沟谷坡角对浅埋煤层工作面矿压影响的研究

Study on Influencing Laws of Gully Slope Angle on Ground Pressure of Working Face in Shallow Coal Seam

针对神东矿区活鸡兔井在沟谷地形下工作面动载矿压灾害问题,通过力学分析和物理模拟实验,就沟谷地形的坡角对工作面动载矿压的影响进行了研究.结果表明:当工作面推进到覆岩主关键层被侵蚀的沟谷地形时,临近上坡面的主关键层破断块体侧向水平挤压力作用较小;随坡角增大,主关键层上覆岩层载荷逐渐增大,块体结构不能满足砌体梁的"S-R"稳定条件而滑落失稳,使亚关键层结构块体承受的载荷迅速增大,导致工作面活柱急剧下缩片帮冒顶严重而发生动载矿压;当坡角小于15°时,工作面一般不会发生动载矿压显现灾害事故.理论分析和模拟结果与现场实测吻合良好.

Considering the dynamic strata pressure accidents happened in the working faces while mining under gully terrain in Huoiitu coal mine of Shendong mining area, we have re- searched the influence of gully slope angle on dynamic strata pressure of working face in shallow coal seam in this paper, by using the methods of mechanical analysis and physical simulation experiments. The results show that when the working face advances under the gully terrain where the primary key strata has been eroded, the lateral horizontal compression formed by fractured blocks of primary key strata nearby the uphill face is relatively small. As the slope angle increases, the overlying strata load of primary key strata increases gradually, and instable sliding of the block structure will happen as the structure can＇t he met the ;S-R; stability condition of voussoir beam structure, which will make the load on the blocks in inferior key strata increase rapidly, and resulting in sharp drop of mobile columns in the face, serious side fall roof caving of coal wall, and even dynamic strata pressure phenomenon. When the slope angle is smaller than 15°, there is nearly no dynamic strata pressure accident happened in the faces. Theoretical analysis and simulation results fit the field measurement well.