浅埋煤层大采高综采面顺槽围岩破坏机理及其支护技术

发布时间：2018-05-04 03:38

  本文选题：浅埋煤层 + 破坏机理　； 参考：《西安科技大学》2017年硕士论文

【摘要】：开展陕北地区浅埋煤层顺槽围岩破坏机理和顶板稳定性分级及支护技术研究具有重要的工程应用价值。本文以神南矿区某矿5-2煤顺槽支护工程为依托,采用理论分析、室内试验、数值模拟以及现场实测相结合的方式对矩形顺槽顶板破坏机理、顶板稳定性分级以及顺槽支护技术等进行了研究。主要工作和结论有:(1)分析了浅埋煤层矩形顺槽顶板破坏形式和影响顶板稳定性的主要因素,主要破坏形式有张拉破坏、剪切破坏、局部落石破坏以及复合破坏。影响顺槽顶板稳定性的主要因素有地质条件、采动影响、地下水、断面尺寸、埋深以及地应力等。在此基础上建立矩形顺槽顶板力学模型,分析了顺槽顶板破坏机理。(2)结合顺槽顶板稳定性主要影响因素,选取了顶板岩样饱和单轴抗压强度、煤样饱和单轴抗压强度、岩体完整性指标、顺槽埋深、顺槽跨度、顺槽高度和采高作为顶板稳定性分级的指标。针对神南某矿5-2煤工程地质条件,将顺槽顶板稳定性分为Ⅰ级顶板(稳定)、Ⅱ级顶板(中等稳定)和Ⅲ级顶板(不稳定)。根据悬吊理论和组合梁理论,结合已掘顺槽支护效果反馈,确定了各级顶板的顺槽支护参数。(3)对1506工作面顺槽顶板煤岩样进行了物理力学试验,得到了煤岩样在自然与饱水状态下的物理力学参数。通过层次分析法得到了各指标权值,采用模糊综合评判法,根据最大隶属度原则判定1506工作面胶运顺槽和辅运顺槽顶板稳定性等级为Ⅰ级(稳定顶板),需采取Ⅰ级顶板支护参数进行支护。由现场实测数据分析可知,1506工作面顺槽掘进和工作面回采期间顺槽变形量较小,锚杆最大受力30.2kN,顺槽支护效果较好,满足工作面安全回采需求。(4)采用有限差分软件FLAC~(3D)对5-2煤顺槽各级顶板支护效果进行了模拟,结果表明,Ⅰ、Ⅱ、Ⅲ级顶板在掘进和回采期间顺槽变形和塑性区范围均较小,满足顺槽支护要求。本文研究浅埋煤层矩形顺槽顶板破坏机理和顶板稳定性分级及支护技术,可为该地区其他矿顺槽支护工作提供参考。
[Abstract]:It is of great value to study the failure mechanism, roof stability classification and supporting technology of shallow coal seams in northern Shaanxi. In this paper, based on the supporting engineering of 5-2 coal seam in Shennan mining area, the failure mechanism of rectangular roof along the slot is analyzed by theoretical analysis, laboratory test, numerical simulation and field measurement. The classification of roof stability and the technique of supporting along grooves are studied. The main work and conclusion are as follows: (1) analyzing the failure form of shallow coal seam rectangular trench roof and the main factors affecting roof stability, the main failure forms are tensioning failure, shearing failure, local rock falling failure and composite failure. The main factors affecting the stability of the roof along the channel are geological conditions, mining effects, groundwater, cross-section size, depth of burial and in-situ stress. On this basis, the mechanical model of rectangular slotted roof is established, and the failure mechanism of shunt roof is analyzed. Combined with the main influencing factors of the stability of the down-grooved roof, the saturated uniaxial compressive strength of roof rock sample and the saturated uniaxial compressive strength of coal sample are selected. The indexes of rock integrity, buried depth, span, height and mining height are the indexes of roof stability classification. According to the engineering geological conditions of 5-2 coal in Shennan coal mine, the stability of the shun trough roof is divided into class 鈪，

本文编号：1841438