岩溶隧道对地下水环境影响分析及涌水量预测研究

Analysis of the Impact of Karst Tunnels on Groundwater Environment and Prediction of Water Inflow

在隧道的建设过程中,尤其是在岩溶地区,很多隧道均遭遇了地下水灾害,研究岩溶地下水系统在隧道工程干扰下的行为是十分必要的。以重庆主城区拟建的鹿角隧道为例,分析其隧址区内水文地质条件,并建立隧址区地下水渗流模型;在此基础上,模拟隧道工程对地下水环境的影响;并采用地下水径流模数法、数值模拟法对隧道进行最大涌水量预测。结果表明:隧道施工期,地下水影响范围随时间增加而变大,开挖两年后达到最大,地下水位在隧道运营十年后趋于稳定,但难以恢复到天然状态;隧道高程越低,隧道水力传导系数越大,对地下水环境影响越大。研究结果明确了突水风险段,对隧道施工安全及设计决策提供理论及技术支撑,为运营期环境治理提供可靠判据。

During the construction process of tunnels,especially in karst areas,many tunnels have encountered groundwater disasters.So it is necessary to study the behavior of karst groundwater systems under tunnel engineering interference.Taking the proposed Lujiao Tunnel in the main urban area of Chongqing as an example,this paper analyzes the hydrogeological conditions in the tunnel site area and establishes a groundwater seepage model in the tunnel site area.On this basis,the study simulates the impact of tunnel engineering on the groundwater environment.And the groundwater runoff modulus method and numerical simulation method are used to predict the maximum water inflow of the tunnel.The results show that during the tunnel construction period,the range of groundwater impact increases with time,reaching its maximum after two years of excavation.The groundwater level tends to stabilize after ten years of tunnel operation,but it is difficult to restore to its natural state;the lower the tunnel elevation,the greater the hydraulic conductivity coefficient of the tunnel,and the greater the impact on the groundwater environment.Then the risk section of water inrush has been clarified,providing theoretical and technical support for tunnel construction safety and design decision-making,and providing reliable criteria for environmental management during the operation period.