摘要
由冲击动力造成的巷道破坏是一种典型的煤岩动力灾害,严重威胁着矿井的安全生产。针对义马煤田千秋矿21141工作面运输巷频繁发生冲击破坏的问题,在分析典型巷道冲击破坏微震监测能量特征的基础上,开展了常规三轴压缩试验并结合理论分析、数值模拟等手段,研究了煤岩体发生冲击破坏时的能量特征。研究结果表明:巷道围岩冲击破坏发生前,微震监测最大能量波动幅度较小,但是每次巷道围岩冲击破坏事件的发生均伴随有微震监测能量的急剧增大;试件双向载荷比值(轴压/围压)对声发射能量特征有显著影响,加载速率相同时,围压越大,能量峰值越小;在一定条件下,采动应力、巷道扩修、巷内爆破等事件产生的扰动加载作用能够改变区域应力场中巷道双向载荷比值,使得塑性区形态特征由非蝶形转化为蝶形,或导致塑性区蝶叶出现瞬时扩展,并以震动、声响和煤岩碎块抛出的形式释放存储于围岩系统中的大量能量,从而诱发巷道围岩冲击破坏。在实际的工程实践中,可以采取降低采煤工作面推进速度、控制开采截深、调控巷道围岩区域应力场等措施,以减小煤岩体的加载速率,防止大能量事件的产生,避免巷道蝶形塑性区瞬时扩展过程中能量的突然释放。
Roadway failure caused by burst dynamic pressure is a typical coal-rock dynamic disaster,which seriously threatens the safe production of coal mine.In view of the frequent burst failure in the 21141 haulage roadway in Qianqiu coal mine of Yima mining area,the energy characteristics of coal and rock mass during burst failure were studied by means of theoretical analysis and numerical simulation.On the basis of analyzing the energy characteristics of micro-seismic monitoring of typical roadway burst failure,a conventional triaxial compression test was carried out.The results showed that the maximum energy fluctuation range of microseismic monitoring before surrounding rock burst failure was small,and every occurrence of burst failure event was coupled with sharp increase in energy.The ratio of bidirectional load of specimens(axial pressure/confining pressure)had a significant influence on the characteristics of acoustic emission energy.At the same loading rate,the higher the confining pressure was,the smaller the peak energy was.Under certain conditions,the influence of disturbance loading caused by events,such as mining stress,roadway repair,blasting and so on,the bidirectional load of roadway in regional stress field was obviously changed accordingly which it may cause the morphological characteristics of plastic zone change from non-butterfly shape to butterfly shape,or leaded to the instantaneous expansion of butterfly-shaped plastic zone,thus a plenty of energy which was gathered in the surrounding rock system would be suddenly released in the form of vibrations,sound,coal and rock mass flings and induced roadway surrounding rock burst failure.In practical engineering practice,it is suggested to reduce the advancing speed of coal face,control the cutting depth of coal face and adjust the stress field of surrounding rock of roadway,so as to reduce the loading rate of coal and rock mass,prevent the occurrence of large energy events and avoid the sudden release of energy during the instantaneous expansion of the butterfly shaped plastic zone of roadway.
作者
镐振
郭林峰
赵希栋
陈国祥
张国华
HAO Zhen;GUO Linfeng;ZHAO Xidong;CHEN Guoxiang;ZHANG Guohua(Safety Engineering College,Henan University of Engineering,Zhengzhou 451191,China;School of Energy & Mining Engineering,China University of Mining and Technology (Beijing),Beijing 100083,China;Safety Engineering College,North China Institute of Science and Technology,Langfang 065201,China;Qianqiu Coal Mine,Yima Coal Industry Co.,Ltd.,Henan Energy & Chemical Industry Group Co.,Ltd.,Yima 472300,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2020年第12期3995-4005,共11页
Journal of China Coal Society
基金
河南省高等学校重点科研资助项目(20A440002)
国家自然科学基金资助项目(51804117,51674243)。
关键词
回采巷道
冲击破坏
能量
塑性区
蝶形
mining roadway
burst failure
energy
plastic zone
butterfly shape
