房式采空区集中煤柱诱发动载矿压机理及防治

针对神东矿区石圪台煤矿31201工作面出上覆房式采空区集中煤柱回采动载矿压问题，利用现场实测和理论分析方法，通过分析超前支承压力作用下小煤柱保持稳定时的临界弹性核宽度、动载荷作用下工作面覆岩结构及支架载荷，对动载矿压的发生机理及防治措施进行了研究。结果表明：出集中煤柱期间，下煤层工作面覆岩的回转运动使上覆集中煤柱支撑宽度减小，若超前支承压力导致该部分集中煤柱及前方大面积小煤柱失稳，超前失稳煤柱覆岩的运动将使工作面覆岩受到动载荷作用，破坏工作面覆岩承载结构的稳定性，从而诱发动载矿压；提出了提前爆破集中煤柱的防治措施，并确定了爆破时工作面与集中煤柱间应满足的安全距离，在现场应用效果显著。

Mechanism and prevention of strong strata behaviors induced by the concentration coal pillar of a room mining goaf

In order to overcome the problem of strong strata behaviors at the No.31201 working face due to the overlying coal pillars of a room-and-pillar mining goaf at Shigetai Coal Mine in Shendong mining area，based on field observations and theoretical analysis，the authors studied the mechanism of strong strata behaviors and the prevention measures through analyzing the critical width of the elastic nuclear of a small pillar that remains stable under the advancing abutment pressure，and the strata structures under dynamic load and support load.The results show that during the period of working face moving out the area of the overlying coal pillars，the face strata rotation reduces the supporting width of the overlying coal pillars that support the overburden strata，if the advancing abutment pressure leads to the instability of those coal pillars and the small coal pillars at front large-area，the movement of the unstable pillars and overburden strata will lead to the face overburden under the dynamic load，which destructs the bearing structure of the face overburden，then the strong strata behaviors will occur.Hereby，the prevention measure is proposed as blasting the overlying coal pillars in advance.Also，the safety distance between the working face and the overlying coal pillars during the blasting is determined.The measures was proved to have obvious effect in the field application.