瓦斯突出作用下煤岩体中冲击波传播规律的研究

Study on propagation laws of shock wave in coal-rock mass under the effect of gas outburst

通过40余次的煤与瓦斯突出模拟实验,揭示了冲击波的形成原因,据此建立起冲击波在煤岩体中的一维传播模型。根据应力波理论,分析了其主要的传播规律:①冲击波在煤体界面上传播时,折射进入煤体的冲击波应力值约为入射冲击波的两倍;②冲击波在单个层状煤体中传播时,冲击波会在单个层状煤体两端自由界面上出现反射,产生巨大拉应力,拉应力又将其撕裂成若干个更薄的层状体;③冲击波传播到构造煤和岩石(硬煤)组合介质中分界面上时,在交界面处产生强烈的透射和反射,反射波反向加载,煤体受到强烈压缩作用,当其超过软煤强度时,软煤被压裂破坏。从整个突出过程来说,拉应力对煤体的破坏起到主要作用。

The formation reasons of shock wave were revealed through over forty simulation experiments for coal and gas outburst.On this basis,a one-dimensional propagation model of shock wave in coal-rock mass was developed.According to the stress wave theory,main propagation laws of shock wave were analyzed as follows：① When a shock wave propagation on the coal interface,the stress value of the shock wave reflected into the coal-rock mass is twice that of the incident shock wave;② When a shock wave propagation in a single layered coal,it will be reflected on the free interface at both ends of the single layered coal,and tremendous tensile stress will be generated,which will tear the single layered coal into several thinner laminas;③ When a shock wave propagation to the interface in the assembled medium of tectonic coal and rock（hard coal）,strong assembled and reflection will be created at the interface with reverse loading of the reflected wave and strong compressing in the coal.When the strength exceeds that of soft coal,the soft coal will be fractured and damaged.In terms of the whole outburst process,tensile stress plays a major role in damaging the coal.