关键词: 近距离煤层, 煤层开采, 矿压显现, 顶板结构

Abstract: In order to master the influence law of short distance upper coal seam goaf and residual coal pillar on ground pressure behavior of lower coal seam mining face, taking the geological conditions of 10# (lower) coal seam mining face after 9# (upper) coal seam mining in Shanxi as the engineering background, and uses the methods of theoretical analysis, numerical simulation and field measurement, the ground pressure behavior law, roof structure evolution characteristics and support resistance of the working face under the goaf and coal pillar are classified and studied. The results show that: 1) The dynamic load coefficient under the goaf is 19.35% higher than that under the coal pillar when the lower coal seam 1001 working face is pressed periodically. During the non pressure period, the support load under the coal pillar increases by 20.58% on average compared with that under the goaf; 2) When the upper coal seam is mined, the key layer 1 forms an articulated bearing structure. When the lower coal seam is mined under the goaf, the articulated structure loses stability and collapses, and the collapse zone develops upward until the key layer 2 forms an articulated structure to bear the load of the overlying strata; 3) The residual coal pillar in the upper coal seam has strong stability and bearing capacity, and the peak value of floor concentrated stress caused by coal pillar appears in the center line of coal pillar. When the lower coal seam is mined under the coal pillar, the key layer 2 forms a hinged structure to bear the load of the overlying strata; 4) The ground pressure control measures to increase the working resistance of the support are put forward. According to the on-site observation, the slope phenomenon has been improved, and the support can ensure the safe mining of the fully mechanized top coal caving face.