柳家村隧洞水化学特征分析及涌水水源判别方法研究

Study on hydrochemical characteristics and discrimination method of water gushing source in Liujiacun tunnel

柳家村隧洞作为滇中引水工程的重要组成部分,在开挖过程中需穿越高水位富水地层,因而容易发生突涌水事故。隧址区地处红层,地下水作为当地居民生产生活的重要水源,因此揭示研究区地下水水化学特征,构建涌水判别模型,对于当地地下水资源的开发利用具有重要意义。分别从3个不同含水层中采集了11组地下水水样以及2个施工支洞的2组涌水水样,运用Piper三线图、离子比例系数、水化学指标相关性分析等方法揭示了区域地下水水化学特征;以主成分分析法和Fisher判别法作为基础模型,构建了一种由R型聚类分析、主成分分析、Fisher判别分析三者耦合的涌水水源快速判别模型,该模型可以较好地适用于水样数据较少的地区;此外,利用柳家村隧洞的实际样本数据,对该模型进行了验证,并与主成分分析、Fisher判别分析两者结合的方法进行了对比。结果表明:地下水中离子成分主要来源于地层中的方解石、白云石、石膏、芒硝等矿物的溶解;利用本文提出的涌水水源快速判别模型判别涌水水源的精度相比于主成分分析、Fisher判别分析两者耦合的方法提高了9.1%。

As an important part of the water diversion project in central Yunnan,Liujiacun tunnel needs to pass through the high-water level water-rich stratum during the excavation process,so it is prone to water inrush accidents.The tunnel site is located in the red layer,and the groundwater is an important water source for production and life of local residents.It is of great significance for the development and utilization of local groundwater resources to reveal the hydrochemical characteristics of groundwater in the study area and establish a water gushing discrimination model.This article collected 11 sets of groundwater hydrochemical samples from three different aquifers and 2 sets of inflow water samples from two construction adits,and revealed the hydrochemical characteristics of regional groundwater by using the methods such as piper trilinear nomograph,ion proportion coefficient and correlation analysis of hydrochemical indexes.Taking principal component analysis and Fisher discriminant analysis as the basic model,a fast discriminative model of water inflow source coupled by R-type clustering,principal component analysis and Fisher discriminant analysis was constructed.The model is suitable for areas with less water sample data;in addition,the actual sample data of Liujiacun tunnel were used to verify the model,and compared with the method combining principal component analysis and Fisher discrimination.The results show that the ionic components in groundwater mainly come from the dissolution of calcite,dolomite,gypsum,glauberite and other minerals in the formation.Compared with the coupling method of principal component analysis and Fisher discriminant analysis,the accuracy of using the fast discrimination model in this paper is 9.1%hig-her than that of the coupling method of principal component analysis and Fisher discriminant analysis.