陕北典型煤矿开采引起含水层破坏机理物理模拟试验研究

发布时间：2018-05-29 14:14

本文选题：榆神府矿区 + 浅埋煤层　；参考：《长安大学》2015年硕士论文

【摘要】：榆神府矿区属于鄂尔多斯侏罗纪煤田的一部分,地处陕西省北部黄土高原和毛乌素沙漠的过渡地带。区内储存煤炭资源丰富,拥有我国目前最大已探明煤炭储量,是我国重要的能源基地。但陕北地区气候恶劣,干旱少雨,水资源稀缺,生态环境十分脆弱。区内含水地层少,萨拉乌苏组是主要的含水层和生态系统供给水源。矿区煤炭开采对含水层的破坏和环境污染不仅影响着居民的生活生产等活动,还严重威胁着陕北的生态平衡,关系到陕北地区和国家经济的可持续发展。本文通过对榆神府矿区相关资料的调查和研究,对矿区煤炭的埋藏地质环境进行分类和概化,并据此设计多煤层开采方法。在此基础上开展了四组物理模型试验和三组数值模拟计算。以此得出陕北矿区上覆地层在多煤层开采条件下的破坏规律和水体变化特征。试验取得成果如下:(1)矿区煤层类型为地表厚松散层浅埋煤层,试验中覆岩破坏方式是全厚层切落。在首采煤层留煤柱的情况下,覆岩“三带”发育高度低,下煤层的采动将会导致上煤层顶板岩层全厚层切落。(2)试验表明,在含水层下含隔水粘土层时,首采煤层采空区合理留设煤柱,能有效阻止导水裂隙的形成,保持水分。在无煤柱或缺少粘土层的情况下,导水裂隙将连同含水层,疏干水体。(3)在首采煤层留煤柱的情况下,通常开切眼和收割线上方发育剪切裂隙,工作面推进过程中发育在煤柱上方的裂隙一般为拉裂隙;在不留煤柱的情况下,岩层中的裂隙多为剪切作用产生。(4)采空区地表呈现台阶式下沉。含粘土层煤层上覆地层埋深越深,下沉量越大。岩层下沉受煤柱影响较大,隔粘土层和含水层的下沉量受煤柱影响较小。不含粘土层的煤层覆岩不同深度下降较为一致。
[Abstract]:Yushenfu mining area is a part of Jurassic coal field in Ordos, located in the transitional zone of Loess Plateau and Maowusu Desert in northern Shaanxi Province. The region is rich in coal resources and has the largest proven coal reserves in China, which is an important energy base in China. However, the climate in northern Shaanxi is harsh, drought is less, water resources are scarce, and the ecological environment is very fragile. The Sarawusu formation is the main source of water for aquifers and ecosystems. The destruction of aquifer and environmental pollution caused by coal mining in mining area not only affect the activities such as living and production of residents, but also threaten the ecological balance of northern Shaanxi seriously, which is related to the sustainable development of economy in northern Shaanxi. Based on the investigation and study of the relevant data of Yushenfu mining area, this paper classifies and generalizes the buried geological environment of coal in the mining area, and designs the mining method of multiple coal seams accordingly. On this basis, four groups of physical model tests and three groups of numerical simulation were carried out. The damage law and water body change characteristics of the overlying strata in the mining area of northern Shaanxi are obtained under the condition of multi coal seam mining. The results of the test are as follows: (1) the coal seam type in the mining area is shallow coal seam with thick loose layer, and the failure mode of overburden rock in the test is the cutting of the whole thick layer. When the coal pillar is left in the first coal seam, the height of the overburden "three zones" is low, and the mining movement of the lower coal seam will result in the cut off of the whole thick strata of the roof of the upper coal seam. The test shows that when there are water-separated clay layers under the aquifer, The reasonable setting of coal pillar in goaf of first coal seam can effectively prevent the formation of water conduction fissure and maintain water content. In the absence of a coal pillar or clay layer, the water-conducting fissure, together with the aquifer, dredge the water body and keep the coal pillar in the first coal seam, usually develops shear fractures above the cutting hole and the harvesting line, In the process of working face advance, the cracks developed above the coal pillar are generally tension cracks; in the case of no coal pillar, the cracks in the strata are mostly caused by shearing. 4) the surface of the goaf presents a step type subsidence. The deeper the overlying stratum is, the greater the subsidence is. The subsidence of strata is greatly affected by coal pillars, and the subsidence of separated clay layers and aquifers is less affected by coal pillars. The different depth of overburden in coal seam without clay layer is more consistent.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P641.4

【相似文献】