浅埋近距煤层采空区覆岩移动规律相似模拟

Similar simulation on strata movement of gob in shallow-contiguous seams

浅埋近距煤层采空区坚硬顶板覆岩与煤柱破坏易导致动力灾害,同时会影响顶板涌水溃沙和地表沉降,为确保此类矿井的安全高效开采,结合冯家塔煤矿1402综采工作面实际,对该煤矿进行了煤柱破坏与覆岩移动规律的物理相似材料实验模拟研究,试验是以1-1采区的开采为模拟对象,模拟在工作面长度为270 m的单一走向长壁开采后,上覆岩层的移动和变形规律。研究结果表明:随着浅埋近距煤层采空区的增大与时间的推移,开采时大面积来压是由于保护煤柱逐渐被压垮引起覆岩大面积冒落,致使近距煤层之间采空区导通,垮落从直接顶开始,逐步扩散至地表,上覆岩层的运移以垂直为主,水平运移并不明显,形成梯形状下沉,上部煤层开采后其覆岩关键层破断块体结构的稳定性是影响下部煤层开采时工作面矿压显现强烈程度的重要因素。

Hard roof and coal pillar failure may lead to dynamic disasters in gob of shallow-contiguous seams,will also affect roof leaking water and sand,surface subsidence.In order to ensure the safe produce of such mine,we made this similar simulation study on strata movement of gob and coal pillar failure in shallow-contiguous seams.The experiment is based on 1-1 district,the length of the work face is 270 meters,after single longwall mining,the movement and deformation of the overburden.The result show that： with the goaf increasing and arrow of time,while mining,a large area pressure caused by the gradually breaking of protection pillar,causing the gob of contiguous seams conduction.The deformation begins from the immediate roof to the surface.The movement of overburden is almost as vertical migration,forming the trapezoid-shaped sink.As the up seam has mined,its key stratum stability will affect its down seam mining.