【作者】 刘玉德；

【导师】 张东升；

【作者基本信息】 中国矿业大学 ， 矿业工程， 2008， 博士

【摘要】 我国西部煤炭开发区具有煤层浅埋、水资源短缺、环境脆弱的特征,在大规模开采条件下,保水开采是一事关西部矿区可持续发展的核心保障技术。论文深入分析了国内外研究现状,并基于神东煤田的地质条件,采用理论分析、物理模拟、数值计算、三维固液耦合模拟等方法和手段,对浅埋煤层覆岩移动规律和裂隙分布特征进行了综合研究,从理论上分析了浅埋煤层保水开采的机理,由此确定了保水开采的关键,找出了浅埋煤层保水开采的基本条件,初步形成了一套以工作面快速推进、工作面有效支护及工作面局部防渗处理为核心的浅埋煤层保水开采技术。在此基础上,进一步对沙基型浅埋煤层保水开采适用条件进行了细致地分类,计算并开发了各分类相应的技术工艺与参数,并将其成功应用于保水开采的工程实践。主要研究成果如下:(1)初步形成沙基型浅埋煤层保水开采的分类体系。尝试采用多因素综合指标分析方法,对浅埋煤层保水开采条件进行分类。以裂隙带高度作为综合指标,以岩层综合强度、岩体完整性指数、采动影响指数作为相关因素,推导出长壁工作面和短壁工作面导水裂隙带高度的计算公式,并根据覆岩裂高、岩柱与基岩厚度的不同,把沙基型浅埋煤层划分为三个类别、七个区域(安全防水区、长壁容易区、长壁中等区、长壁困难区、短壁多硐连续区、短壁多硐间隔区、短壁单一采硐区)。(2)初步形成沙基型浅埋煤层保水开采的技术体系。首次提出“渗流确定采速”的方法和开切眼处“台阶式渐进开采”方式,创新出短壁连采工作面三种布置模式:多硐连续式、多硐间隔式、单一采硐式,并针对保水开采各分类的特征,确定出相应的技术工艺与参数。研究表明:长壁面保水开采适宜速度为10～25 m/d、切眼台阶渐进范围大于200 m、采高4.0～6.0 m、支护阻力为5000～8500 kN;短壁面保水开采适宜速度大于35 m/d、台阶渐进范围大于150 m、采高为3.0～6.0 m、支护阻力为7500～9500 kN。(3)沙基型浅埋煤层保水开采的分类体系与技术体系在神东矿区浅埋煤层32201、12404工作面保水开采工程实践中的应用表明:采动对上覆含水层的超前影响范围一般为20.0 m,水位受采动影响下降5～10 m左右,最大下降幅度4 m/d左右;采后3～4 d水位便开始回升,在4～15 d内水位回升最快,回升率0.1～0.3 m/d,50 d左右便基本趋于稳定。工作面安全推过强富水区。更多还原

【Abstract】 Western Coalmine Area of China has the characteristic of shallow coal seam,short water source and vulnerable entironment. So aquifer-protective mining might be one key safeguarding technology that has a bearing on continuous development of Western Coalmine Area when a large scale of exploitation is in progress. Therefore, on the base of geological condition of Shendong Coalfield and the analyse of status both at home and abroad, the moving law of overlying strata & the distributing characteristic of crannies above shallow coal seam have aggregately been analyzed by means of many methods & measures, such as theoretical analyse, physical simulation, numerical calculation, three-dimensional solid-liquid coupling simulation etc. And the rationale of aquifer protective mining in shallow sand-bedrock-coal seam has been analyzed in theory. Then the linchpin & basic qualification of aquifer protective mining have been brought forward. Consequently, a preliminary suit of aquifer protective mining technology, which takes rapid advancing, rational support and partial impervious measure of working face for its core, has been formed. The useable conditions have been classified carefully. Moreover, relative technics & parameters of aquifer protective mining in shallow sand-bedrock-coal seam has been calculated and innovated, and been applied in engineering practice of aquifer protective mining successfully.Innovative achievements of this dissertation have been displayed as follows:(a) The analytical method of synthetic index with multi-factors has been selected to attempt classify the condition applied to aquifer protective mining in shallow coal seam. Height of water transmitting crannies has been selected as the synthetic index of classification. Synthetic intensity of overlying strata, mining disturbing influence & integrity of strata have been taken for primary relative factors of synthetic classifying index. Moreover, the calculative formulation of water transmitting crannies’height in long-wall & short-wall working face respectively has been derived. Then the shallow sand-bedrock-coal seam has been classified to three sorts or seven regions (i.e. secures waterproof mining section; easy mining section of long wall, moderate mining section of long wall, difficult mining section of long wall; continuous multi-rooms section of short wall, placed multi-rooms section of short wall, and single room section of short wall) by aggregate comparison among height of cranny zone, ribbon of rock and thickness of bedrock. Consequently, the classifying system of aquifer protective mining in shallow sand-bedrock-coal seam has been educed.(b) The method of defining mining velocity by seepage velocity & the model of sidestep advancing mining at open-off cut has been put forward for the first time. And new arrangement mode of short wall continuous mechanical mining working face (Continuous multi-rooms, placed multi-rooms and single room of lay-out pattern) has been innovated. And aiming at each sort character of aquifer protective mining, the technical parameters & technics of each sort condition have been educed. Consequently the technical system of aquifer protective mining in shallow sand-bedrock-coal seam has been formed. It has been shown that in long-wall working face, the rational advancing velocity of aquifer protective mining is about from 10 meters to 25 meters per day, the adjusting scope of sidestep advavcing mining at open-off cut is generally more than 200 meters, the mining height is from 4 meters to 6 meters, and the supporting force might be from 5000 kN to 8500 kN; while, in short-wall working face, the rational advancing velocity of aquifer protective mining is more than 35 meters per day, the adjusting scope of sidestep advavcing mining at open-off cut is more than 150 meters, the mining height is from 3 meters to 6 meters, and the supporting force might be from 7500 kN to 9500 kN.(c) Engineering practice of aquifer proactive mining in working faces No. 32201 & No. 12404 respectively has been done in intensive water-bearing area of Shendong Mine Area by using the classifying system & technical system of aquifer protective mining. And the aquifer protective mining in this working faces has been successful. It has been shown by observation on-site & analysis of data that pre-affected scope on overlying aquifer due to mining is commonly 20 meters, while, ground water above working face might be infiltrated down quickly. Along with the close of key rock block, water level begins to rise again after 3 days or 4 days, and recovers at the fastest velocity after from 4 days to 15 days; recovery ratio is from 0.1 to 0.3 meter per day. Water level might be driven to stable after about 50 days. Two working face has passed successfully through intensive water-bearing area of safety.更多还原