金川二矿区多中段开采对地表岩移的影响研究

金川二矿区多中段开采曾引起了许多研究焦点，尤其是多中段开采导致的围岩变形和灾变问题最为突出。本文以多年地表监测的结果验证了多中段开采至结束期间并没有造成地表岩体变形的异常或突变。研究认为开挖的地质力学模型内所赋存的岩体应变能是一定值，开挖活动是能量耗散和转移的动态过程。因此，在构造应力影响的开挖力学模型中，不能采用外力边界条件而应采用位移边界条件。小步距开采-充填有利于避免大幅度的岩移发生，矿岩才保持了相对缓慢的低能量释放率的松动、破裂，是矿岩未发生大的灾变失稳的关键因素。最后指出，地表岩移速率大小主要与地下开采速度和采充比有关，在金川二矿地下开采速度和采充比基本保持不变的情况下，地表岩体移动、变形速率不会发生突变现象。

INFLUENCE OF THE MULTI-LEVEL MINING ON THE GROUND MOVEMENT IN THE JINCHUAN NO.2 MINE

Multi-level mining in the Jinchuan No.2mine had attracted extensive research interests. In particular,rock mass deformation and catastrophe was the most prominent one. In this study,surface monitoring results proved that no evident mutation or abnormal events occurred from the beginning to end of the underground mining in the levels 1250 and 1150m. In addition,displacement boundary conditions should be adopted in excavation mechanical model rather than the force boundary conditions because the strain energy is a constant and the excavation activities should be considered as an energy transfer and dissipation process in the model. The small scale mining and filling techniques are helpful to avoid large magnitude rock mass movement,thus,the surrounding rock mass did not occur catastrophic instability but exhibit loose and break features in the mining. Finally,it indicated that the displacement rates of the ground rock mass are mainly associated with the mining rate and filling quality. Thus,the catastrophe phenomenon of ground rock mass movement and deformation will not happen if these two factors remain the same in the future.