金属矿充填开采岩体移动对竖井围岩的变形破坏

Shaft deformation and failure due to rock mass movement induced by underground backfill mining of a metal mine

采用数值模拟和地质力学分析的方法,对甘肃金川二矿区地下开采条件下,#14行风井变形破坏问题进行了研究,研究结果表明:#14行风井位于地下开采引起的岩体移动盆地的拉张区,受岩体移动变形影响剧烈,地下开采已经成为了影响竖井安全稳定的主要因素;无论是富矿开采还是贫矿富矿联合开采,竖井井壁的位移和应力分布规律大体相同,其大小与分布特征受断层影响突出,断层所在的部位仍然是竖井井壁的脆弱部位;地下开采引起的#14行风井的破坏是以穿过井筒的断层出现活化为触发因素,以井壁发生错动、破裂、冒落为主要形式的断层效应的集中体现,这也将成为现阶段生产条件下竖井可能再次发生变形、破坏的模式。

The vertical shaft plays an important role in underground tunnel mining mines. However, few attempts have been done on the deformation and failure mechanics of shafts suffering from rock mass movement in metallic mines undergoing mining activities. Numerical simulation methods and geomechanical methods are applied in the study of deformation, failure and stability of the line No. 14 ventilating shaft in Jinchuan No. 2 Mine under the conditions of different kinds of mining design. The results show that the shaft is seated in the scope of the depression induced by the underground mining, and the displacement of rock mass keeps increasing. Therefore the underground mining is the main factor for the safety and stability of the shaft. Moreover, whether mining of the rich ore body or combined mining of the rich ore body and lean ore body, the distribution regularities of displacement and stress of the shaft are similar, and the section of the faults is still the vulnerable zone of the shaft in which it influences the size and distribution of the displacement and stress greatly. Consequently, it is the faults which cross the shaft and lead to reactivation due to underground mining are the trigger factor, and the rock mass movement, rupture and fall are the primary form of the shaft deformation and failure mechanism, and this kind of fault effects will be aroused again in the future under the present circumstances of mining.