摘要
分析了矿震激发震动波能量的传播模式、衰减特征及动态应力降大小,并基于能量和刚度理论,分析了动静载组合作用下巷道煤体的冲击破坏机理。研究表明,矿震震动能量的传播衰减特征主要依赖于能量几何扩散、传播岩体介质的阻尼衰减,以及矿震震源的震动位移场和能量辐射特征的综合影响。矿震动载传播至采场或巷道围岩时,分别与煤岩系统的静态应力(能量)场进行能量标量和应力矢量叠加。矿震动载的能量叠加可使煤岩系统聚集的能量增加,而应力叠加使系统内煤体变形破坏做功所消耗的能量减小,从而使系统聚集和消耗的"差能"增加。系统可释放的"差能"越多,煤体失稳的可能性越大,当动静载组合作用下煤岩系统同时满足冲击矿压发生的能量和刚度条件时,煤层发生动态冲击破坏。
The seismic energy transmission modes and attenuation rules radiated by mining-induced tremor as well as the dynamic stress drop were theoretically analyzed.Using the energy and stiffness theory of rock burst,the mechanism of rock burst induced by residual dynamic load of mining-induced tremor in the surroundings rock were further revealed.The results show that the transmission and attenuation of seismic energy mainly depends on the comprehensive influence of seismic wave geometry spreading,coal and rock media damping effort,and failure mechanism of the source.When the tremor spreads to the surrounding rocks of roadways or longwall faces,the dynamic load superposes with the original static stress field（energy field） in forms of scalar superposition of energies and vector superposition of stresses.The superposition of energies makes the aggregated energy of the coal-rock system increased,while the superposition of stresses makes the energy consumed for working decreased in the process of deformation and failure of coal mass,thus making the energy difference between aggregated and consumed energies increased.The more the energy difference released in the system,the greater the possibility of the coal mass instability.When the energy and stiffness conditions of the system are satisfied simultaneously in the composite effort of dynamic and static load,the rock burst in coal seam is happened.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2010年第12期2006-2010,共5页
Journal of China Coal Society
基金
国家自然科学基金资助项目(50490273
50474068)
国家重点基础研究发展计划(973)资助项目(2005CB221504
2010CB226805)
国家"十一五"科技支撑计划项目(2006BAK04B02
2006BAK04B06)
2007年国家建设高水平大学公派研究生项目([2007]3020)
中央高校基本科研业务专项资金(2010QNA30)
关键词
矿震
围岩
震动效应
冲击矿压
震动波
应力降
能量耗散
mining-induced tremor
surrounding rock
seismic effect
rock burst
seismic wave
stress drop
energy dissipation
