链臂锯切顶卸压小煤柱留巷开采围岩稳定性分析

在大同矿区"三硬"煤层条件下,随着浅部煤炭资源的日益枯竭,采矿活动不断走向深地,地应力逐渐增大,塔山煤矿8311工作面和8312工作面间仅留设6 m小煤柱,2312巷会遭受两工作面的重复采动,为保证两工作面重复采动影响下巷道的围岩稳定性,同时保证煤炭采出率,采用同煤集团自行研发的链臂锯进行机械切顶,以达到顶板弱化效果....

Analysis on stability of surrounding rock in small coal pillar roadway with chain arm sawing

Under the condition of "three hard" coal seam in Datong mining area, with the gradual depletion of shallow coal resources, mining activities continue to go deep, and the ground stress gradually increases. Only 6m small coal pillar is left between 8311 and 8312 working faces in Tashan Coal Mine, and 2312 roadway will suffer repeated mining of 8311 and 8312 working faces. In order to ensure the stability of surrounding rock under the influence of repeated mining of the two working faces, this premise is put forward At the same time, to ensure the coal recovery rate, the chain arm saw developed by Tongmei group was used for mechanical roof cutting to achieve the effect of roof weakening. In order to study the stability of surrounding rock under the condition of repeated stress disturbance in two working faces, the distribution of stress and deformation of surrounding rock after roof cutting and no roof cutting was studied by means of numerical simulation and mechanical analysis. The results show that: the chain arm sawing roof pressure relief can effectively cut off the stress transfer between the basic roof, reduce the peak stress of roof and floor in the retained roadway, the stress distribution is uniform, and the peak stress concentration in small coal pillar is greatly reduced, which improves the stability of surrounding rock of retained roadway; at the same time, for the small coal pillar retained roadway, the solid coal side will still be affected by the advance stress and lateral stress, forming superimposed stress concentration area and small coal pillar In this paper, the corresponding improvement suggestions are put forward.