哈达山水利枢纽右岸三维渗流场特性研究

3D seepage flow field characteristics research for the right bank of Hadashan Hydroproject

坝基渗漏及渗透稳定问题是哈达山水利枢纽工程遇到的主要地质问题,将影响水库工程效益的发挥和大坝的安全运行,需采取适当的渗控工程措施.根据工程地质条件,建立了能够反映其主要工程地质构造和坝基面几何形状的三维有限元模型,并采用固定网格的截止负压法增量迭代技术求解渗流场.考虑正常、设计和校核3种工况,研究土坝和右坝肩的绕坝渗流场特性,分析浸润面、地下水位分布、渗透坡降和渗透稳定性,估算渗流量.对防渗墙及基岩渗透参数进行敏感性研究,分析其对渗流场的影响.结果表明,设置防渗墙能有效降低墙后坝肩和坝体的浸润面,且坝体各部位的最大渗透坡降均满足渗透稳定性要求.

The geological problems of the building of Hadashan Hydro-project are the seepage of the dam base and its stability of infiltration,which will influence the engineering benefit and the safe operation of the dam,and thus proper measures are needed to control the infiltration.A 3D finite element model of seepage flow is set up,which can simulate the geologic conditions of the structure and the geometrical boundary of the dam foundation based on the technology of fix meshing iteration with the cut-off negative pressure method for solving filtration problems.And normal,design and verification conditions are considered to study seepage field characteristics of the earth and by-pass right abutment.Seepage faces,distribution of ground water level,seepage gradient and seepage stability are analyzed.Sensitivity analysis on the percolation parameter of the cutoff wall and rock base has been done in this paper;and their influence on seepage area is deeply analyzed.The results show that the cutoff wall can reduce seepage face of the abutment and dam,and each part of the dam for the largest seepage gradient can satisfy seepage stability.