Ⅱ类围岩浅埋段
layer of class Ⅱ shallow buried adjoining rock
Ⅳ类围岩
Surrounding rock of IV category
保护围岩
protect the surrounding rock
不良围岩
low-grade surrounding rock
采场围岩
stope wall rock
Surrounding rock
surrounding rock of working face
采场围岩控制
strata control around longwang face