不同采深条件下采动引起覆岩移动及松散含水层破坏的相似模拟试验研究

发布时间：2018-06-21 10:35

  本文选题：松散含水层 + 相似模拟实验　； 参考：《太原理工大学》2017年硕士论文

【摘要】：作为厚黄土覆盖区,山西是全国水资源匮乏的省份之一。厚黄土地区往往含有富水性好、厚度大的含水层,从而成为当地的主要供水水源。山西作为煤炭开采大省,大范围的煤炭的开采势必会引发较多的环境问题。煤层的开采会对上覆含水层产生影响甚至破坏,主要是由于煤炭的开采形成“三带”即冒落带、裂隙带和弯沉带,“三带”中的裂隙带和弯沉带会对覆岩以及上覆松散含水层的稳定性造成影响。另外,裂隙带的存在也会增大含水层水位下降速率,致使上覆含水层发生渗漏,水量减少,动态平衡破坏。主要表现为地下水水位下降、泉水断流、含水层疏干等生态环境破坏问题。本文以厚黄土覆盖地区的长治屯留县常村煤矿为背景,采用三组相似模拟实验,研究不同采深条件下采煤对该区覆岩移动规律及松散含水层的影响。研究采动条件下覆岩水平与垂直位移移动规律、覆岩裂隙长度与面积的变化规律以及对含松散含水层稳定性影响的规律。实验结果分析得出:覆岩的垂直与水平位移量随着采深的变化规律性较弱,各组对应观测线垂直位移量相差不大,关键层的存在会对沉降量有影响;三组模型的水平位移变化相似,垂直位移量关于开采中心线对称,规律性较强;裂隙长度与面积发育程度随着采深的增大而增大,主关键层会影响裂隙长度随采深增大而增大的规律,对裂隙面积的发育规律没有影响;同样,残余裂隙率随着采深的增大而增大,受主关键层会影响模型Ⅱ残余裂隙率发育程度最高,模型Ⅲ次之,模型Ⅰ最小;不同采深也会影响松散含水层水位下降速率突变的时间,采深越小水位下降速率突变越迅速,对上覆松散含水层的影响也就越大;最后分析得出采动通过改变隔水底板曲率影响隔水层隔水性能从而破坏松散含水层稳定结构。
[Abstract]:As a thick loess covering area, Shanxi is one of the provinces with scarce water resources. The thick loess region often contains water-rich and thick aquifer, so it becomes the main water supply source. As a big coal mining province, Shanxi is bound to cause more environmental problems. The mining of coal seam will affect or even destroy the overlying aquifer, mainly due to the formation of "three zones" of coal mining, that is, caving zone, fissure zone and bending zone. The fracture zone and deflection zone in the "three zones" will affect the stability of overlying rock and overlying loose aquifer. In addition, the existence of fissure zone will also increase the rate of aquifer water level decline, resulting in the leakage of overlying aquifer, the decrease of water volume and the destruction of dynamic balance. The main problems are the decrease of groundwater level, the breakage of spring water, the drying of aquifer and so on. Based on Changcun Coal Mine in Changzhi Tunliu County of Changzhi Loess covered area, three groups of similar simulation experiments are used to study the influence of coal mining on overburden rock movement and loose aquifer in this area under different mining depth. The law of horizontal and vertical displacement movement of overburden under mining conditions, the variation of crack length and area of overburden and the influence of overburden on the stability of loose aquifer are studied. The experimental results show that the vertical and horizontal displacement of overburden rock is weak with the mining depth, the vertical displacement of the corresponding observation line of each group is not different, and the existence of the key layer will have an effect on the settlement. The horizontal displacement of the three groups of models is similar, the vertical displacement is symmetrical to the mining center line, and the fracture length and area development degree increase with the increase of mining depth. The main critical layer will influence the law that the crack length increases with the mining depth, but has no effect on the fracture area development law, similarly, the residual fracture rate increases with the mining depth increase, The critical layer of acceptor will affect the development of residual fracture rate of model 鈪，

本文编号：2048315