承压煤层隐伏陷落柱突水机理数值分析

Numerical Analysis of Water Inrush Mechanism of Concealed Subsidence Pillar in Confined Coal Seam

以司马煤矿为工程背景,运用数值模拟的方法,分析流固耦合作用下承压煤层隐伏陷落柱突水问题.模拟结果表明:(1)工作面初次推进时,陷落柱内部及外边缘就产生塑性破坏;(2)工作面推进70m距陷落柱22.5m时,顶板与陷落柱塑性破坏区域贯通,形成导水通道,煤层顶板塑性破坏最大高度为37m.陷落柱内部孔隙水压力变化较明显,且陷落柱顶部孔隙水压力值分别为3.8MPa、4.2MPa;(3)煤层顶板沉降值最大为167.9mm,底板底鼓产生的竖向最大值为34.4mm.

Taking Sima Coal Mine as an engineering background,the water inrush problem of concealed subsidence pillar in confined coal seam under fluid-solid coupling is analyzed by numerical simulation method.The simulation results show that:(1)plastic failure occurs in the interior and exterior edges of the collapse column when the working face first advances;(2)when the working face advances 70 m away from the collapse column 22.5 m,the plastic failure area of the roof and the collapse column penetrates,forming a water diversion channel,and the maximum height of plastic failure of the coal seam roof is 37 M.The variation of pore water pressure in subsidence column is obvious,and the values of pore water pressure at the top of subsidence column are 3.8 MPa and 4.2 MPa respectively;(3)the maximum settlement value of coal seam roof is 167.9 mm,and the maximum vertical value of floor heave is 34.4 mm.