Analysis of Foundation Pit Support Selection and Design Problems in Deep Soft Soil Area
Table 5
Strength index of soil.
Layer no.
Layer name
Direct shear and quick shear
Direct shear and fast fastening
Unconfined strength qu (kPa)
Three-axis UU
Three-axis CU
Triaxial
cq (kPa)
φq (°)
ccq (kPa)
φcq (°)
ccq (kPa)
φcq (°)
ccu (kPa)
φcu (°)
c’(kPa)
φ’ (°)
②1
Clayey silt
11.6
16.8
16.2
18.1
—
—
—
—
—
—
—
②2
Clayey silt
7.6
26.9
10.2
31.8
—
—
—
—
—
—
—
④2
Mucky clay
8.5
6.7
15.3
13.0
20.3
8.3
0.2
18.3
4.7
16.0
4.5
⑥1
Argillaceous powder Silty clay
7.2
8.5
13.5
13.6
24.1
10.1
0.3
17.3
12.6
20.3
16.7
⑧2
Silty clay
7.3
8.1
14.4
16.5
—
8.6
0.6
19.0
15.1
24.0
19.9
The effective stress index of the consolidated undrained (CU) test results of layer ④2 in Table 5 is abnormal. See Table 6 for the relevant data provided by Zhejiang Institute of Geology and Mineral Exploration.
