摘要
依托南京地铁4号线桦墅站-仙林东站区间设中间风井的抽水试验,在分析场区的工程地质与水文地质特征的基础上,采用抽水试验与水文观测孔相结合的方法,对中间风井基坑的主要水源层周冲村组灰岩承压含水层进行水文试验。依据现场测试成果,基于VISUAL MODFLOW软件,创建地下水系统的水文地质数值模型,并进行模型的校正与识别,进而得出研究区的水文地质参数。研究表明,经水位拟合及反演计算,数值模型计算值和抽水试验观测值的总体变化趋势一致,其参数可用于模型预报。经计算,灰岩裂隙含水层平均导水系数418.6 m^(2)/d,平均储水系数4.20×10^(-5),平均渗透系数12.9 m/d;影响半径在水位降深为19.56 m时约为703 m。研究成果可为灰岩地区求取承压含水层的水文地质参数提供参考,为确定地下工程开挖的涌水量预测提供科学依据。
Based on the pumping test of the middle air shaft between Huashu station and Xianlin east station of Nanjing Metro Line 4,based on the analysis of the engineering geology and hydrogeological characteristics of the site,the method of combining pumping test with hydrological observation hole is used to carry out the hydrological test on the limestone confined aquifer of zhouchongcun formation,the main water source layer of the middle air shaft foundation pit,based on VISUAL MODFLOW software,the hydrogeological numerical model of groundwater system is created,and the model is corrected and identified,and then the hydrogeological parameters of the study area are obtained.The results show that the trend of the numerical model is consistent with that of the pumping test,and its parameters can be used for model prediction;after calculation,the average hydraulic conductivity of limestone fractured aquifer is 418.6 m^(2)/d,and the average water storage coefficient is 4.20×10^(-5).The average permeability coefficient is 12.9 m/d;the influence radius is 703 m when the water level drops 19.56 m.The research results can provide a reference for obtaining the hydrogeological parameters of confined aquifer in limestone area,and provide a scientific basis for determining the water inflow prediction of underground engineering excavation.
作者
吕红娟
LÜ Hong-juan(The Seventh Geological Brigade of Hebei Bureau of Geology and Mineral,Sanhe 065201,Hebei,China)
出处
《水利科技与经济》
2021年第12期11-17,共7页
Water Conservancy Science and Technology and Economy
关键词
抽水试验
承压含水层
水文地质参数
灰岩
pumping tests
confined aquifer strata
hydrogeological parameters
Karst
