Influence of Small, Clear Distance Cross-Tunnel Blasting Excavation on Existing Tunnel below

Table 2

Physical and mechanical parameters of finite element calculation.

Medium	Elastic modulus E (GPa)	Poisson’s ratio µ	Bulk weight (KN/m^3)	Cohesion C (MPa)	Friction angle φ (°)
Grade IV surrounding rock	22.75	0.32	22	0.5	30
C30 formwork concrete	31	0.15	25	2.5	53.8
C30 shotcrete	25	0.15	22	2.5	53.8
Φ25 bolt	200	D = 2.5 cm