叠加开采应力及覆岩离层动态变化数值模拟

Numerical Simulation on Dynamic Changes of Stress and Overburden Bed Separation Concerned with Superimposed Mining

根据工程地质条件及其地应力实测结果,利用离散元法对工作面进行了采前岩体初始地应力状态数值模拟;沿工作面走向剖面上煤层(10,7煤)叠加开采应力场及其上覆岩层离层的动态变化数值模拟,再现了随着工作面推进应力场和离层动态发展的变化规律.并根据模拟结果进行岩浆岩及厚层砂岩能量积聚及动态破坏危险性分区预测分析.结果表明由于10煤先期开采,破坏了7煤煤系地层的原始应力状态,使部分岩层内有较大的应力集中;7煤回采破坏了岩浆岩的极限平衡拱根基,使其产生动力冲击失衡.这一现象恶化了7煤开采的覆岩应力条件,不利于7煤工作面的回采.

According to engineering geological conditions and ground stress measurement results,the Discrete Element Method was used to simulate initial ground stress state of rock mass before the production of working face and to simulate dynamic changes of ground stress field and overburden bed separation concerned with superimposed mining（coal 10,7） along strike profile of working face.This reconstructed the change rules and dynamic development of stress field and bed separation with the advancing of working face.In terms of simulation results,energy accumulation and risk zonation of dynamic failure for magmatic rocks and thick sandstone are forecast and analyzed.The results show that the initial stress of coal seam No.7 has a certain change because coal seam No.10 was exploited before,making the stress of some rock strata be concentrated.In addition,the exploitation of coal seam No.7 breaks the limited balance arch foundation of magmatic rock,resulting in an imbalance of dynamic impact.The phenomenon worsens overburden stress conditions for coal seam No.7,quite unfavorable for the exploitation of this coal seam.