复杂裂隙岩体天然渗流场反演分析

Back analysis of natural seepage field in complicated fractured rock mass

水电工程地形地质条件复杂,岩体中常发育有多组节理裂隙,由此造成岩体渗透特性在空间上呈现明显的分区、分带和各向异性的特征。基于大岗山水电站厂房和坝址区地形地质条件和岩体五组主要节理裂隙发育特性,建立三维有限元计算模型,采用二次规划反演法、裂隙岩体渗透张量分析法和自由面计算固定网格法进行分析,利用计算水位与钻孔实测水位的对比,反演出厂房和坝址区天然渗流场,确定了渗透参数和边界条件,为其他工况渗流场分析计算和渗控措施优化提供了基础参数和依据。

Topographic and geologic conditions of hydropower engineering are often complicated,and rock mass is featured by various kinds of joints and fissures,so its permeability is zonal and anisotropic.A 3D finite element model is developed for such complicated rock mass conditions at the Dagangshan hydropower station and its seepage field is studied with this model in combination with a quadratic programming method,permeability tensor analysis method and free-surface-fixed meshing method.Back analysis based on comparison of the calculated and observed water levels is used to calculate the natural seepage field and determine its boundary conditions and seepage parameters.This work provides a basis for analysis of other operating conditions and optimal seepage control schemes.