Due to the large differences in physico-mechanical pro perties of composite strata,jamming,head sinking and other seriou......

在赵山渡引水工程许岙隧洞的开挖中，由于现场难以得到光爆专用炸药，只能利用直径25mm的乳化炸药卷，或者将直径32mm的药卷劈成条进行连......