引大济岷工程渠首高陡边坡稳定性研究

Stability study of high steep slopes at the head section of the Water Diversion Project from Dadu River to Minjiang River

摘要

针对位于青藏高原东缘横断山脉地区的引大济岷工程渠首高陡边坡稳定性问题，采用合成孔径雷达干涉测量技术开展长时间序列的地表变形监测并识别潜在失稳区域，同时利用无人机倾斜摄影技术获取边坡高精度三维地形数据，进而结合极限平衡法和有限元强度折减法开展潜在不利工况下的边坡稳定性计算分析。研究结果表明，SBAS-InSAR计算捕捉的持续表面变形与卸荷岩体局部松动垮塌空间对应，现状条件下的边坡稳定性良好；地震和降雨作用将显著降低边坡安全系数并可能诱发中浅层的整体滑动，但由于研究区岩土体物理力学性质较好，边坡仍将在极端工况下保持稳定状态。本研究星载雷达地表变形观测与数值模拟计算相结合的分析方法可为类似水利水电工程高陡边坡的稳定性评价提供有益的借鉴与参考。

Abstract

Aiming at the stability issues of high steep slopes at the initial section of the Water Diversion Project from Dadu River to Minjiang River(Yindajimin Project) located on the eastern edge of the Qinghai-Xizang Plateau in the Hengduan Mountains area, long-term series of ground deformation monitoring using Synthetic Aperture Radar Interferometry(InSAR) technology were employed to identify potential instability areas. High-resolution three-dimensional terrain data of the slopes were also acquired using Unmanned Aerial Vehicle(UAV) photogrammetry. Stability analyses under potentially adverse conditions were then conducted combining Limit Equilibrium Method and Finite Element Strength Reduction. The results demonstrate that the continuous surface deformations captured by SBAS-InSAR correlate spatially with local collapse of loose rock masses, indicating good stability of the slopes under current conditions. However, earthquake and rainfall activities significantly reduce the safety factor and may induce shallow overall sliding. Nevertheless, due to the favorable physico-mechanical properties of the rock materials in the study area, the slopes are expected to remain stable even under extreme conditions. The combined approach of satellite radar observation and numerical simulation provides a valuable reference for the stability assessment of similar high steep slopes in other hydroelectric engineering projects.

关键词

引大济岷工程 / 高陡边坡 / 稳定性分析 / 合成孔径雷达 / 极限平衡法 / 强度折减法

Key words

Yindajimin Project / High Steep Slopes / Stability Analysis / Synthetic Aperture Radar / Limit Equilibrium Method / Strength Reduction Method

Author summay

朱少帅(1989—), 男, 工程师, 硕士, 主要从事岩土体稳定性相关的生产和研究工作。E-mail: [e-mail]