顶板断裂瞬间煤体稳定性的动力学分析及数值模拟  

Dynamics analysis and numerical simulation on coal stability at the moment of roof fracture

作　　者：祝捷[1,2] 张敏[1] 唐俊[1] 王曌华[1] 谈晓钟 

机构地区：[1]中国矿业大学(北京)力学与建筑工程学院,北京100083 [2]中国矿业大学(北京)煤炭资源与安全开采国家重点实验室,北京100083

出　　处：《煤炭学报》2014年第2期253-257,共5页Journal of China Coal Society

基　　金：国家重点基础研究发展计划(973)资助项目(2010CB226801);中国矿业大学煤炭资源与安全开采国家重点实验室开放基金资助项目(SKLCRSM10KFB09);高等学校博士学科点专项科研基金资助项目(20120023120011)

摘　　要：为了研究顶板突然性断裂诱发煤层失稳的致灾条件,本文采用动力学方法分析了顶板断裂瞬间煤岩系统的受力状态和力学响应。首先推导了顶板断裂时惯性力、惯性力矩的计算公式,进而得到顶板断裂瞬时转动加速度与惯性力、惯性力矩的关系,利用数值模拟计算了顶板断裂前后以及不同转动角加速度条件下的煤岩体应力、变形和两帮位移。计算结果显示:当顶板断裂瞬时转动角加速度较小,即顶板断裂释放能量较小时,工作面煤壁两帮移近量随顶板瞬时转动角加速度的增大而增大;当顶板断裂瞬间转动加速度达到某临界值时,煤岩系统出现失稳分支点,具体体现为工作面处煤体的应力基本不变,煤壁顶部竖向下沉激增,煤岩系统的平衡须依靠煤壁回缩方可维持。因此顶板断裂可以诱发煤岩体系统的失稳,但并非失稳的充分条件。The stress state and mechanical responses of coal and rock system at the moment of roof fracture were analyzed to investigate the disaster mechanism of coalburst due to roof fracture by means of the dynamic methods. And the inertial force and moment were deduced. Based on the relationship of the inertial force, moment and roof rotational acceleration, the stress, deformation and displacement of coal-rock mass before and after fracture, including different inertial angular acceleration conditions were simulated. The numerical results indicate that when roof rotational acceleration and its release energy is low, coal wall by the side of working face moves to roadway and its shift increases with roof rotational acceleration increasing. Once the inertial angular acceleration reaches a critical value, the bifurcation instability point occurs. The coal-rock system keeps stable only when coal wall retracts. Meanwhile the top of coal wall sink sharply though the stress is almost invariant. Therefore roof can course the instability of coal-rock system, but not a suf- ficient condition for coalburst.

关 键 词：煤体稳定性 顶板断裂 动力学分析 分岔失稳 

分 类 号：TD315[矿业工程—矿井建设]