巷道变形破坏
roadway deformation and failure
巷道变形破坏特征
course deformation characteristics
巷道变形与破坏
deformation and failure of roadways
爆破破坏分区
distinction of blasting crack zones
半煤岩软底巷道
Semi Coal and Rock Roadway with Weak Floor
半圆拱形巷道
semi-circular arched tunnel
扁宽断面巷道
roadways of flat and wide cross-section
标定巷道开掘方向
Marking the Direction of Laneway