Numerical Evaluation on Dynamic Response of Existing Underlying Tunnel Induced by Blasting Excavation of a Subway Tunnel

Table 1

Material parameters.

Type	Natural density/kg/m3	Deformation modulus/GPa	Cohesiveness/kPa	Internal friction angle	Poisson ratio
Plain fill	1.96 × 10^3	0.035	15	10	0.3
Fully weathered basalt	2.1 × 10^3	0.055	17	35	0.27
Highly weathered basalt	2.6 × 10^3	0.075	20	45	0.25
Intermediate weathered basalt	2.7 × 10^3	9	460	65	0.2
Concrete C35	2.39 × 10^3	14	4500	62.2	0.3
Concrete C20	2.37 × 10^3	11	2600	60	0.3