不同开采条件下煤层应力演化及分区特征

Stress evolution and subarea characteristics of coal seam under different mining conditions

为了研究并确定不同开采条件下工作面前方煤体应力叠加重点位置,本文采用数值模拟建立力学模型,结合渝阳煤矿M7煤层实际地层进行模拟分析,获得了不同开采模式煤层及采空区的应力演化规律和分区特征。研究表明:单一区段开采时,采空区四侧煤壁均出现应力集中,采空区底板出现压实区。工作面前方煤体支承压力应力等值线呈现"W"型非均布状态,工作面中部煤体应力最大。上部一侧工作面采空时,本区段工作面开采上端头附近煤体出现显著应力叠加,工作面前方支承压力应力等值线呈现"L"型非均布状态,工作面前方上区段采空区侧煤体应力较大;当工作面上、下两侧均采空时,本区段上覆岩层来压剧烈,工作面及两侧煤壁均出现高应力,前方支承压力应力等值线呈现"U"型非均布状态,工作面上、下端头附近煤体应力叠加最为剧烈,深扩区积蓄能量大、范围广,需要严控冲击灾害的发生。

In order to study and determine the key control location of stress superposition of coal in front of working face under different mining conditions, using simulating and analyzing methods, the stress evolution and subarea characteristics are established based on the M7 coal seam in the Yuyang coal mine. The results show there is the stress intensification in the four sides of the goaf and in the compaction area of the goaf floor, after the single section is exploited. The abutment pressure presents the non-uniformly distributed state of ＂W＂ type and the stress in the middle of working face is the greatest one. When the working face at the upper side is mined out, the coal near the upper end appears to a significant stress superposition and the abutment pressure presents the non-uniformly distributed state of ＂L＂ type. When the working face at the both sides is mined out, the working face and the coal ribs appear the high stress superposition, the abutment pressure presents the non-uniformly distributed state of ＂U＂ type. The stress superposition of the upper and lower end of the working face is the most intense one. The high stress of deep extended region spreads widely and the disaster of this region needs to be strictly controlled.