本煤层超前卸压瓦斯抽采的固-气耦合试验  

Experimental study of coupling between solid and gas during drainage by advance pressure relief in mining-coal seam

作　　者：秦伟[1] 许家林[1] 彭小亚[1] 

机构地区：[1]中国矿业大学矿业工程学院煤炭资源与安全开采国家重点实验室,江苏徐州221116

出　　处：《中国矿业大学学报》2012年第6期900-905,共6页Journal of China University of Mining & Technology

基　　金：国家自然科学基金重点项目(50834005);煤炭资源与安全开采国家重点实验室自主研究课题(SKLCRSM08X05);江苏高校优势学科建设工程项目(SZBF2011-6-B35)

摘　　要：对不同工作面推进速度条件下的超前支承压力演化规律及瓦斯抽采量的变化规律进行了对比分析,对不同轴压卸载起始点、不同围压卸载速度情况下的煤岩固-气耦合规律进行了试验研究.结果表明:轴压、围压同时卸载过程中,煤样经历了应变回弹、应变增加及应变软化3个阶段,轴压卸载起始点越小、围压卸载速度越慢,应变回弹过程越明显.反之,煤样越快进入应变增加和应变软化阶段.固定围压、加载轴压过程中,煤岩渗透率逐渐降低,瓦斯流量变小.轴压、围压同时卸载过程中,煤岩渗透率由缓慢增大到快速增大.当轴压、围压卸载到一定程度后,煤岩渗透率发生突跳.轴压卸载起始点越高、围压卸载速度越快,煤岩渗透率发生突跳时的轴压卸载量越小.The relationship between lead abutment pressure and gas drainage quantity for differ- ent mining speeds was analysed. Solid-gas coupling during pressure unloading was experimen- tally examined for different unloading speeds and different unloading initial axial pressures. There are three stages observed in coal： A strain rebound stage~ an increasing strain stage~ and, a strain softening stage. Strain rebound is more obvious for lower initial pressures and slower unloading speeds of confining pressure. The increasing strain and strain softening stages are entered quickly with high initial pressures and rapid unloading rate of confining pressure. Axial loading for a fixed confining pressure caused a decrease in coal permeability and a de- crease in gas flow. Simultaneous decrease in confining and axial load pressures caused the per- meability to increase slowly at first but more rapidly later. At some point the permeability fluc- tuates abruptly as the confining pressure and axial load are removed. This fluctuation moves to lower unloading volume of axial pressure for higher initial axial pressure and more rapid unloa- ding of confining pressure.

关 键 词：瓦斯抽采 固-气耦合规律 煤体变形 渗透率 

分 类 号：TD712[矿业工程—矿井通风与安全]