They may also transfer the thrust to sound rock at a low elevation . 他们也可以将推力传到高程较低的良好岩石上。
2.
Open type , whole section rock tunneler is mainly used in the construction of sounding rocks with relatively better geological stratum conditions 摘要敞开式全断面岩石掘进机主要用于围岩相对较好的地质地层的施工。