Civil Engineering Reference
In-Depth Information
Exercise 4.4
The following results were obtained from a drained triaxial test on a soil:
Cell pressure (kPa)
Additional effective axial stress at failure (kPa)
200
200
400
370
600
540
Determine the cohesion and angle of friction of the soil with respect to effective
stresses.
Answer
φ
′
=
17°, c
′
=
10 kPa
Exercise 4.5
Undisturbed samples were taken from a compacted fill material and subjected to
consolidated undrained triaxial tests. Results were:
Additional axial
stress at failure (kPa)
Pore water pressure
at failure (kPa)
Cell pressure (kPa)
200
140
50
400
256
128
600
380
200
Determine the shear strength parameters of the soil.
Answer
c
′
=
0,
φ
′
=
19°
Exercise 4.6
An undrained triaxial test carried out on a compacted soil gave the following results:
Strain (%)
Deviator stress (kPa)
Pore water pressure (kPa)
0
0
240
1
240
285
2
460
300
3
640
270
4
840
200
5
950
160
7.5
1100
110
10.0
1150
75
12.5
1170
55
15.0
1150
50
The cell pressure was 400 kPa, and before its application the pore water pressure
in the sample was zero.
(i) Determine the value of the pore pressure coefficient B.
(ii) Plot deviator stress (total) against strain.
