西部弱胶结地层大采高工作面覆岩结构演化与矿压活动规律研究

发布时间：2018-09-10 10:19

【摘要】：随着我国西部大开发的快速发展,近期西部大批开采弱胶结地层煤炭资源矿井陆续建成投产,弱胶结地层天然的禀赋条件决定了其物理力学性能与中东部岩层有明显的差异,开采实践表明弱胶结地层大采高工作面矿压活动规律与中东部大采高工作面矿压活动规律也有一定的差异。因对弱胶结地层性能和工作面矿压活动规律认识不清,导致弱胶结地层大采高工作面开采时常发生大面积冒顶、台阶下沉、溃水溃沙、支架压死等事故。因此,弱胶结地层大采高工作面覆岩运动、三带分布、支架选型等矿压问题亟需解决。本文以红庆河煤矿弱胶结地层大采高工作面开采为工程背景,通过实验室实验、数值模拟、相似材料模拟、理论分析及现场实测等方法,研究了弱胶结岩石物理力学性能及其与中东部岩石的差异性,统计了弱胶结煤系地层地域分布;分析了弱胶结岩石受开采扰动在采空区破碎、冒落、充填、崩解、压实、固结的变形规律;构建了弱胶结地层大采高工作面覆岩结构演化模型,揭示了弱胶结地层大采高工作面冒落带分布特征及其与裂隙带协同演化规律;研究了围岩-支架之间的作用机理,给出了弱胶结地层大采高工作面支架工作阻力计算方法。取得主要研究成果包括:(1)弱胶结岩石具有强度低、胶结性差、遇水泥化、易崩解等特性,我国新疆、神东、蒙东、宁东、陕北等煤矿区具有弱胶结地层开采条件,基于弱胶结岩石的力学参数、物理参数、成岩年代等因素,对西部典型矿区弱胶结岩石进行了变异性评价。(2)针对弱胶结岩石与中东部岩石碎胀性、崩解性的差异,通过碎胀实验和崩解实验,研究了弱胶结岩石的初始碎胀性、残余碎胀性特征及其耐崩解特征,揭示了弱胶结岩石强碎胀、易崩解的特性。(3)针对西部弱胶结岩石物理力学性能与中东部岩石的差异性,通过实验和理论分析,研究了开采扰动作用下弱胶结岩石变形、破坏、冒落、崩解、压实、固结等特征,分析了弱胶结岩石破碎-冒落-充填-崩解-再破碎-压实-固结的变形规律,揭示了弱胶结地层冒落充填体的变形演化机理。(4)以红庆河煤矿3-1煤首采面为工程背景,通过相似材料模拟、数值模拟及理论分析,研究了弱胶结地层大采高工作面覆岩运动规律及应力场分布规律,获得了覆岩由下至上层层递进的冒落特征,揭示了覆岩裂隙萌生-发展-贯通的岩层破坏机理。(5)根据弱胶结地层的物理力学性能和充填体变形机制,通过相似材料模拟和理论分析,研究了弱胶结地层大采高工作面覆岩变形、运动规律,建立了弱胶结地层大采高工作面覆岩裂隙演化模型,研究了三类顶板结构下大采高工作面冒落带分布特征,获得了弱胶结地层大采高工作面冒落带分布规律,揭示了冒落带与裂隙带协同演化机制。(6)根据弱胶结地层大采高工作面"三带"分布特征和演化规律,研究了弱胶结地层大采高工作面矿压活动规律,分析了支架-围岩之间相互作用机理,给出了弱胶结地层大采高支架工作阻力计算方法,现场实测数据初步验证该方法的合理性和实用性。论文初步探索了弱胶结岩石的物理力学性能、弱胶结地层大采高工作面覆岩结构演化规律及三带分布规律,但受西部矿区地域辽阔及复杂地质条件的影响,下一步还需要针对一个矿区内弱胶结岩石的物理力学性能进行深入研究,并开展大量的现场矿压观测,进一步揭示西部弱胶结地层大采高工作面矿压活动规律。
[Abstract]:With the rapid development of Western China, a large number of coal mines exploiting weak cemented strata have been built and put into operation in recent years. The natural endowment conditions of weak cemented strata determine that their physical and mechanical properties are obviously different from those of the middle and Eastern strata. Mining practice shows that the law of ground pressure activity in high mining face with weak cemented strata and the middle level. There are also some differences in the law of ground pressure activity in the large mining height face in eastern China. Because of the unclear understanding of the performance of weak cemented strata and the law of ground pressure activity in the working face, large area roof caving, bench subsidence, water bursting and sand bursting often occur in the large mining height face in weak cemented strata. Rock movement, three-zone distribution, support selection and other rock pressure problems need to be solved urgently. Based on the mining of high mining face in weak cemented strata in Hongqinghe Coal Mine, this paper studies the physical and mechanical properties of weak cemented rock and its relationship with rocks in the middle and eastern part of China through laboratory experiments, numerical simulation, simulation of similar materials, theoretical analysis and field measurement. The regional distribution of weak cemented coal measure strata is statistically analyzed; the deformation law of weak cemented rock broken, caving, filling, disintegration, compaction and consolidation in goaf under mining disturbance is analyzed; the evolution model of overlying rock structure in large mining height face in weak cemented strata is constructed, and the distribution characteristics of caving zone in large mining height face in weak cemented strata are revealed. The main research results are as follows: (1) Weak cemented rock has the characteristics of low strength, poor cementation, cement, easy disintegration, Xinjiang, Shendong, Mengdong, Ningdong, Shaanxi, etc. Based on the mechanical parameters, physical parameters and diagenetic age of weak cemented rocks, the variability of weak cemented rocks in typical mining areas in Western China is