华蓥山隧道隧址区水文地球化学特征及涌水来源识别

Hydrogeochemical characteristics and identification of water source in Huayingshan Tunnel District

针对华蓥山隧道施工中可能存在的涌突水问题,本研究在现场水文地质调查,取样测试分析的基础上,对华蓥山隧道隧址区地表水、地下水和隧道涌水的水文地球化学特征进行了分析,并对隧道涌水水源进行了识别。结果表明:隧址区水体的水化学类型主要为HCO_3-Ca和HCO_3·SO_4-Ca型,水质偏弱碱性,水化学成分主要来源于岩石的风化作用;隧址区浅层地下水和地表水联系紧密,大气降水是各水体的主要补给来源;隧址区地下水补给高程为315~1467 m,在东南区域,隧道涌水主要来自三叠系上统须家河组(T_3xj)碎屑含水层和侏罗系中统新田沟组(J_2x)碎屑岩含水层,西北部主要来自三叠系下统嘉陵江组(T_1j)灰岩岩溶含水层。

In order to predict the potential water inrush problem produced during the construction of Huayingshan tunnel,the research analyzed the hydrogeochemical characteristics of the surface water,groundwater and inrush water of Huayingshan tunnel,and identified the inrush water resource based on the field investigations and hydrochemical analysis of water samples. The result shows that,in Huayingshan tunnel area the main hydrochemical types of regional water are HCO_3-Ca and HCO_3·SO_4-Ca.The water quality is in alkalescency,and the hydrochemical origin of water is rock weathering. There is close relationship between shallow groundwater and surface water. Precipitation is main supply sources of all kinds of water. Replenishment elevation of study area is 315 ~ 1467 m. In the southeast region the tunnel inrush water mainly comes from sandstone aquifers of upper Triassic Xujiahe formation（T_3 xj） and middle Jurassic Xintiangou formation（ J_2x）,and the northwest comes from limestone karst aquifer of lower Triassic Jialingjiang formation（ J_1x）.