应力对裂隙岩体等效渗透系数影响的离散元分析

DISCRETE ELEMENT ANALYSIS OF EFFECT OF STRESS ON EQUIVALENT PERMEABILITY OF FRACTURED ROCKMASS

基于现场调查的裂隙网络信息及裂隙网络模拟技术——Monte-Carlo法,采用UDEC中的Fish语言编制裂隙岩体计算模型生成程序DFN-GEN。此程序解决由于裂隙繁多而引起的网格离散困难的问题,可生成大量随机节理,直接进行网络离散,生成裂隙岩体计算模型(DFN),最终用于水力耦合数值计算。结合DECOVALEX国际合作项目TASK C子课题,利用DFN-GEN程序生成裂隙岩体计算模型,研究裂隙岩体水力学特性,探讨应力对裂隙岩体等效渗透系数的影响规律,为研究核废料处置库、坝基、边坡等裂隙岩体工程实践提供方法。

Based on the joint information from in-situ survey and numerical simulation technique of joint（Monte-Carlo method）,the Fish language in UDEC is adopted to compile a program to generate the calculation model of fractured rockmass named DFN-GEN.DFN-GEN program can solve the problem of discrete mesh caused by the various joints.With this program,lots of random joints are generated;the fractured rockmass is meshed directly and the calculation model of fractured rockmass is generated which is finally used in the hydro-mechanical（HM） coupling calculation.DFN-GEN program is adopted to generate the calculation model of fractured rockmass and to study the hydro-mechanical coupling behavior of rockmass.Combining with TASK C of the international cooperation project DECOVALEX,the discrete fracture network（DFN） is generated and the HM behavior of fractured rockmass is studied.The effect of stress on equivalent permeability of rockmass is also analyzed.A basis is provided for engineering practice of fractured rockmass such as underground disposal of nuclear waste repository,dam foundation,slope stability and so on.