针对大倾角煤层走向长壁工作面开采矿压显现和围岩破断活动的复杂性.基于对不同类型大倾角煤层走向长壁工作面开采数值计算分析,开展了大倾角煤层走向长壁开采覆岩应力场形成与演化研究.结果表明:大倾角煤层开采围岩内发生应力重新分布,应力传递路线发生偏移形成三维空间应力拱壳,其演化形态可由判别系数确定,随着工作面推进,应力拱壳逐渐向外围岩层扩展,且非对称特性显现程度增加,沿煤层走向应力拱扁平率逐渐增大,沿煤层倾向应力拱扁平率逐渐减小,且应力拱最大高度位置不断向回风巷道一侧偏移.以上研究结果为大倾角煤层安全高效开采提供了理论依据.
The researches on formation and evolution of stress field of surrounding rocks have been made to improve the mining technology in steeply dipping coal seams.The results of study show that stress redistribution of surrounding rock occurs in steeply dipping seam mining,the routes of stress transformation shift and stress arch shell is formed in three-dimensional space.The evolution morphology of which could be determined by discriminate coefficient.With the face advancing,stress arch shell extends to the periphery rock and its non-symmetrical nature strengthened gradually.The flat ratio of stress arch increases gradually along coal seam when it decreases gradually along coal tendency,and the maximum height position of stress arch continues to shift to the side of return airway.The results above provide a theoretical basis for the safe and efficient mining in steeply dipping seam.