基于应力释放率与微震监测的高强度开采工作面推进速度效应分析  

Mining rate effect of high-intensity working face based on stress release rate and microseismic monitoring

作　　者：李杨 杨天鸿[3] 郝耐[2] 宋卫东[1] 付建新[1] 于玲[1] LI Yang;YANG Tianhong;HAO Nai;SONG Weidong;FU Jianxin;YU Ling(Key Laboratory of Ministry of Education for Efficient Mining and Safety of Metal Mines,University of Science and Technology Beijing,Beijing 100083,China;State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China;School of Resources&Civil Engineering,Northeastern University,Shenyang,Liaoning 110819,China)

机构地区：[1]北京科技大学金属矿山高效开采与安全教育部重点实验室,北京100083 [2]中国矿业大学(北京)深部岩土力学与地下工程国家重点实验室,北京100083 [3]东北大学资源与土木工程学院,辽宁沈阳110819

出　　处：《采矿与安全工程学报》2021年第2期295-303,共9页Journal of Mining & Safety Engineering

基　　金：中央高校基本科研业务费专项资金项目(FRF-TP-18-021A1);国家重点研发计划项目(2017YFC0602901);中国矿业大学(北京)深部岩土力学与地下工程国家重点实验室开放基金项目(SKLGDUEK2022)。

摘　　要：西部大规模高强度开采已经带来了严重的地质灾害和环境损伤问题,而工作面的推进速度是高强度开采的重要特征之一,故开展在高强度开采条件下推进速度对关键层破坏及失稳机制的影响规律研究具有重要的指导意义。推进速度的影响实际上是一个时间效应问题,本文针对以往研究成果在计算推进速度影响规律时所忽略的时间效应问题,利用岩土有限元分析软件Midas/GTS的LDF功能,开展基于应力释放率的推进速度效应分析。并依托高强度开采矿山现场,通过微震事件的定位结果,分析验证推进速度的影响规律。结果表明,当工作面推进速度较慢时,应力调整范围较大,形成“马鞍形”的应力调整区;而当工作面以较快速度推进时,应力调整范围较小,且形成“子弹形”应力调整区。随着工作面推进速度的增加,每天产生的微震事件分布范围(即开采引起的破坏区)明显减小,工作面后方的微震事件分布范围明显增加,微震事件在煤层顶板的发展高度也变低,从而减小了对岩层的破坏。可以看出工作面推进速度增加的实质是,围岩变形破坏特征时间效应的体现,围岩岩体的变形时间缩短,影响了围岩应力调整的完整程度,形成了不同的围岩应力调整范围。Serious geological disasters and environmental damages have been caused by high-intensity mining in Western China.As mining rate of working face is one of the important characteristics of high-intensity mining,it is of great guiding significance to study the effect of mining rate on the failure and in stability mechanism of key strata under high-intensity mining.The effect of mining rate is actually an issue of time effect.In view of the problem of time effect neglected in previous research results about calculating the effect law of mining rate.the analysis of mining rate effect based on stress release rate was carried out with the LDF function of the geotechnical finite element analysis software Midas/GTS.Based in the coalmine with high-intensity mining,the effect law of mining rate was analyzed and verified through localization results of microseismic events.The results have shown that when mining rate of working face is slower,the stress adjustment range is larger and forms a“saddle-shaped”stress adjustment area;when the working face is at a faster mining rate,the stress adjustment range is small,and a“bullet-shaped”stress adjustment zone is formed.With the increase of mining rate of working face,the distribution range of microseismic events(i.e.,the damage area caused by mining)produced every day decreases obviously,the distribution range of microseismic events behind the working face increases,and the development height of microseismic events in the coal seam roof decreases,which reduces the damage to the rock strata.It can be seen that the essence of the increase of mining rate of working face is the time effect of the surrounding rock deformation and failure characteristics.The deformation time of surrounding rock mass is shortened,which affects the complete degree of stress adjustment of surrounding rock mass and forms different stress adjustment ranges.

关 键 词：煤矿 推进速度 应力释放 微震 数值模拟 

分 类 号：TD82[矿业工程—煤矿开采]