顶板动载冲击效应的相似模拟及理论解析

发布时间：2019-01-23 13:21

【摘要】：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。
[Abstract]:An experimental platform for prediction of overburden failure in working face is developed, and the impact effect of dynamic load on the roof of shallow buried thin bedrock is simulated. The theoretical model of elastic foundation beam with roof breaking is established, the relative position of the basic roof breaking and the coal wall is calculated, and the action range of dynamic load impact is obtained. The mechanical model of roof dynamic load impact is established. Combining with rock compression curve, the analytical expressions of maximum impact load and support extension under different conditions are obtained by applying the function principle. The simulation results are verified. The results show that the edge of direct top support is broken at most, and the impact is easy to happen above the hydraulic support. The impact load is related to the thickness of the direct roof and the degree of fracture development, the stiffness of the support and the magnitude of the initial bracing force, and its value is much larger than the pressure on the hydraulic support formed by the static load of the working face. The results of theoretical analysis are verified by simulation experiments of dynamic impact effect.
【作者单位】：中国矿业大学深部岩土力学与地下工程国家重点实验室;中国矿业大学(北京)资源与安全工程学院;放顶煤开采煤炭行业工程研究中心;
【基金】：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)
【分类号】：TD324

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