两河口水电站近坝库岸倾倒变形体失稳运动过程及涌浪研究

Study on the instability process and surge waves of the near-dam bank collapse body in the Lianghekou Hydropower Station

摘要

两河口水电站近坝库岸的托达西倾倒变形体近期变形显著，且变形程度持续加剧。为了评估其失稳破坏对水库及坝区沿线居民的生命安全、财产和基础设施构成的威胁，以两河口近坝库岸托达西倾倒变形体为研究对象，采用有限元-光滑粒子流体动力学(FEM-SPH)耦合方法，系统分析了滑坡的失稳运动过程及滑坡涌浪现象。数值模拟结果表明，托达西倾倒变形体的失稳运动过程持续约30 s,最大运动速度可达25 m/s,滑坡引发的最大位移为1 827 m;滑坡造成的初始最大涌浪高度为28.9 m,涌浪传播至大坝处的最大高度为0.61 m。研究表明，FEM-SPH耦合法在捕捉滑坡体复杂动力学行为及滑坡涌浪方面具有较高的准确性，滑坡失稳过程可分为启动、高速滑动和碰撞停积三个阶段。基于研究结果的大坝风险评估显示，在正常蓄水位下，涌浪传播至大坝的最大高度未超过大坝高程，具备较高的安全裕度。本研究成果为类似水库滑坡及潜在滑坡诱发涌浪的预警与预防提供了重要的参考依据。

Abstract

The recent deformation of the Tuodaxi dumping deformation body on the near-dam bank of Lianghekou Hydropower Station is significant and continues to increase. In order to assess the threat posed by its destabilisation damage to the life safety, properties and infrastructures of the reservoir and the residents along the dam area, systematical analysis was carried out on the destabilisation movement process of the landslide and the landslide surge phenomenon by using the coupled Finite Element-Smooth Particle Hydrodynamics(FEM-SPH) method with the Tuodaxi dump deformer on the near-dam bank of the Lianghekou Hydropower Station as a research object. Numerical simulation result show that the instability process of the Tuodaxi collapse body lasts approximately 30 seconds, with a maximum movement speed of 25 m/s and a maximum displacement of 1 827 m. The landslide-induced initial surge wave reaches a maximum height of 28.9 m, and the maximum wave height at the dam site is 0.61 m. The study demonstrates that the FEM-SPH coupling method accurately captures the complex dynamic behavior of landslides and surge waves. The landslide instability process can be divided into three stages: initiation, high-speed sliding, and impact-deposition. Based on the study result, the dam risk assessment indicates that, under normal water levels, the maximum wave height propagating to the dam does not exceed the dam′s elevation, ensuring a high safety margin. The findings of this study provide valuable references for early warning and prevention of similar reservoir landslides and potential landslide-induced surge waves.

关键词

两河口水电站 / 托达西倾倒变形体 / FEM-SPH法 / 失稳运动过程 / 滑坡涌浪

Key words

Lianghekou Hydropower Station / Tuodaxi collapse body / FEM-SPH method / instability process / landslide-induced surge wave

基金资助

国家自然科学基金项目(42077253)