急倾斜煤层伪斜开采围岩变形规律数值模拟

Numeric Simulation of Surrounding Rock Deformation of Pitching Oblique in Steep Seam Mining

应用三维有限差分软件FLAC3D模拟伪斜开采,结合理论分析,揭示了基本顶和直接底的移动变形规律。结果表明,基本顶变形在伪斜方向上存在明显差异,上段持续时间长,速率增加快,破坏高度高,范围扩展到回风平巷外侧,下沉垮落区最终呈非对称拱形,拱顶约位于工作面中上段正上方;直接底在工作面处各分段处于底鼓不同阶段,下段开采压力集中释放,底鼓速率快速增长且稳定在较高数值,对底板破坏严重。以上原因在于矸石沿伪斜滚落堆积形成充填带,对工作面下段围岩变形起到抑制作用,而上段顶板在开采过程中悬露空间不断加大,膨胀卸压不受约束。

Numeric simulation of pitching oblique mining by software of fast lagrangian analysis of continua 3d,with theoretical analysis,reveal the mobile deformation regularity of main roof and floor.Deformation along pitching oblique are obviously different,the upper lasted longer,speed increased rapidly,damaged higher,and expanded tail gate outside,the sinking and collapsing area eventually is asymmetric arched,the vaults are above middle-upper of working surface;each part of floor under working face is in different stage of floor heave,mining pressure of the lower part focusedly release,floor heave rate grows fast and stabilizes at a higher value,badly damages the floor.All above are because the waste roll down along the pitching oblique and pile up to form a backfilling district,which inhibit the deformation of lower part of the working surface,however the bare space of upper roof enlarge unceasingly during mining,and inflate unconstrained to unload pressure.