After several years to jumbolter research,the hard rocks always present in the soft ones in the wall rock procedure using jumbolter,which results in changing the boring tool during the procedure.
经过几年对锚杆跟踪研究,发现锚杆
围岩作业
常遇到软岩
有
岩夹层
现象,造成施工过程经常更换
具
问题。