采动煤岩不同破裂模式下的能量辐射与应力降特征  

Characteristics of Energy Radiation and Stress Drop in Different Failure Modes of Mining-Induced Coal-Rock Mass

作　　者：曹安业[1] 窦林名[1] 江衡 吕长国[1] 郭晓强[1] 王毅[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 [2]重庆市设计院,重庆400015

出　　处：《采矿与安全工程学报》2011年第3期350-355,共6页Journal of Mining & Safety Engineering

基　　金：国家自然科学基金项目(50490273,50474068);国家重点基础研究发展计划(973)项目(2010CB226805);中央高校基本科研业务专项资金项目(2010QNA30);煤炭资源与安全开采国家重点实验室自主研究项目(SKLCRSM10X05);江苏高校优势学科建设工程项目

摘　　要：理论比较分析煤岩在剪切、拉伸等破裂模式下的应力降、应变能释放及震动能量辐射特征,揭示采动煤岩不同破裂模式下的冲击危险差异.研究表明,煤岩破裂失稳释放的应变能随其破裂尺度的增大而增大,且在相同破裂尺度下,煤岩剪切破裂释放的能量和产生的应力降远大于在拉伸破裂下的能量释放和应力降大小.在能量释放相同时,震源破裂尺度随其单轴抗压强度的增大而减小.同时,不同采动煤岩矿震因震源矩张量成分的差异,其震动位移场及能量辐射方式也不尽相同.煤岩拉伸破裂的微震波形往往P波初动清晰,S,P波的能量比(振幅比)较小,而剪切破断则表现出P波初动微弱,S,P波的能量比(或振幅比)较大的微震特征.In this paper,we theoretically analyze characteristics of stress drop,the strain energy release,and seismic radiation pattern associated with the rock tensile fracture and shear failure to reveal the corresponding burst risk ranks of coal-rock mass in various failure modes.The results show that the stress required to fail the rock and the associated energy released by rock failure are different,mainly depending on the fracture mode within the rock mass.In case of the same physical and mechanical properties,the energy released increases with the increase of fracture radius.Given the same fracture radius,the stress drop and energy released associated with shear failure are significantly greater than that of tensile fracture.In addition,in case of the same energy released,the fracture radius decreases with the increase of uniaxial compressive strength of the rock mass.Meanwhile,the seismic displacements and energy radiation patterns of different mining-induced tremors vary with different components of the moment tensors.The seismic waveforms of tensile fractures are always characterized by clear P-wave arrivals and the ratio of S-to P-wave energy or amplitude is relatively small,while the shear failures always present weak P-wave arrivals and the ratio of S-to P-wave energy or amplitude is much greater.

关 键 词：应力降 能量释放 剪切破裂 拉伸破裂 破裂半径 震源矩张量 

分 类 号：TD324[矿业工程—矿井建设]