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

Table 4

Allowable displacement according to different methods.

Rock grade	Allowable displacement (mm)
	Empirical method	Method by regulation	Method without plastic region	Method with plastic region
III	3.79	10–25	2.41	7.98
IV	10.73	20–60	8.36	23.76
V	120.00	30–80	18.76	54.71