端帮压煤井工开采覆岩运动规律及控制研究

发布时间：2018-06-19 06:34

本文选题：井工开采 + 端帮压煤　；参考：《中国矿业大学》2017年博士论文

【摘要】：露天矿开采必然会遗留下大量无法采出的端帮压煤,不仅浪费了许多煤炭资源,而且造成煤自燃、坡体失稳等安全问题,井工开采露天端帮压煤是解决上述问题的有效方法。坡体内井工开采矿压显现不同于传统井工开采,同时井工开采扰动有可能引发坡体的滑坡失稳,因此研究端帮压煤井工开采覆岩运动及控制具有重要的理论意义及工程价值。本论文综合采用理论分析、物理模拟、数值模拟、现场监测等手段,就端帮压煤井工开采覆岩结构形态及力学行为、覆岩运动诱发坡体损伤演化机制、采动坡体稳定性及其评价方法、覆岩运动及采动坡体变形控制技术进行了系统研究,取得了以下创新性成果:(1)建立了端帮压煤井工开采工作面覆岩的“砌体梁”力学模型,分析得到了“砌体梁”结构内断裂岩块的几何运动、受力及其稳定性特征。将基本顶视作弹性板结构,得出了基本顶的变形估算式及破断行为。同时建立了井工开采工作面覆岩运动引起坡体失稳分析的“砌体梁-板-滑面”结构模型,提出了该模型中采动坡体稳定性分析的改进型Sarma法,给出了安全系数的求解算法。(2)采用相似模拟试验方法揭示了端帮压煤井工开采覆岩与采动坡体联动破坏过程,得到了“砌体梁-板-滑面”结构的动态演化规律,揭示了采动坡体台阶“L”形和弧形断裂演化机理,得出了采动坡体地表以横向裂隙、纵向裂隙和台阶滑移为主的破坏方式,提出了采动坡体的“横四区”破坏模式。(3)构建了井工开采扰动下坡体稳定性分析的强度折减数值计算模型,分析了采动坡体变形分布规律,通过塑性剪应变率分布和变形分布变化追踪了临界滑面位置与形状演化规律,得出了工作面推进对采动坡体安全系数的影响,为合理确定井工开采工作面停采线位置提供了依据。(4)揭示了调整采动坡体上覆荷载和控制软弱岩层滑移对覆岩运动和采动坡体变形的控制机理,提出了端帮压煤井工开采中针对采动坡体不同分区的回填压脚、削坡减重和布设抗滑桩控制技术,并在平朔矿区成功应用。该论文有图106幅,表13个,参考文献203篇。
[Abstract]:Open-pit mining is bound to leave a large number of unrecoverable end coal, which not only waste a lot of coal resources, but also lead to coal spontaneous combustion, slope instability and other safety problems. The open-pit side coal mining is an effective method to solve the above problems. The rock pressure behavior of wellbore mining in slope is different from that of traditional well mining, and the disturbance of well mining may lead to landslide instability of slope body. Therefore, it is of great theoretical significance and engineering value to study the overburden movement and control of longwall coal mining. In this paper, by means of theoretical analysis, physical simulation, numerical simulation, field monitoring and so on, the mechanism of slope damage evolution induced by overburden movement is discussed in terms of overburden structure and mechanical behavior. The stability of mining slope body and its evaluation method, overburden movement and deformation control technology of mining slope body are studied systematically. The following innovative achievements are obtained: 1) the "masonry beam" mechanical model of overburden rock in longwall caving coal mining face is established. The geometric movement, stress and stability of fractured rock block in masonry beam structure are analyzed. The basic roof is regarded as an elastic plate structure, and the deformation estimation and fracture behavior of the basic roof are obtained. At the same time, the structural model of "masonry beam-slab-sliding surface" structure for slope instability analysis caused by overlying rock movement in mining face is established, and an improved Sarma method for stability analysis of mining slope body is put forward in this model. The calculation algorithm of safety factor is given. (2) the similar simulation test method is used to reveal the process of joint failure between mining overburden and mining slope, and the dynamic evolution law of "masonry beam-plank-sliding surface" structure is obtained. The evolution mechanism of bench "L" and arc faults of mining slope body is revealed, and the failure mode of mining slope body with transverse crack, longitudinal crack and step slip is obtained. In this paper, the failure mode of "transverse four zone" of mining slope body is put forward. The strength reduction numerical model of slope stability analysis under well mining disturbance is constructed, and the deformation distribution law of mining slope body is analyzed. According to the distribution of plastic shear strain rate and deformation distribution, the evolution law of the position and shape of the critical slip surface is traced, and the influence of the working face advance on the safety factor of the mining slope is obtained. This paper provides a basis for reasonably determining the position of stoppage line in mining face. It reveals the control mechanism of overburden and deformation of mining slope by adjusting overburden on mining slope and controlling slippage of weak rock. This paper puts forward the control technology of backfilling foot, cutting slope weight and setting up anti-slide pile for different zones of mining slope in the end side coal mining, and it is successfully applied in Pingshuo mining area. There are 106 pictures, 13 tables and 203 references.
【学位授予单位】：中国矿业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TD325

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