摘要：Jinping I hydropower station is one of the most challenging projects in China due to its highest arch dam and complex geological conditions for *** geological investigation into the dam foundation,a few large-scale weak discontinuities are *** rock masses in the left dam foundation are intensively unloaded,approximately to the depth of 150–300 *** serious geological defects lead to a geological asymmetry on the left and right banks,and thus some major diffculties of dam construction are *** this paper,the influences of geological defects on the project are analyzed,followed by the concepts and methods of treatment *** on the analysis,the treatment methods of the weak rock masses and discontinuities are carefully determined,including the concrete cushion,concrete replacement grids,and consolidation *** work together to enhance the strength and integrity of the dam *** and calibrations through geo-mechanical model tests in combination with feld monitoring results in early impoundment period show that the arch dam and its foundation are roughly stable,suggesting that the treatment designs are reasonable and *** proposed treatment methods and concepts in the context can be helpful for similar complex rock projects.

摘要：岩体参数是岩体工程设计与优化的重要依据。以现场精细结构测绘为基础,借助数值计算工具,进行大样本岩体力学试验为岩体参数的确定提供了一种新思路。精细结构描述的重点在于现场地质测绘工作的细致。以统计窗为基础,结合地质素描和数码摄像技术,补充发展了一套岩体精细结构测绘的现场工作方法。以现场测绘为基础,建立岩体结构模型。同时,通过离散元数值试验与物理模型试验的对比,验证数值试验的精度,并以锦屏一级水电站为例对坝区岩体进行大样本岩体数值试验,给出应力–位移全过程曲线、应力分布、位移分布及塑性区分布等分析成果。对比发现,数值试验结果与岩体质量评价结果基本吻合,计算结果可靠。数值试验细化了岩体参数的分布特征,大样本试验将会促进工程参数风险预测和可靠度分析的发展。

摘要：在建的锦屏一级水电站蓄水后坝基(肩)软弱岩体在高水头作用下的弱化效应是工程建设十分关心的问题。为揭示这种弱化效应,提出一套岩体水压弱化效应的试验研究方法:采用岩体形成过程–力学条件模拟,力学参数控制三轴压缩全过程试验的手段制备岩体试件,对岩体试件进行现今天然状态与1~4 MPa静水压力的系列三轴压缩试验(围压为5,10,15,20,25,30 MPa)。试验结果及分析表明,在浅部低应力岩体中弱化效应十分显著,强度参数中的内摩擦因素f的弱化程度在13%以内,c的弱化程度随静水压力的升高而急剧增大,最大可达100%;变形模量的弱化程度在20 MPa围压以下随静水压力的升高而增大,随围压的升高而减小,围压达到20 MPa后则基本无弱化现象。同时,建立了不同静水压力工况下岩体力学参数预测模型。这些成果已在锦屏一级水电站工程建设中得以应用,研究方法为岩体力学性能的试验室研究开辟了新的有效途径。