample.
Set the test speed of the machine, and zero the deflection dial (or take the initial deflection
reading).
6. Start the machine and rotate the vane until the deflection reading is constant
7. Repeat the test (steps 3 to 6) and calculate the average ell obtained from the two vane tests
differences.
8. Calculate the undrained shear strength (cu) based on the torque (T) at failure (Nm) for a
torque angle (θ, deg) at failure and spring constant (k, Nm).
Torque equation
T = kθ
where
k1 = 1.02×10-3 Nm/deg
k1 = 1.83×10-3 Nm/deg
k1 = 3.59×10-3 Nm/deg
k1 = 4.66×10-3 Nm/deg
Undrained shear strength
cu =
T
Kv
where
K=
π
v
D 2H 
D 
1+
× 10 −6


2  3H 
where
D ≡ vane width (mm)
H ≡ vane height (mm)
ENGI 6723 Vane Shear Test
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ENGI 6723 Geotechnical Engineering II
Faculty of Engineering and Applied Science
S Kenny, Ph.D., P.Eng.
Vane Shear Test
Fall 2008
Laboratory Report Format
Cover Page [5 points]
•
Report title, report submission date, laboratory test date, group number, student names
with corresponding student numbers
Table of Contents [5 points]
•
List of headings, tables and figures
Introduction [5 points]
•
State the laboratory test objective and governing engineering principles
Laboratory Procedure and Observations [10 points]
•
•
•
In your own words, using third person past tense, briefly describe the test procedure and
apparatus using concise paragraphs, logical bulleted lists, tables or figures.
Discuss any element that may have introduced induced errors or uncertainty.
State any test observation of importance.
Results [40 points]
•
•
•
Summarize raw test data and engineering data with supporting tables and graphs
Provide a detailed sample calculation for each specific computation required that
illustrates the logical progression from the raw data to the final engineering form. Use a
consistent system of units and show units in all calculations.
Present a qualitative and/or quantitative engineering discussion of the results in context
of what was expected. Identify any factors that may have affected the results, such as
precision, accuracy or errors, and suggest possible mitigation strategies in future tests.
Conclusions [20 points]
•
Summarize the test results, observations, and key findings including errors or
uncertainty and how the test results may have been affected
Appendix [5 points]
•
Include all lab data sheets, support documentation and calculations.
Presentation [10 points]
•
Effective communication, style and presentation are important attributes.
ENGI 6723 Vane Shear Test
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