急斜煤层开采覆岩非均衡破坏机理分析

A Theoretical Analysis on Asymmetric Failure of Overburden in Steep Coal Mining

在急斜煤层开采条件下,由于岩层受切向力大于法向力、采空区上山方向端部煤体的抽冒以及采空区下山方向受滚落矸石的充填等因素的综合作用,采场上覆岩层一般呈现出非均衡破坏特点.急斜煤层开采岩层移动也不同于缓斜煤层开采呈现出的冒落带、裂缝带和弯曲带分区特征。本文基于急斜煤层开采岩层受力特点,根据岩层弯曲变形假设、岩体拉张破坏准则,分析了急斜煤层开采岩层的破坏形态及弯曲变形和滑移变形分布特征,提出了楔形破坏区和滑移变形区的岩层移动分区模型,并与相似材料模型试验和现场实测结果进行对比分析.急斜煤层非均衡破坏机理的研究为急斜煤层开采覆岩稳定性评价、地表移动预计等技术研究提供了理论基础.

In steep coal mining,due to the forces parallel to the plane of rock strata is greater than that perpendicular to the plane,and the synthetic action of upper wall side falling and the waste rock rolling filling in lower mining goaf makes the overburden failure an asymmetric characteristic.The strata movement distribution is different from the zoning with caving zone,fractured zone and bending deformation zone in gentle-dip coal mining.According to the strata load-carrying mechanism and in steep coal mining,based on the hypothesis of strata bending deformation and stretching failure criterion,this paper analyzes the overburden failure morphology and the distribution of strata bending deformation and slipping deformation in steep coal mining.A new theoretical zoning model of wedge-shaped failure zone and slipping deformation zone for strata movement analysis in steep coal mining is proposed and compared with equivalent material simulating and actual measurement.The theoretical model may be used to analyze the problem of overburden stability and surface subsidence.