Solution of Strain-Softening Surrounding Rock in Deep Tunnel Incorporating 3D Hoek-Brown Failure Criterion and Flow Rule

Table 1

Calculation parameters [8].

Quality of rock mass		(m)	(MPa)							(GPa)	(GPa)
Average	0.25	5	80	0.0039	0	0.51	0.53	2.01	0.34	9	5
Very poor	0.3	5	25	0.0039	0.0019	0.55	0.6	1.7	0.85	5.7	5.7