Techniques for Progressive Failure Simulation of Hard Brittle Surrounding Rockmass: Taking the URL Test Tunnel as an Example

Table 1

Relevant physical and mechanical parameters of Lac du Bonnet granite [23].

The type of rock	Parameters	Values
LdB granite	Compressive strength of intact rock (MPa)	224
	Tensile strength of intact rock (MPa)	10
	Hoek–Brown constant	28.11
	Geological strength index GSI	90
	Internal friction angle	48
	Cohesion (MPa)	25
	Elastic modulus (GPa)	60
	Poisson’s ratio	0.2
	Compressive strength of rockmass (MPa)	128
	Tensile strength of rockmass (MPa)	3.7