隧洞施工和持续干旱对岩溶地下水影响的定量评价  

Quantitative Evaluation of the Effects of Tunnel Construction and Drought on Karst Groundwater

作　　者：秦蜂 詹双桥 郑小康 陈运财 杜兴武 杨志兵 QIN Feng;ZHAN Shuang-qiao;ZHENG Xiao-kang;CHEN Yun-cai;DU Xing-wu;YANG Zhi-bing(State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430000,Hubei Province,China;Hunan Water Resources and Hydropower Survey,Design,Planning and Research Co.,Ltd.Changsha 410007,Hunan Province,China)

机构地区：[1]武汉大学水资源工程与调度全国重点实验室,湖北武汉430000 [2]湖南省水利水电勘测设计规划研究总院有限公司,湖南长沙410007

出　　处：《中国农村水利水电》2024年第5期137-146,共10页China Rural Water and Hydropower

基　　金：国家自然科学基金项目(42077177);犬木塘水库工程科技创新项目(W-2022-72)。

摘　　要：隧洞施工和持续干旱导致岩溶地区地下水位大幅下降会造成严重的生态和环境问题。因此,定量评估两种因素共同影响下的岩溶地下水系统响应有助于施工单位和居民采取有效应对措施。研究采用离散管道-连续介质耦合模型方法,建立了考虑动态施工条件下的九龙岭长隧洞工程区岩溶地下水三维数值模型,并通过工程区水文地质资料和监测钻孔水位数据对模型进行校准,用控制单一影响因素方法分别评价了在2022年8月至2022年10月隧洞施工和极端干旱两种因素对区域岩溶地下水系统的影响。结果表明,研究区域均衡期内地下水位受干旱影响范围占研究区域面积的55.43%(约649.72 km2),是隧洞施工影响的35.1倍,持续干旱是造成研究区域大面积地下水下降的主要原因;随着干旱持续,隧洞沿线整体地下水位下降受干旱影响较大,但在少量局部洞段隧洞轴线上方(如距隧洞入口14~15 km、18~19 km段)水位下降是受隧洞突涌水不同程度的影响;通过对研究区域地下水水量平衡分析发现,在均衡期内干旱影响的补给减量约为824.5万m^(3),明显多于隧洞涌水造成的地下水流失量,持续干旱对研究区域地下水的影响最大。本文阐明了在隧洞施工和干旱共同影响下岩溶地下水系统扰动的时空演变特征,研究成果可为岩溶区地下工程影响评价提供参考依据。Tunnel construction and continuous drought both can cause significant decrease in groundwater level in karst regions,which can bring serious ecological and environmental issues.Thus,a quantitative evaluation of the influence of these two factors on karst groundwater system is important for engineers and local residents to take effective countermeasures.In this study,the coupled discrete conduit-continuum model method was used to establish a three-dimensional numerical model considering dynamic construction progress in the Jiulongling tunnel construction region.The model was calibrated by using hydrogeological information of study area and available observations.The effects of tunnel construction and drought on the groundwater system during August-October 2022 were evaluated by using the method of controlling single influencing factor.The results showed that the range of groundwater levels affected by drought during the equilibrium period of the study area accounts for 55.43%(about 649.72 km2),which is 35.1 times of the impact of tunnel construction,which indicates that the drought was the main reason for the lowering of the groundwater level in the study area.With the continuous drought,the overall decline of groundwater level along the tunnel was mainly affected by drought,but the significant decline of water level at some sporadic locations above(such as 14~15 km,18~19 km from the tunnel entrance)the tunnel axis could be attributed to the water inrush into a tunnel segment under construction.According to water balance analysis,during the equilibrium period of August-October 2022,the reduction in recharge due to drought was about 8.245×10^(6) m^(3),which was significantly more than the groundwater loss caused by tunnel inrush,and the continuous drought had the greatest impact on the groundwater in the study area.This work demonstrates the impacts of underground engineering activities and drought on spatial and temporal evolutions of karst groundwater,and can provide guidance and reference for the hydrogeologica

关 键 词：岩溶地下水 数值模拟 隧洞施工 持续干旱 定量评价 

分 类 号：TV67[水利工程—水利水电工程]