坚硬顶板孤岛工作面冲击地压机理及前兆判别  

Precursor discrimination and mechanism of rock burst in the island workface with hard roof

作　　者：张宏伟[1] 曹煜 朱峰[1] 邵凌峰[1] ZHANG Hongwei;CAO Yu;ZHU Feng;SHAO Lingfeng(College of Mining Engineering,Liaoning Technical University,Fuxin 123000,China)

机构地区：[1]辽宁工程技术大学矿业学院,辽宁阜新123000

出　　处：《煤田地质与勘探》2018年第2期118-123,共6页Coal Geology & Exploration

基　　金：国家自然科学基金项目(51274117)~~

摘　　要：以忻州窑矿8939工作面为工程背景,运用弹性板理论分析坚硬顶板破断期间释放的弹性能量值,并利用FLAC3D数值模拟划分工作面回采期间的高应力区域,同时根据分形理论分析微震事件的时间分布、空间分布与冲击地压的内部关联。研究结果表明:坚硬顶板断裂前,悬露顶板由于旋转下沉不断对工作面前方煤体缓慢加载,由于过程缓慢,应力与能量不断向煤岩体深部转移,不易发生冲击地压。当顶板断裂时,会瞬间释放大量的弯曲应变能,对工作面周围煤体产生强大的脉冲作用,若脉冲能量超过冲击地压的临界值,则发生冲击地压的可能性较大。且冲击地压发生之前,煤岩体处于非稳定状态,会与外界积极交换能量,此时微震事件处于活跃期,当微震能量超过一定数值或微震事件的分维值低于某临界值时,易发生冲击地压。Taking 8939 workface in Xinzhouyao coal mine as the research engineering background,elastic plate theory is used to analyze the elastic energy released during the breaking of hard roof,and using FLAC3D numerical simulation software to divide the high stress area of panel,according to the fractal theory the internal relation of time distribution and spatial distribution of microseismic event and rock burst was analyzed.The research results show that before the hard roof was broken,the coal body in front of the panel had been slow ly loaded by exposed suspending roof because of rotation and subsidence.Because the process was slow,the stress and energy were transferred to the deep coal and rock mass.Therefore,the rock burst is not easy to occur.When the roof fractures,great amount of bending strain energy releases instantly,inducing strong pulse effect to the coal body around a working face.If the pulse energy is higher than the critical value of rock burst,then rock burst is more likely to occur.And before the occurrence of rock burst,coal-rock mass is in unsteady state,w ill actively exchange energy with the outside world,at this moment the microseismic events are in the active phase.When microseismic energy exceeds a certain value or the fractal dimension of microseismic events is lower than a critical value,rock burst is easy to occur.

关 键 词：冲击地压 坚硬顶板 孤岛工作面 弹性薄板理论 应力能量 微震监测 

分 类 号：TD324[矿业工程—矿井建设]