巴东县城白土坡裂隙岩体等效渗透系数数值分析

Numerical analyses of the equivalent coefficient of permeability of the Baitupo slope in Badong County

对三峡库区巴东县城白土坡岩体的裂隙进行了详细的野外调研与系统测量,根据裂隙网络模拟技术Monte Carlo法,使用VB语言编制了裂隙网络计算模型生成程序,对白土坡岩体的裂隙分布进行网络模拟。将裂隙网络模拟成果导入离散元稳定流渗流分析模块(UDEC),生成裂隙网络数值模型,通过对模型周边设置定水头边界并提取边界上裂隙的流量,然后根据立方定理和Darcy定律对白土坡岩体的等效渗透系数进行了求解分析。数值分析结果表明:巴东县城白土坡裂隙岩体等效渗透特征单元体REVK=20 m×20 m;等效主渗透系数最大值为K1=1.15×10-4m/s,最小主渗透系数为K2=8×10-6m/s;主渗方向与岸坡倾向水平反方向的夹角为-40°左右。

Based on the data obtained from field investigation and measurements,simulation of fracture network distributing in the Baitupo slope was conducted with the Monte Carlo method,which was implemented by using the VB language. The numerical model of the fractured network was generated by importing the simulation of fracture network into the discrete element seepage analysis module,and the flux of fracture on exudation boundary was obtained with the constant head boundary. The analysis of the equivalent coefficient of permeability was conducted based on the cubic law and the Darcy＇s law. The numerical simulation results show that the size of the representative element volume（REVK） of the fractured rock mass of the Baitupo slope is 20 m × 20 m,the maximum principal equivalent coefficient of permeability is 1. 15 × 10^- 4m / s,the minimum principal coefficient of permeability is 8 × 10^- 6m / s and the angle between the direction of the main seepage and the opposite direction of slope inclination is 40°.