煤矿开采导水裂隙带发育对潜水水位影响研究

Study on impact from development of coal mining fractured water-conducting zone on phreatic water level

为定量阐述采煤导水裂隙带发育对潜水含水层的影响,在分析采煤导水裂隙带发育形成机理的基础上,依据采煤导水裂隙带发育对潜水含水层的影响进行分类研究,按照对潜水水位影响的程度分为两类模式。基于这两种分类模式,以锦界矿区为研究对象,建立考虑导水裂隙带发育的地下水数值模拟模型,利用大量实测水位反演出导水裂隙带影响下各分区垂向渗透系数值变化序列,以此反映导水裂隙带发育对潜水含水层的影响。通过构建的地下水数值模型计算表明,在分类模式二条件下,由于导水裂隙带导通潜水关键隔水层构成垂向渗漏通道,隔水层垂向渗透系数显著增大,潜水水位形成大范围地下水降落漏斗。开采前10年最大降深值28 m,降深大于20 m的影响严重区域面积约为2.56 km^2,开采后20年,潜水位最大降深达到32 m。

Study on impact from development of coal mining fractured water-conducting zone on phreatic water level GUO Xinwei, DONG Guotao, HE Hongmou, YIN Huijuan （Yellow River Institute of Hydraulic Research, Zhengzhou 450003, Henan, China） Abstract： In order to quantitively expatiate the impact from coal mining fractured water-conducting zone on phreatic aquifer, a study is made on the classified modes in accordance with the impact from coal mining fractured water-conducting zone on phreatie aquifer based on the analysis of the forming mechanism of the development of the coal mining fractured water-conducting zone, for which the degree of the impact on the phreatic water level is divided into two classified modes. On the basis of the study on the classified mode, a groundwater numerical simulation model with the consideration of the development of the fractured water-con- ducting zone is established by taking Jinjie Coal Mine Area as the study object, from which the variation sequence of the vertical hydraulic conductivity values within all the sub-zones under the impact of the fractured water-conducting zone is inversed with large amount of measured data of the water level, so as to reflect the impact from the development of the fractured water-conduc- ting zone on phreatie aquifer. The calculation made through establishing groundwater numerical simulation model indicates that under the classified mode II, a vertical seepage passage is formed, since the fractured water-conducting zone is conducted through the key aquifuge therein, and then the vertical hydraulic conductivity is significantly increased and the phreatic water level forms a large range of groundwater depression cone. 10 years before the coal mining, the maximum drawdown is 28 m and the area under the serious impact from the drawdown of larger than 20 m is about 2. 56 km^2, but 20 years after the coal mining, the depth of the maximum drawdown of the phreatic water level reaches to 32 m.