煤层群下保护层开采保护范围的数值模拟

Numerical Simulation of Protection Scope When Lower-protective Layer Mined in Coal Seams

为确定煤层群下保护层开采上部被保护煤层的保护范围,结合金佳矿一采煤工作面保护层顶底板煤岩层的物理力学参数和地质特征,采用FLAC3D软件模拟下保护层开采中被保护层的应力场及变形场的变化过程,得出保护层的保护效果;并根据保护层开采的应力卸压保护准则和变形保护准则,确定保护层沿倾向和走向的保护范围。结果表明,由于岩性及岩层结构的影响,通过数值模拟确定的各被保护层的保护范围与按照卸压角确定的保护范围有一定差异;分别用现场考察与数值模拟这2种方法所确定的下保护层保护范围基本一致。

Aiming at delimited the protection range rising from lower-protective layer mined in coal seams, basing on the geological properties and the physico-mechanical parameters of roof and floor rock strata of protective layer of a certain coal mining working face in Jinjia mine, the changing processes of stress field and deformation field of protective layer during exploiting lower-protective layer were simulated by FLAC3D software. Then, the protecting effect of protective layer was got. According to the protection rule of the deformation and stress-relief in exploiting protective layer, the inclination and strike protection scopes of protective layer were located. The results show that the protection scopes of protected coal seams got with numerical simulation are different from those estimated with relief angle because of influences of rock nature and rock strata structure, and that the protection method of practical test and the rock nature are basically scopes of lower-protective layer located by the consistent with the numerical simulation.