倾斜煤层长壁开采岩层运动特征及顶板控制

Strata behavior and its control of inclined coal seam face

采用了现场测试法 ,用相似材料模拟实验研究了倾斜方向岩层运动与围岩应力分布及用离散元法模拟围岩运动特征等方法 ,得到了以下结论 :( 1)煤层倾角导致岩层运动与破坏以及围岩应力分布差异很大 ;( 2 )采空区充填程度不同 ,沿工作面倾斜方向 ,下部充填较密实 ,而上部则处于空置状态 ,由于顶板支撑条件不同 ,从而导致顶板挠曲差异很大 ,经常出现上部断裂而下部完好的状态 ;( 3 )倾斜煤层开采导致的岩层运动比缓倾斜煤层强烈 .要求工作面支护既有足够的强度 ,更要确保其稳定性 .图 5 ,参 5 .

Strata behavior and control in inclined coal seam face are studied with the following three methods:field monitoring of strata behavior is carried out at a working face, model test on equivalent material is made along dip direction of face and both strata movement and stress redistribution are analyzed and described, overlying strata movement and fracture are modeled by discrete element method (DEM). The following conclusions may be drawn: (1) Inclined dip angle of coal seam leads to asymmetry of the movement and fracture of overlying strata as well as the abutment pressure distribution; (2) The gob is filled with caved debris differently; the lower end is fully packed, whereas the upper end is however in vacant condition. In the dip direction, the roof is supported by the caved debris quite differently, which results in differentiate roof deflection. The roof at the lower part will not break, but will certainly break at the upper face end, which leads to intensive strata movement in the upper end; (3) Roof movement is much more remarkable in inclined coal seam than that in gently inclined seam. It is therefore strongly recommended that the supports in longwall working face be set with higher stability to keep them sound.