An Analytical Calculation Method for Displacement Criterion on Tunnel Surrounding Rock Mass Stability

Table 3

Physical and mechanical parameters of surrounding rock mass graded from III to V.

Rock grade	Deformation modulus (GPa)	Cohesion (MPa)	Friction angle (°)	Poisson’ s ratio	Density (g/cm^3)
III	7.5	1.05	40.0	0.28	25.0
IV	3.0	0.35	32.5	0.33	24.0
V	0.65	0.08	25.0	0.40	23.0