Study on Seismic Response Characteristics of Shield Tunnel in Soil-Rock Combination Stratum

Table 1

Structure and stratigraphic physical parameters.

Material	Severe γ (kN·m^−3)	Modulus of elasticity E (MPa)	Cohesion c (kPa)	Internal friction angle φ (°)	Poisson’s ratio μ
Mixed fill	19.2	12	18.0	12.0	0.37
Silty clay	17.9	25	30.2	17.8	0.32
Limestone	21.2	6000	217.0	35.0	0.39
Bedrock	25.6	17200	—	—	0.20
C50 concrete	25.0	34500	—	—	0.20