Research and Analysis on the Influence of Small Clear Distance Drilling and Blasting Method on the Existing Tunnel Structure

Table 1

Material parameters.

Name of soil layer	Volumetric weight (kN/m^3)	Constitutive model	Elastic modulus (GPa)	Poisson ratio	Friction angle (°)	Cohesion (MPa)
Granite fracture zone	25.6	Modified Mohr–Coulomb	2.3	0.25	30	22
Moderately weathered granite	25.6	Modified Moore–Coulomb	4.72	0.19	37	35
C35 concrete	24	Linear elasticity	31.5	0.19	-	-