evaluated. (2) According to the difference of fragmentation and disintegration between weak cemented rocks and those in eastern and central China, the fragmentation and disintegration experiments are carried out to study the fragmentation and disintegration of weak cemented rocks. The characteristics of initial dilatancy, residual dilatancy and anti-disintegration of cemented rocks reveal the characteristics of strong dilatancy and easy disintegration of weakly cemented rocks. (3) Aiming at the differences of physical and mechanical properties between the weakly cemented rocks in the West and the rocks in the middle and eastern parts of China, the deformation, failure and caving of weakly cemented rocks under mining disturbance are studied experimentally and theoretically. The deformation law of fragmentation-caving-filling-disintegration-re-fragmentation-compaction-consolidation of weakly cemented rock is analyzed, and the deformation evolution mechanism of caving-filling body in weakly cemented strata is revealed. (4) Based on the engineering background of No. 3-1 coal face in Hongqinghe Coal Mine, the similar material simulation, numerical simulation and theoretical analysis are carried out to study the deformation mechanism of caving-filling body in weakly cemented strata. The movement law and stress field distribution law of overlying rock in large mining height face of weak cemented stratum are obtained, and the progressive caving characteristics of overlying rock from bottom to upper stratum are obtained. The failure mechanism of overlying rock fracture initiation-development-penetration is revealed. (5) According to the physical and mechanical properties of weak cemented stratum and the deformation mechanism of filling body, the similar material simulation and theory are adopted. This paper analyzes and studies the deformation and movement law of overlying strata in large mining height working face with weak cemented strata, establishes the evolution model of overlying strata fracture in large mining height working face with weak cemented strata, studies the distribution characteristics of caving zone in large mining height working face with three types of roof structure, obtains the distribution law of caving zone in large mining height working face with weak cemented strata, and reveals the caving zone and caving zone. (6) According to the distribution characteristics and evolution law of "three zones" in large mining height face of weak cemented stratum, the law of ground pressure activity in large mining height face of weak cemented stratum is studied, the mechanism of interaction between support and surrounding rock is analyzed, the calculation method of working resistance of large mining height support in weak cemented stratum is given, and the field measured data are preliminary. The rationality and practicability of this method are verified step by step. The physical and mechanical properties of weak cemented rock, the evolution law of overlying rock structure and the distribution law of three zones in high mining face with weak cemented strata are preliminarily explored. But affected by the vast area and complicated geological conditions in the western mining area, the next step is to target at the weak cemented rock in a mining area. Physical and mechanical properties of deep research, and carry out a large number of in-situ pressure observation, further reveal the Western weak cemented strata high mining face rock pressure activity law.
【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TD323

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