Abstract: In the excavation construction of the high and steep slope on the left bank of Yangfanggou hydropower station, the 3D numerical modeling method is used to analyze the deformation characteristics and the stability of slope during excavation. In the process, it is found that the potential deformation or instability area in the upper part of the slope is mainly distributed in the vicinity of the opening line, which results in some risk of local instability after combination of the excavated faults. The excavation mainly changes the stability of rock mass in the area of excavation and its vicinity, while the stability of the rock mass outside the area is not significantly affected. The deformation of middle and upper part of excavated area is mainly the unloading rebound deformation in the vertical direction. The overall deformation value of the slope is relatively low. The calculation and analysis method can be used for reference in the excavation design of similar projects.

Key words: Yangfanggou hydropower station, high and steep slope, excavation deformation, stability, numerical simulation

摘要： 针对杨房沟水电站左岸坝肩高陡边坡开挖施工情况，采用三维数值分析方法，深入开展施工期边坡开挖变形响应特征及稳定性分析评价工作。计算发现：边坡上部开挖潜在变形或失稳区域主要分布于开口线邻近部位，与开挖揭露的断层组合后存在一定的局部失稳风险，开挖主要改变开挖范围及其附近边坡岩体的稳定性，基本不对开挖影响区以外岩体的稳定性造成明显影响；开挖中上部以垂直向的卸荷回弹变形为主，边坡开挖整体变形量值处于相对较低的水平。计算及分析方法对类似高边坡工程的开挖施工设计有一定的借鉴作用。

关键词: 杨房沟水电站, 高陡边坡, 开挖变形, 稳定性, 数值模拟