Safety Assessment of Tunnel Shield Construction for Existing Adjacent Bridges
Table 1
Soil calculation parameters.
Soil layer name
Soil thickness (m)
Volumetric weight, γ (KN/m3)
Cohesive forces, c′ (KPa)
Angle of internal friction, φ′ (°)
(MPa)
(MPa)
(MPa)
Artificial fill
3.2
18.6
5.0
7.0
4.0
4.0
20.0
Clay
6.3
19.4
30.0
16.5
5.0
5.0
25.0
Silt
1.1
20.1
16.0
22.0
7.0
7.0
35.0
Full efflorescence argillaceous sandstone
1.6
20.9
30.0
21.0
10.0
10.0
50.0
Strong efflorescence argillaceous sandstone
36.8
21.0
90.0
22.0
15.0
15.0
75.0
Note. is the secant modulus obtained from the standard triaxial drainage test, is the tangent modulus of the lateral loading test, is the engineering strain unloading/reloading modulus. The above parameters are determined according to the survey report and engineering experiences.
