【作者】 孟超；

【导师】 李学华；

【作者基本信息】 中国矿业大学 ， 采矿工程， 2013， 博士

【摘要】 我国厚煤层储量丰富，大采高综采随着技术优点的日益突出和配套设备的重大进展，已成为厚煤层开采的重要发展方向。但当大采高工作面遇到大倾角等复杂煤层赋存条件，将造成采场围岩控制的难度增大，特别是工作面煤壁易于片帮失稳，严重制约了大采高工作面安全高效优势的发挥。因此，开展大倾角大采高工作面煤壁失稳机理及控制研究具有重要现实与理论意义。论文调查统计了大采高工作面煤壁失稳的主要形式及其失稳特点，根据大采高工作面煤壁失稳的不同机制，对大采高工作面煤壁失稳进行了科学分类，提出了应力控制型煤壁失稳和结构控制型煤壁失稳的概念，并解释了其内涵。采用弹性力学的基本理论，对应力控制型煤壁失稳机理进行了理论研究，分析了工作面煤壁前方煤体内的应力分布规律。根据工作面前方煤体内最大主应力和最大剪应力的分布规律，发现在在大采高工作面煤壁中部偏上部位易发生拉裂破坏机制造成的应力控制型煤壁，在工作面煤壁上部易发生剪切破坏机制造成的应力控制型煤壁失稳。采用楔形体滑动破坏理论并结合极限平衡法，对结构控制型煤壁失稳机理进行了理论研究，得到了结构控制型煤壁失稳的判别式。根据岩石力学中结构面的强度效应，建立了结构控制型煤壁失稳与应力控制型煤壁失稳的判别机制。采用理论研究、RFPA数值模拟、PFC数值模拟、UDEC数值模拟方法，深入研究了煤层倾角对大采高工作面应力控制型煤壁稳定性和结构控制型煤壁稳定性的影响，得到了不同采高、不同煤体强度、不同埋深、不同结构面产状等条件下，煤层倾角对煤壁稳定性的影响规律，为大倾角大采高工作面煤壁稳定性控制提供了技术思路。运用AHP-FCE综合评判模型，对羊场湾煤矿Y110206大采高工作面煤壁稳定性进行了评价。依据煤层赋存条件和大采高综采技术及装备水平，对Y110206工作面进行了合理设计和设备选型，提出了大倾角复杂特厚易燃煤层6.2m大采高工作面的安全保障技术，实现了工作面年产量达到了1000万t的预期目标，技术经济效益显著。更多还原

【Abstract】 Due to abundant reserves of thick coal seam in our country, fully-mechanizedmining of coalface with great mining height, with increasingly prominent merits of itstechnology and significant improvement of the matching equipment, has alreadybecome the important development direction in terms of the mining of thick coal seam.However, the complicated occurrence conditions, such as the increase of the dip angleand the buried depth of the coal seam, and―three softness‖coal seam, pose greatchallenge for controlling the surrounding rock of the stope, leading to serious instabilityof the coal wall in the coalface, which greatly limit the exertion of the of advantages ofsafe and high-efficient mining of coalface with great mining height. Therefore,launching studies on the stability of the coal wall and the technology for safe andhigh-efficient mining in coalface with great mining height is of great realistic andtheoretical significances.Based on the investigations and statistics of the main instability forms of the coalwall and its instability characteristics, in view of the different mechanisms of theinstability of the coal wall in the coalface with great mining height, the present paperconducts scientific classifications of the instabilities, puts forward the concept ofstress-controlled instability and structure-controlled instability, and interprets theirconnotations.With the adoption of fundamental theories in elasticity, the present paper conductstheoretical studies to investigate the mechanism of the stress-controlled instability of thecoal wall, and analyzes the stress distribution law in the coal mass in front of thecoalface. According to the distribution law of the maximum principle stressσ1andmaximum shear stressτmax in the coal mass in front of the coalface, the author findsthat the splitting failure, leading to stress-controlled instability，is very likely to happenin the middle and upper part of the coal wall in coalface with great mining height, andthe shear failure, leading to structure-controlled instability, is likely to happen in theupper part of the coal wall. Using slide failure theory of wedge-shaped object combinedwith limit equilibrium method, we launch theoretical studies on the mechanism ofstructure-controlled instability, obtaining its judgment equation. In line with the volumeeffects of the structural plane in rock mechanics, we established the discriminantmechanism of stress-controlled instability and structure-controlled instability of the coalwall. Using theoretical studies, RFPA and PFC and UDEC numerical software, thepresent paper studies deep into the influences of the coal seam dip angle on the stress-controlled instability and structure-controlled instability of the coal wall incoalface with great mining height, acquiring its influencing law under followingconditions, different mining height, different coal mass intensity, different buried depthand different occurrence of structural planes, et al, providing technical train of thoughtfor controlling the stability of the coal wall in coalface with great mining height andlarge dip angle. Utilizing AHP-FCE comprehensive evaluation model, this paperconducts the evaluation of the stability of the Y110206coalface with great miningheight in Yangchangwan coal mine. According to the occurrence of the seam and thefully-mechanized technology of the coalface with great mining height as well as itsequipped level, the present paper conducts reasonable designing and equipmentselection, puts forward the security technology for the coalface with6.2m height andlarge dip angle and free burning seam, realizes the expected goal of producing10million of the coal, yielding significant technical and economic benefits.更多还原