基于三维非稳定渗流分析的隧洞开挖地下水环境影响评价

发布时间：2019-04-20 16:23

【摘要】：水利工程中隧洞施工通常采用全部开挖完成再衬砌的方法。如针对开挖施工的短暂状态采用稳定渗流计算分析其对地下水环境的影响,并不符合实际,且往往会夸大地下水位降落的幅度和影响范围,因此采用非稳定渗流数值模拟技术来评价将更为合理。以某水电站发电引水隧洞施工为例,采用饱和-非饱和非稳定渗流理论,建立了引水隧洞区域的三维有限元模型,对隧洞开挖过程中区域地下水非稳定渗流场进行了数值模拟,总结分析了隧洞从开始挖掘到贯通过程的地下水变化规律并进行地下水环境影响评价。结果表明:采用三维非稳定渗流分析预测隧洞开挖过程中地下水位降落和降落漏斗扩大的过程是可行的;该工程引水隧洞开挖对该区域地下水影响较小,地下水补排关系总体无变化。
[Abstract]:In hydraulic engineering, the method of complete excavation and re-lining is usually adopted in tunnel construction. If the steady seepage calculation is used to analyze the influence on the groundwater environment in the short-term state of excavation, it does not accord with the reality, and it often exaggerates the amplitude and influence range of the groundwater level fall. Therefore, it is more reasonable to use unsteady seepage numerical simulation technology to evaluate. Taking the construction of the diversion tunnel of a hydropower station as an example, a three-dimensional finite element model of the diversion tunnel area is established by using the saturated-unsaturated unsteady seepage theory, and the numerical simulation of the unsteady seepage field of the regional groundwater during the excavation of the tunnel is carried out. This paper summarizes and analyzes the variation rule of groundwater in the process of tunnel excavation and penetration, and evaluates the environmental impact of groundwater. The results show that it is feasible to use three-dimensional unsteady seepage analysis to predict the process of underground water level falling and falling funnel expanding during tunnel excavation. The excavation of diversion tunnel in this project has little influence on groundwater in this area, and the relationship between groundwater recharge and discharge has no change in the whole.
【作者单位】：河海大学水文水资源与水利工程科学国家重点实验室;河海大学水利水电学院;宜春市水利局;
【基金】：江苏高校优势学科建设工程资助项目(水利工程) 江苏省自然科学基金青年基金项目(BK2012410) 中央高校基本业务费项目(2014B11914)~~
【分类号】：TV554

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