湖南省界牌岭矿区矿坑充水途径研究

Study on water filling path in the Jiepailing mining area of Hunan Province

湖南省界牌岭矿区在深部多金属矿探采结合施工时,出现了矿坑涌水量大和西南部塔下村余家组发生了大量岩溶地面塌陷等问题。尽管以往开展过矿区水文地质勘查工作,但对水文地质条件尤其是威胁矿山安全生产及对周边地质环境造成破坏的矿坑潜在充水水源和充水通道了解得不够清楚。文章系统整理分析了矿区前期各阶段水文地质资料,结合地面调查、物探、钻探、抽水试验等常规方法,对界牌岭矿区水文地质条件进行了研究,并重点分析了矿坑充水途径。结果显示:(1)研究区西南部新发现NE向断层F_(303)。(2)矿坑主要充水途径有2条:①矿区西部F_(201)至F_(32)段隔水层测水组缺失,壶天群、梓门桥组与石蹬子组直接接触,同时受F_(201)、F_(303)、F_(32)的影响,构成矿坑最主要的充水途径;②矿区西北部沿花岗斑岩岩体与围岩接触带富水性较好,围岩接触带构成矿坑充水途径;主要充水水源为西部壶天群地下水和田尾溪水。建议在F_(1)的西侧梓门桥组、壶天群范围内利用下部隔水层测水组对梓门桥组、壶天群内的充水途径进行帷幕注浆,阻隔矿区与河水、壶天群的地下水水力联系。研究结果可为矿山下一步防治水工作的实施提供参考依据。

In the Jiepailing mining area,during the exploration and mining of deep polymetallic ores,the water filling in the pits and extensive karst ground collapses in the Yujia area occurred.Although previous studies have investigated the hydrogeological conditions in the mining area,the potential sources and pathways of water filling that threaten mine safety and damage the surrounding geological environment,are not clear.This study investigated the hydrogeological conditions and analyzed the pathways of water filling in the Jiepailing mining area by using systematical analysis of hydrogeological data from various stages,ground surface investigation,geophysical exploration,drilling,and pumping tests.The results show that:(1)the northeastern fault F_(303) is found,loocated in the southwestern part of the study area.(2)In the western part of the mining area the absence of the aquifuge between F_(201) and F_(32) leads to Shidengzi Formation directly contacting the Hutian Group and Zimenqiao Formation.It constitutes the main pathway of water filling in the mine pits,affected by F_(201),F_(303),and F_(32).In the northwestern part of the mining area,the contact zone between the granodiorite porphyry and the surrounding rock has good water-richness,forming the other pathway for water filling in the mine pits.The main sources of water filling are the groundwater in the western Hutian Group and Tianweixi river water.This study suggests executing curtain grouting on the west side of F_(1) by the lower impermeable layer group to block water pathways within the Hutian Group of the Zimenqiao Formation,thereby interrupting the hydraulic connection between the mining area and the river water,as well as groundwater in the Hutian Group.The results can provide basic information for the implementation of water prevention and control in the mine area.