鄂尔多斯盆地西缘宝塔山含水层水文地质特征

Hydrogeological Characteristics of the Baotashan Aquifer in the Western Edge of the Ordos Basin

为了避免鄂尔多斯盆地西缘煤矿发生底板砂岩水害,需要掌握区域含煤地层底部宝塔山含水层水文地质特征。通过对详查、勘探、水文地质补充勘探、放水试验等不同阶段对宝塔山含水层开展水文地质探查工作,并对各阶段探查结果进行分析,认为通过水文地质补充勘探和放水试验获取的含水层地质和水文地质条件符合实际情况。研究区宝塔山含水层的平均厚度为65m,单位涌水量和渗透系数平均值分别为0.277 1L/(s·m)和0.572 3m/d,并且富水性和渗透性表现出不均一性,宝塔山含水层水位呈现出逐渐下降的趋势,宝塔山含水层地下水属于高矿化度水。通过公式计算和放水试验分析,宝塔山含水层具有良好的可疏性。研究结果表明:研究区宝塔山含水层厚度大、水位高、富水性和渗透性较强,是威胁下组煤采掘活动的主要水害类型,可以采取疏水降压的措施来避免底板宝塔山含水层水害。

In order to avoid water damage caused by floor sandstone in the coal mines on the western edge of the Ordos Basin,it is necessary to understand the hydrogeological characteristics of the Baotashan aquifer at the bottom of the regional coal bearing strata.Through detailed survey,exploration,hydrogeological supplementary exploration,and dewatering test,hydrogeological exploration work was carried out on the Baotashan aquifer at different stages,and the exploration results of each stage were analyzed.It is believed that the geological and hydrogeological conditions of the aquifer obtained through hydrogeological supplementary exploration and dewatering test are in line with the actual situation.The average thickness of the Baotashan aquifer in the research area is 65m,with specific water yield and average permeability coefficient of 0.2771L/(s•m)and 0.5723m/d,respectively.The water abundance and permeability show non-uniformity,and the water level of the Baotashan aquifer shows a gradually decreasing trend.The groundwater in the Baotashan aquifer belongs to high salinity water.Through formula calculation and water release test analysis,the Baotashan aquifer has good sparsity.The research results indicate that the Baotashan aquifer in the study area has a large thickness,high water level,strong water abundance and permeability,and is the main type of water damage threatening the mining activities of the lower group coal.Measures such as hydrophobic pressure reduction can be taken to avoid water damage to the floor Baotashan aquifer.