加载速率影响的煤体破裂过程声-电荷试验研究  

Experimental study on acoustic emission and charge signals during coal failure process at different loading rates

作　　者：肖晓春[1,2] 丁鑫 赵鑫[1] 潘一山[3] 王爱文[1] 王磊[1] 

机构地区：[1]辽宁工程技术大学力学与工程学院,辽宁阜新123000 [2]重庆大学煤矿灾害动力学与控制国家重点试验室,重庆400030 [3]辽宁大学物理学院,辽宁沈阳110136

出　　处：《岩土力学》2017年第12期3419-3426,共8页Rock and Soil Mechanics

基　　金：国家自然科学基金面上项目(No.51374123,No.51774164);国家自然科学基金青年项目(No.51504029,No.51504122);煤矿灾害动力学与控制国家重点试验室自主研究资助项目(No.2011DA105287-FW 201605)~~

摘　　要：为建立加载速率影响下煤体不同失稳形式的声发射-电荷判据,以阜新五龙矿某工作面为研究对象,采用物理试验研究方法,开展了不同加载速率下煤体破裂过程声-电荷监测试验,深入研究了加载速率影响的煤体力学性质、破裂规律和煤体破裂过程能量耗散与声发射-电荷信号的对应关系。研究结果表明:加载速率越高,应力调整越提前,煤样单轴抗压强度增加,累积变形能耗散加剧,煤体失稳形式由静载失稳过渡到类动载扰动失稳,煤体失稳破坏的动力特征明显,压缩型冲击地压动力灾害发生几率增大;不同加载速率下煤岩破裂过程产生的声-电荷信号变化与煤岩受载的应力突变具有较好的一致性;对所用煤样的声发射-电荷信号进行量化分析,初步提出了判定煤体失稳形式的声-电荷复合判定依据,在不同矿区、不同工作面上,可依据监测获得的声-电荷现场数据辅以采动应力场的变化情况,对采动过速诱发的煤体压缩型冲击地压的发生几率进行预测和预警。This study aims to establish a criterion of acoustic emission（AE） and charge signal for different failure forms of coal at various loading rates. Physical experiments were conducted on coal from a work-face of Wulong mine, and the AE and charge signals were monitored during the failure process of coal at different loading rates. Then we thoroughly investigated the relationships among AE-charge signals and mechanical properties, cracking, energy release at various loading rates. The results showed that with higher rates and earlier stress adjustment, uniaxial compressive strength improved, the release of accumulated deformation energy aggravated, failure modes changed from static load-induced instability to similarity-dynamic-load induced instability, more dynamic characteristics were present, and the risk of compressible rock burst of coal increased. At different loading rates, the AE-charge signal variations were consistent with stress mutation, which were further analysed quantitatively. Hence, based on the obtained AE-charge signals, we proposed a criterion for different coal failure modes. In different mines and work-faces, we could forecast or make an early warning to the risk of compressible rock-burst induced by mining, according to the monitored AE-charge signals in combination with variations of the mining pressure field.

关 键 词：加载速率 煤体失稳形式 能量耗散 声-电荷复合判据 煤体压缩型冲击地压 

分 类 号：TU443[建筑科学—岩土工程]