冲击载荷作用下弹、塑性组合煤体动态损伤特性研究  

Dynamic damage characteristics of elastic and plastic combination coal under impact loading

作　　者：李峰[1] 张亚光[1] 方书昊 张良[1] 刘建荣[1] 

机构地区：[1]中国矿业大学(北京)资源与安全工程学院,北京100083

出　　处：《采矿与安全工程学报》2016年第6期1096-1102,1109,共8页Journal of Mining & Safety Engineering

基　　金：国家自然科学基金重点项目(U1261214)

摘　　要：以掘进巷道前方分布的弹、塑性组合煤体为研究对象,基于应力波的传播规律,研究冲击载荷作用下煤体中应力波的传播过程,加、卸载波相互作用下拉应力波的形成及作用机理。研究表明:弹、塑性组合煤体在冲击载荷作用前后,加、卸载波在波阻抗不同的分界面将发生反射与透射,形成多束卸载波;卸载波的作用能产生拉应力,易致使煤体发生破坏;冲击载荷作用下掘进工作面前方塑性煤体与弹性煤体的分界面附近煤体中易形成拉应力较大的区域,导致煤体发生急剧损伤、瓦斯解吸速度急剧增加、瓦斯压力急剧上升,从而导致煤与瓦斯突出事故的发生,是由内至外的发展过程;加、卸载应力波在孔洞周围的弹、塑性煤体传播过程中会发生多次反射与透射产生多束卸载波,卸载波之间相互作用产生的拉应力,可使煤与瓦斯突出过程中呈现层裂现象。Based on stress wave propagation, the paper researched stress wave propagation process in coal under impact loading and the formation and acting mechanisms of tensile stress waves under the interaction of the loading and unloading stress waves with the elastic and plastic combination coal in front of the tunneling faces as study objects. The results have shown that loading and unloading stress waves would be reflected and transmitted at the interface with different impedances under impact loading in elastic and plastic combination coal, formatting multi-beam unloading waves; the unloading stress waves would produce tensile stress waves, leading to tensile failure in coal; it is liable to form large tensile stress area near the interface of plastic and elastic coal in front of the tunneling faces under impact loading, leading to sharp injuries in coal, the gas desorption speed increasing dramatically, and gas pressure rising sharply, further leading to the coal and gas outburst accident, which is a developing process from inner to outer; loading and unloading stress waves would be frequently reflected and transmitted in the process of transmission in elastic-plastic coal around hole, and multi-beam unloading waves would be formed; the tensile stress produced under the interaction of these unloading waves will lead to the phenomenon of spallation in the process of coal and gas outburst.

关 键 词：冲击载荷 弹、塑性组合煤体 卸载波 拉应力 动态损伤 

分 类 号：TD713[矿业工程—矿井通风与安全]