Vulnerability Analysis of Soft Caving Tunnel Support System and Surrounding Rock Optimal Control Technology Research

Table 2

Quality ranks of rock strength and quantitative scores.

Name	Quantitative data and description
Uniaxial compressive strength (MPa)	>80	80≤𝑆<60	60≤𝑆<40	40≤𝑆≤20	<20
Affecting the quality rank	Hard	Relatively hard	Medium	Relatively soft	Soft
Scores	2	4	6	8	10