摘要
为研究西部地区弱胶结地层煤层群开采过程中覆岩渗透性演化规律,以伊犁矿区伊新煤业开采地质条件为基础,通过构建弱胶结采动地层数值计算模型,分析了重复开采扰动下弱胶结煤系地层覆岩的应力分布特征、塑性破坏区发育及渗透性演化规律。结果表明:近距离上位煤层开采时,采动支承压力峰值的应力集中系数达到1.81,采空区覆岩最大拉应力值达到0.9MPa;上位煤层工作面推进距离达到300 m时,采空区上行破坏区和下行破坏区相互导通;重复开采扰动下,弱胶结地层采动覆岩的孔隙压力大幅下降,采动渗流场呈现采空区四周渗流速度大于采空区中部渗流速度、采空区煤壁侧的渗流速度大于两侧和切眼侧渗流速度,当上行和下行破坏区连通时渗流速度大幅增大;近距离下位煤层开采,当煤层间岩层破坏区初次贯通时,上下煤层间岩层形成中间渗流速度大、两边渗流速度小的扇形渗流场,随着工作面持续推进,最大渗流速度位于工作面前方。
In order to study the permeability evolution law of coal measure strata during multi-seam mining of weakly consolidated strata in western China,based on the double coal seam mining of Yixin Coal Industry in Ili Mining Area,Xinjiang,a numerical calculation model of weakly cemented strata is established,and the permeability evolution law of weakly cemented coal measure strata,the stress distribution characteristics of overburden and the development characteristics of plastic failure under the condition of repeated mining are analyzed.The results show that: the stress concentration coefficient of the peak value of abutment pressure reaches 1.81 during the process of mining near upper coal seam,and the maximum tensile stress of overburden in goaf reaches0.9 MPa;the upward and downward cracks in the goaf conduct when the advance distance of the working face reaches 300 m;after coal mining,the pore pressure of overburden decreases significantly,and the mining-induced overburden seepage field presents a distribution law of large seepage velocity around the goaf and small seepage velocity in the middle,and the seepage velocity of coal wall side of working face is greater than the seepage vector of cut hole side,the simulation shows that the seepage velocity increases greatly when the ascending and descending fractures are conduction;when the failure zone between coal seams is first penetrated through,the fan-shaped seepage field is formed between the upper and lower coal seams with high seepage velocity in the middle and low seepage velocity on both sides,and with the continuous advance of the working face,the maximum seepage velocity lies in the front of the working face.
作者
刘洪林
肖杰
甄文元
朱铖宇
陈志文
罗文杰
LIU Honglin;XIAO Jie;ZHEN Wenyuan;ZHU Chenyu;CHEN Zhiwen;LUO Wenjie(School of Geology and Mining Engineering,Xinjiang University,Urumqi 830046,China;Key Laboratory of Colleges and Universities in the Autonomous Region for Protective Mining of Mineral Resources and Ecological,Urumqi 830046,ChinaEnvironment,Xinjiang University;Mining Research Branch of China Coal Research Institute,Beijing 100013,China)
出处
《煤矿安全》
CAS
北大核心
2022年第12期218-225,共8页
Safety in Coal Mines
基金
国家自然科学基金资助项目(51964043,U1903216)
新疆维吾尔自治区自然科学基金资助项目(2022D02E22,2019D01C023)
国家级大学生创新训练计划资助项目(202210755007,202010755085)。
关键词
弱胶结
采动覆岩
渗透率演化
数值模拟
重复采动
weak cementation
mining-induced overburden
permeability evolution
numerical simulation
repeat mining
