jumbolter

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.

经过几年对锚杆钻机研究,发现锚杆钻机在围岩作业中遇到软岩中有硬岩夹层现象,造过程经更换钻具问题。