煤样变形破坏峰值前后电磁辐射特征研究  

STUDY ON ELECTROMAGNETIC EMISSION CHARACTERISTIC FOR COAL SAMPLE DEFORMATION AND FAILURE DURING PRE-AND POST-PEAKING PHASES

作　　者：窦林名[1] 王云海[2] 何学秋[1] 王恩元[1] 

机构地区：[1]中国矿业大学能源与安全工程学院 [2]中国安全生产科学研究院,北京100029

出　　处：《岩石力学与工程学报》2007年第5期908-914,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(50490273;50474068;50074030);国家重点基础研究发展规划(973)项目(2005CB221504);"十一五"国家科技支撑计划项目(2006BAK04B02);教育部博士点基金资助项目(20030290017)

摘　　要：对不同矿区7种类型的硬煤、软煤、混凝土等进行实内试验研究。试验结果表明,电磁辐射水平与煤岩所受的应力水平关系密切,不同煤岩破坏峰前阶段的电磁辐射随应力的增加而起伏增强,峰前阶段的电磁辐射在应力水平为80%～95%时最强;峰后阶段的电磁辐射在峰值强度后随着应力的降低呈上升趋势,峰后阶段的应力水平为60%左右时,电磁辐射达到最大值,之后随着应力的下降,电磁辐射逐渐下降。冲击倾向的电磁辐射指数是指煤岩变形破坏峰后电磁辐射指标与峰前电磁辐射指标的比值,可分为冲击倾向的电磁能量指数和电磁脉冲指数。电磁能量指数和电磁脉冲指数与现有的冲击倾向指标有很好的线性关系,即电磁辐射能量指数和脉冲指数越大,煤岩的冲击倾向就越强。冲击倾向的电磁辐射指数可用来评价煤岩的冲击倾向,并以此确定冲击倾向的电磁能量指数和电磁脉冲指数判断煤岩冲击倾向性的分级指标值。因此,冲击倾向的电磁辐射指数是电磁辐射预测煤岩冲击倾向性及冲击危险程度的重要指标。The phenomenon of electromagnetic emission（EME） is caused during the deformation and failure processes of rock and coal. The experiments for seven types of rocks and coals such as hard coal, soft coal, concrete and so on collected from different collieries have been studied in the laboratories. The experimental results show that the EME strength is closely related to the rock and coal stress state. It usually increases with the stress increasing during the pre-peaking phase. The EME strength becomes most powerful when the stress level is 85% - 95% during the pre-peaking phase. However, the EME strength rises firstly and then falls with the stress decreasing gradually during the post-peaking phase. During the post-peaking phase, the EME strength comes to the maximum value when the stress level is about 60% during the post-peaking phase, then falls with the stress deceasing. The EME index of rock burst tendency can be defined as the ratio of EME strength in post-peaking phase and that in the pre-peaking phase. It includes two indexes, namely, EME energy index and EME pulse index of rock burst tendency. Both the EME indexes have closely linear relation with the index of rock burst tendency used at present, i.e. the higher both the EME indexes are, the more the liability of rock burst is. It can be used as an EME index to evaluate the liability of coal and rock burst. The classifications of the two indexes for evaluating the liability of rock burst have been established based on the results of experiments. The EME index becomes an important parameter for the EME method to forecast the rock and coal burst tendency and danger. The research results lay a good foundation for rock and coal burst prevention.

关 键 词：岩石力学 电磁辐射 峰值前后 冲击倾向性 冲击倾向电磁辐射指数 

分 类 号：TU45[建筑科学—岩土工程]