大柳塔煤矿多煤层开采覆岩变形破坏模拟研究

针对大柳塔煤矿远距离多煤层开采冒裂带发育及采动影响问题，通过相似模拟和数值模拟计算，系统研究了2个主采煤层开采过程中覆岩垮落、裂隙发育及地表沉陷规律。研究结果表明：浅部2-2煤覆岩主关键层破断后，顶板基岩会发生直达地表的整体切落现象，5-2煤一次采全高长壁开采冒裂带连通上部采空区，形成工作面涌水的导水通道；重复采动岩层与地表移动和变形值增大，非连续性破坏增加；采空区上覆岩体依据主应力分布可划分为双向拉应力区、拉压应力区和压应力区3个区，主应力状态对采动裂隙的形成、发育起着控制作用；采动影响与工作面几何参数密切相关，地表沉陷随着工作面斜长或采厚的降低而减小。研究成果对大柳塔及类似条件下的煤矿安全开采与设计有指导意义。

Simulation of Overburden Deformation-failure during Multi-coal Mining in Daliuta Coal Mine

Aiming at the problems of development of caving-fractured zone and mining influence，which occur during muti-coal seam mining in Daliuta Coal Mine，and through the similar simulation and the numerical simulation calculation，the overburden collapse，fracture development and surface subsidence law during the exploration of two main coal-seams were systematically studied.It is shown that rock strata of roof will directly fall from the surface after the broken of main overlying strata in shallow NO.2-2 coal seam.In the 5-2 coal seam，the caving and fractured zone caused by the once longwall and full-seam mining will develop into overlying goaf and form the water conductor of water inrush in working face.With the repeat mining strata，ground movement，and deformation value enlarged，the discontinuous damage of strata and surface increased.According to principal stress distribution obtained by numerical simulation results，overlying strata above goaf can be divided into three zones of two-way tensile stress zone，tension-compression stress zone and compressive stress zone.The principal stress state controls the formation and development of mining-induced fractures.Mining influence has a close relation with mining geometries，and surface subsidence value decrease with working face length and mining height reducing.Research results have important guiding significance for safety-mining and design in Daliuta and other coal mines with similar conditions.