The false top is the existence pole exchanges weak caving rock stratum between the coal seam and direct top. In the coal mining, it may often be happened.
伪顶是在煤层与直接顶之间存在的极易垮落的软弱岩层,在井下采煤工作面回采时,会常常遇到。
youdao
应用推荐
模块上移
模块下移
不移动