1. The State Key Laboratory for GeoMechanics and Deep Underground Engineering,China Univeristy of Mining & Technology,Xuzhou　 221116,China;2. Faculty of Resource and Safety Engineering,China University of Mining & Technology(Beijing),Beijing　 100083,China;3. Research Center of Top-coal Ca-ving Mining in Coal Mining Industry Beijing,Beijing　 100083,China

研制了工作面覆岩破断预测实验平台,对浅埋薄基岩条件顶板动载冲击效应进行了模拟;建立了顶板破断的弹性地基梁理论模型,计算出了基本顶破断时与煤壁的相对位置,得到了动载冲击的作用范围;建立顶板动载冲击的力学模型,结合岩石压缩曲线,应用功能原理得到了不同条件下的最大冲击载荷和支架伸缩量的解析表达式,得到了不发生压架事故的判别准则,验证了相似模拟实验结果。结果表明:基本顶多超前直接顶支撑边界破断,且冲击易发生液压支架上方完成;冲击载荷大小与直接顶厚度与裂隙发育程度、支架刚度和初撑力大小等因素有关,其值远大于工作面静载荷形成对液压支架的压力,动载冲击效应模拟实验验证了理论分析结果。

In this paper,an overlying strata breakage prediction experiment platform was developed and used to simu- late the dynamic load impact in shallow working face with thin-bedrock. A breaking model of roof strata based on the elastic foundation beam model was proposed to calculate the relative position between main roof’ s breaking and coal wall and analyze the sphere of dynamic loading. According to the mechanical model of roof movement and the stress- strain curve of uniaxial compression tests,the maximum dynamic load and support’s contraction were solved under dif- ferent situations by using the principle of work and power,the criterion of no supports crushing was obtained,and the physical analog simulation result was explained. The results show that the main roof always breaks ahead of its support- ing edge,so dynamic load impact often occurs on support. And the maximum load is related to the immediate roof’ s thickness,the crack’s development degree,the support’s stiffness and the initial support force and so on. Its value is far greater than the static load on the hydraulic support formed by overlying strata. The physical analogous simulation validated the mechanical analysis results.

国家重点基础研究发展计划(973)资助项目(2013CB227903)；国家自然科学基金项目资助项目(51574244,U1361209)；

Yang Shengli,Wang Jiachen,Yang Jinghu. Physical analog simulation analysis and its mechanical explanation on dynamic load impact[J]. Journal of China Coal Society,2017,42(2):335-343.