大型地下厂房洞室群围岩开挖松弛效应与渗透性演化特征

发布时间：2018-03-15 11:53

本文选题：开挖松弛效应　切入点：地下厂房　出处：《天津大学学报(自然科学与工程技术版)》2017年06期 　论文类型：期刊论文

【摘要】：锦屏一级水电站地下厂房洞室群开挖规模巨大,赋存于极高至高地应力和低强度岩体环境下,且受f13、f14、f18断层切割,其围岩稳定性将成为影响工程安全和正常运行的重要因素之一.结合现场声波监测资料,采用裂隙岩体等效弹塑性本构模型以及基于Hoek-Brown参数的偏应力破坏准则对开挖松弛区进行模拟与评价.此外,重点关注洞室群围岩在地下厂房开挖过程中渗透特性的演化,并采用SVA方法对其防渗排水措施的渗控效应进行分析与评价.研究结果表明:采用塑性屈服区以及偏应力破坏准则表征围岩开挖松弛效应是合理的,高地应力、低强度应力比是造成锦屏一级地下厂房围岩开挖松弛区较大的主要原因;洞室群围岩在地下厂房开挖过程中渗透特性可增大3个数量级,影响范围达35m;围岩渗透特性演化对渗流场具有显著影响,影响程度取决于与洞室群的距离以及防渗排水措施的渗控效应.
[Abstract]:The excavation scale of underground powerhouse group of Jinping I Hydropower Station is huge, which occurs in the environment of extremely high to high ground stress and low strength rock mass, and is cut by f13f14f18 fault. The stability of surrounding rock will be one of the important factors that affect the safety and normal operation of engineering. The equivalent elastoplastic constitutive model of fissured rock mass and the criterion of deflection stress failure based on Hoek-Brown parameters are used to simulate and evaluate the relaxation zone of excavation. In addition, the evolution of seepage characteristics of surrounding rock mass in underground powerhouse during excavation is emphasized. The SVA method is used to analyze and evaluate the seepage control effect of seepage prevention and drainage measures. The results show that it is reasonable to use plastic yield zone and stress failure criterion to characterize the relaxation effect of surrounding rock excavation. The low strength stress ratio is the main reason for the large relaxation zone of surrounding rock excavation of the first class underground powerhouse in Jinping, and the permeability characteristics of surrounding rock of cavernous group can be increased by 3 orders of magnitude during the excavation of underground powerhouse. The influence range is 35 m.The evolution of surrounding rock permeability characteristics has a significant influence on the seepage field, and the influence degree depends on the distance from the cavern group and the seepage control effect of seepage prevention and drainage measures.
【作者单位】：武汉大学水资源与水电工程科学国家重点实验室;长江勘测规划设计研究院;长江水利委员会长江科学院;
【基金】：国家重点基础研究发展计划(973计划)资助项目(2011CB013503) 国家自然科学基金资助项目(51609019)~~
【分类号】：TV554;TV731.6

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