矿山开采覆岩应力拱演化规律研究

Study on Evolution Law of Stress Arch of Overlying Strata in Mines

根据京西矿区木城涧煤矿井下开采条件,利用离散元方法模拟了煤层开采过程中上覆岩层应力拱的演化过程,并对覆岩的真实破坏和裂隙发育情况进行了可视探测。模拟表明,随着开采面积的增大,拱顶向上部空间不断扩展,最终可稳定在开采煤层厚度的8倍左右范围内。现场采用钻孔摄像技术探测结果表明,覆岩裂隙发育不均衡,呈现破裂区与完整区交替出现的情况,裂隙上限与离散元模拟的应力拱拱顶位置比较吻合。

Based on the underground mining conditions of Muchengjian Coalmine in Western Beijing, the discrete element method was used to simulate the evolution process of stress arch for the overlying strata and the real fracturing of overlying strata and the conditions of crack growth were detected visually. The simulation results indieated that the vault of stress arch extended upward continuously along with the increase of mining area and finally reached the stable state in the range about 8 times as much as the mining thickness of seam. The detection results by the borehole camera showed that the development of cracks was non-homogeneous and the fractured zone and intact zone occurred alternately in the overlying strata, and the real upper bound of cracks was close to the vault of stress arch in the numerical simulation.