为研究大倾角放顶煤采场围岩应力分布特征,以唐山矿0291工作面为背景,基于弹塑性极限平衡理论分析了大倾角放顶煤采场围岩应力分布特征;根据工作面赋存条件,采用FLAC3D软件模拟了工作面推进至不同位置处的围岩应力变化。研究结果表明:大倾角放顶煤采场围岩应力分布特征理论表现为塑性区支承压力与其距煤壁距离成正相关,峰值为KγH,0291工作面应力峰值点位于工作面煤壁前方10m左右位置处;工作面顶煤与顶板会发生较大范围的塑性破坏,上覆岩层破坏范围约为60m,期间顶煤会发生多次压剪破坏,使得顶煤破坏程度升高,粒度减小,具有较好的冒放性。

In order to study the stress distribution characteristics of the surrounding rock in the steep angle caving coal mining area,taking the 0291 working face of Tangshan Mine as the background,the distribution characteristics of the surrounding rock stress in the steep angle caving coal mining area are analyzed from a theoretical level by calculating the support pressure distribution in the elastic-plastic zone.At the same time,numerical simulation calculations were conducted using FLAC3D software based on the actual occurrence conditionsof the mining area and the mechanical parameters of the coal rock block after the working face was advanced100 meters.The research results indicate that the theoretical expression of the stress distribution characteristicsof the surrounding rock in the steep angle caving coal mining area is that the support pressure in the plasticzone is positively correlated with its distance from the coal wall,with a peak value of KγH.The peak stresspoint of the 0291 working face is located about 10 meters in front of the coal wall of the working face;The top1coal and roof of the working face will undergo a large range of plastic damage,with an advanced damage rangeof about 60 meters.During this period,the top coal will undergo multiple compression and shear failures,resulting in an increase in the degree of top coal damage and a decrease in particle size,indicating good caving performance.