摘要
通过建立下保护层中残留孤岛煤柱的结构力学模型,应用力学原理分析了残留煤柱及被保护层煤体中的应力状态,得到煤柱诱发冲击地压具有2种机理:①在煤柱外围的强剪切区内岩层受剪断裂诱发冲击地压;②煤体本身破裂所致.这一过程在煤柱区附近表现为微震事件在煤柱区前方50 m开始"停滞"不前,应力出现分区性.研究了煤柱失稳破裂过程中微震事件能量统计曲线与失稳破裂过程的对应关系,得到了煤柱的失稳破裂是由微破裂到局部失稳、由渐变到突变的过程.现场采用深孔爆破和大孔径钻孔对煤柱进行卸压后,微震事件沿工作面倾向方向的分布呈均匀形态,且能量较小,证明了卸压效果十分明显.
The mechanisms of rock-bursting associated with remnant pillar were presented together with a mechanical modeling of the pillar failure, and an analysis of the stress conditions associated with the pillar and the nearby distressing coal seams. Two mechanisms were provide： ① Shear failure within shear zones induced in the proximity of the pillar; ② Failure of the pillar-itseff. The existence of these shear zones was demonstrated by clusters of events occurring well over 50 m ahead of the pillar and remaining there as the face advances. In addition, the process of the pillar failure from initial micro-fracturing to local failure and final collapse was studied by comparing the energy distribution curve against rock failure. After the release of pressure in both floor and roof by using deephole blasting and large-diameter drilling, events with lower energy occur. This is typically observed in de-stressed regions.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2009年第9期1169-1173,共5页
Journal of China Coal Society
基金
国家自然科学基金重点资助项目(40674017
50774012)
关键词
孤岛煤柱
冲击地压
微震监测
力学机理
remnant pillar
rock burst
microseismic monitoring
mechanical mechanism
