急倾斜下保护层倾向保护范围数值模拟及验证

Simulation and validation of mining below protective layers in a steeply dipping coal bed

基于保护层顶底板煤岩层的物理力学参数和地质特征,利用有限元软件ANSYS生死单元模拟下保护层开采,观察开采后的被保护层应变、应力场的变化情况,根据保护准则确定倾向保护范围。结果表明,下保护层开采急倾斜煤层沿倾向下部边界的卸压角为88°。同时,在实验现场通过布置压力孔,观测压力变化情况来分析确定保护范围沿倾向下部边界的卸压角为86°。对比分析数值模拟和现场实验的结果,在现场施工不确定因素影响下,最后确定下保护层开采急倾斜煤层沿倾向下部边界的卸压角为86°。

Based on the geological properties and the physico-mechanical parameters of roof and floor rock strata of protective coal layers, we use the birth and death unit of ANSYS to simulate cutting the covering layer, and to observe the process of change in the stress and deformation fields of protected layers. The simulation result shows that the downward pressure-relief angle along the inclines of steeply dipping lower protective layers is 88°. Simultaneously, we create some holes to measure pressure and observed their transformation. To ensure the downward pressure-relief angle along the incline of protective areas of the protective layers is 86°, we monitor the changing pressure situation. Comparing the result of the numerical simulation and the practical test values, under the influence of many dubious factors, we conclude that the ideal downward pressure-relief angle along the inclines of steeply dipping lower protective layers is 86°.