上覆遗留区段煤柱对下伏煤层开采扰动影响研究  

Study on disturbing influence of overlying remaining coal pillars on underlying coal seam mining

作　　者：李春元 王泓博 石瑶玉 LI Chunyuan;WANG Hongbo;SHI Yaoyu(School of Mechanics and civil Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China;Schoo of Energy and Mining Engineering,China University of Mining and Technology Bejing,Bejing 100083,China)

机构地区：[1]中国矿业大学(北京)力学与建筑工程学院,北京100083 [2]中国矿业大学(北京)能源与矿业学院,北京100083

出　　处：《煤炭科学技术》2020年第3期232-239,共8页Coal Science and Technology

基　　金：国家自然科学基金资助项目(51904303);中央高校基本科研业务费专项资金项目(2011YZ05)。

摘　　要：上覆遗留区段煤柱导致底板应力环境改变,而下伏采场在开采扰动和遗留区段煤柱底板高应力双重作用下极易出现剧烈矿压问题。根据遗留区段煤柱对底板应力的扰动传播规律,研究了下伏煤层开采前后上覆遗留区段煤柱对底板应力的扰动演化机制,计算分析了遗留煤柱区域下伏煤层开采的扰动宽度范围;应用FLAC3D数值软件模拟了上覆遗留区段煤柱影响下下伏煤层开采的扰动破坏特征;现场实测验证分析了遗留区段煤柱对下伏煤层巷道布置及采场来压的影响。结果表明:下伏煤层开采前遗留区段煤柱对下伏煤层的扰动范围与煤柱宽度和层间距呈正相关关系,但层间距对扰动范围的影响更为显著;下伏煤层开采后,在采动及遗留区段煤柱底板高应力叠加作用下,下伏采场推进方向由煤壁向采场前方深部,扰动宽度较下伏煤层开采前呈增加—减小—稳定趋势,并在超前支承压力峰值处宽度达到最大;煤柱宽度20 m时,下伏煤层开采后的最大扰动宽度可由开采前的30 m增加至36 m,增加20%,扰动角由32°增高至45°,增高40.6%,超前支承压力峰值较开采前也增加了14.8 MPa;且现场回采时,遗留煤柱区域下伏采场来压步距均值28.3 m,较采空区下来压步距均值20.5 m增加约38%,动载系数增高约7.1%,应加强遗留煤柱扰动范围内的顶板维护,确保下伏采场安全开采。Disturbance of coal pillars in the overlying remaining section results in a change in the stress environment of the floor,while underlying working face are prone to severe mine pressure problems under the dual effects of mining disturbances and high floor stresses of the coal pillar.According to the disturbance propagation law of the coal pillar on the floor stress in the remaining section,the disturbance mechanism of coal pillar on the stresses at floor area before and after overlying coal seam was studied,and the disturbance width of remnant coal pillar area during underlying coal seam mining was calculated and analyzed.The FLAC3 Dnumerical software was used to simulate the disturbance and damage characteristics of underlying coal seam mining under the influence of overlying remnant coal pillar.Then the influence of remnant pillar on roadway layout and the weighting of working face in underlying coal seam were analyzed and verified by field measurement and observation.The results show that the disturbance range of remnant pillar on underlying coal seam before underlying coal seam mining has a positive correlation with the width of coal pillar and the interval between the coal seams,but the influence of the interval between the coal seams on the disturbance range is more significant.After the mining of underlying coal seam,under the superimposition high stress of the coal pillar floor in the mining and remaining sections,along the advancing direction of underlying coal seam,the disturbance width is increased-decreased-stabilized compared with that before the mining of underlying coal seam,and the width at the peak of the advanced support pressure reaches the maximum.When the remnant coal pillar width is 20 m,the maximum disturbance width after underlying coal seam mining can be increased from 30 m to 36 m,an increase of 20%,and the disturbance angle is increased from32°to 45°,an increase of 40.6%;and the peak value of front abutment pressure is also increased by 14.8 MPa compared with that before underlying co

关 键 词：遗留区段煤柱 下伏煤层 应力扰动 超前支承压力 近距离煤层群 

分 类 号：TD323[矿业工程—矿井建设]