动载荷作用下构造煤体动力响应特性研究  

Dynamic response characteristics of tectonic coal under dynamic loading

作　　者：李峰[1] 张亚光[1] 刘建荣[1] 刘丹龙[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：《岩土力学》2015年第9期2523-2531,共9页Rock and Soil Mechanics

基　　金：国家自然科学基金重点资助项目(No.U1261214)

摘　　要：以掘进巷道前方分布的塑性煤体、弹性煤体、构造煤体与原始煤体的组合为研究对象,基于应力波的传播与作用规律,对动载荷作用下煤体中应力波的传播过程及其动态损伤机制进行研究,揭示了构造煤体的动力响应特性。研究结果表明:动载荷作用下,主要的拉应力产生区域集中分布在波阻抗发生变化的区域,最大拉应力分布在弹性煤体和塑性煤体的分界面及其附近区域;煤体中拉应力产生与卸载波的作用紧密相关,同时在地应力的综合作用下,煤体易发生拉剪破坏;动载荷作用过程中,构造煤体承载冲击的能力较弱;但正是由于构造煤体的存在,在卸载应力波作用过程中,煤体中会产生较强的拉应力,极易导致某些区域的煤体发生急剧损伤;加、卸载应力波在传播过程中会发生多次反射与透射并产生多束卸载波,在卸载波作用下,煤体周围易形成拉应力区,可导致煤与瓦斯突出过程中煤体破坏,呈现层裂现象。研究结论对于矿井煤岩动力灾害的防治具有重要意义。Based on the theory of stress wave propagation and interaction, the propagation process and damage mechanism of coal are studied when stress wave propagates through the coal comprising plastic coal, elastic coal, tectonic coal and initial coal in front of the tunneling. Furthermore, the dynamic response of tectonic coal is revealed. The results show that the main tensile stresses distribute centrally in coal regions, where the wave impedance changes under dynamic loading. It is also found that the maximum tensile stress is around the interface of plastic and elastic coal. In addition, the occurrence of tensile stress is closely related to the unloading wave, which result in the tensile-shear failure of coal in combination with the effect of in-situ stress. It is clearly shown that the carrying capability of tectonic coal to dynamic loading is weak. Due to the existence of tectonic coal, the strong tensile stress is generated in elastic coal under unloading stress waves, which easily leads to heavy damage in some parts of elastic coal. Stress waves are frequently reflected and transmitted in loading and unloading processes and consequently multi-beam unloading waves are produced. Under the effect of such unloading waves, the formation of tensile stress area in the vicinity of coal bed results in the spalling phenomenon at the moment of coal and gas outbursts. This study has theoretical significance as it contribute to controlling and preventing the dynamic disasters of coal and rock in mine.

关 键 词：动载荷 构造煤体 卸载波 动态损伤机制 动力响应 

分 类 号：TU435[建筑科学—岩土工程]