某金属矿地下开采地表沉降影响分析

Analysis of surface subsidence impact of underground mining in a metal mine

针对某金属矿向深部开采过程中遇到的地表沉降问题,通过建立该矿山全生命周期内矿体数值模型,研究随开采深度的增加,地表沉降对建(构)筑物和上覆岩层稳定性的影响。采用Midas数值模拟方法模拟矿体逐步开挖后,对地表沉降变形进行分析。研究结果表明,当矿体开采到-800 m中段时,在地表形成了近似圆形的沉降盆地,地表建(构)筑物的最大地表沉降量为16.77 mm,最大水平位移为-7.33 mm,地表最大倾斜为-0.041 mm/m,最大曲率为0.036×10^(-3)mm/m^(2),最大水平变形为-0.052 mm/m。地表沉降及变形值均不超过“三下”采矿规范限值,并且矿山采用充填采矿有效控制了井下采动对岩体的移动,地表及建(构)筑物不会出现明显的沉陷问题,对于该矿深部开采对地表沉降影响分析有一定的参考价值。

Aiming at the problem of surface subsidence faced by a metal mine in the process of continuous deep mining,establishes a numerical model of the ore body in the whole life cycle of the mine,and studies the influence of surface subsidence on the stability of the building(structure)and the overlying rock with the increase of mining depth.The Midas numerical simulation method is used to analyze the surface subsidence deformation after gradually excavating the ore body.The results show that when the ore body is mined to the middle part of -800 m,an approximately elliptical subsidence basin is formed on the surface.The maximum surface subsidence of surface building(structure)is 16.77 mm,the maximum horizontal displacement is -7.33 mm,and the maximum surface inclination is -0.041 mm/m.The maximum curvature is 0.036×10^(-3) mm/m^(2) and the maximum horizontal deformation is -0.052 mm/m.The surface subsidence and deformation values do not exceed the mining standard limit under buildings,railways and water bodies,and the mine adopts filling mining to effectively control the movement of underground mining on the rock mass,and the surface and building(structure)will not appear obvious subsidence problem,which has a certain reference value for the analysis of the influence of deep mining on the surface settlement of the mine.