For many years, because of the bad rock condition and big ground stress, it limited the main opening and the speed of drift driving seriously, directly affect the mining methodically.

• 多年来,由于金川岩体条件较差,地应力大,严重制约井下主要开拓、采准巷道的掘进速度,直接影响矿山生产有条不紊的进行。