1. a. A vane shear test was conducted in a saturated clay. The height and diameter of the rectangular vane were 4 in. and 2 in., respectively. During the test, the maximum torque applied was 230 lb-in. Determine the undrained shear strength of the clay.
b. The clay soil described in part (a) has a liquid limit of 58 and a plastic limit of
29. What would be the corrected undrained shear strength of the clay for design purposes? Use Bjerrum's relationship for l [Eq. (3.40a)].
2. Refer to Problem 3.17. Determine the overconsolidation ratio for the clay. Use Eqs. (3.42) and (3.45). Use s90 5 1340 lb/ft2.
3. In a deposit of normally consolidated dry sand, a cone penetration test was conducted. Following are the results:
|
Depth (m)
|
Point resistance of cone, qc (MN/m2)
|
|
1.5
|
2.06
|
|
3.0
|
4.23
|
|
4.5
|
6.01
|
|
6.0
|
8.18
|
|
7.5
|
9.97
|
|
9.0
|
12.42
|
Assuming the dry unit weight of sand to be 16 kN/m3, estimate the average peak friction angle, f 9, of the sand. Use Eq. (3.53).