Abstract Stabilizing piles are widely used for reinforcing landslides in the Three Gorges Reservoir area, China. Due to reservoir operations, long-term water-level fluctuations (WLFs) may cause instability or failure of the reservoir landslide and piles system (RLPS). This study experimentally investigated the deformation characteristics and mechanisms of the RLPS under long-term WLFs. The results showed that long-term WLFs led to loading and unloading cycles and consequently a weakening of the slope stability, where retrogressive failure and system instability were observed. Retrogressive failure at the slope toe was caused by topographical variation and physical and mechanical deterioration, which may be a result of the long-term WLFs. System instability was accompanied by a stress-release process above the new slip surface and was determined to be dependent on the geological structure of the RLPS. Based on this investigation, the evolution model of the pile-reinforced landslide under long-term WLFs was proposed. Even though the RLPS was adversely affected by the long-term WLFs, it maintained a relatively steady state due to the reinforcement of the piles. Effective pile installation changed the development of the reservoir landslides and prevented the entire slip surface from reaching a critical state. Thus, a catastrophic consequence was avoided, except for the local failure. Through physical modeling, this study experimentally provided a deeper understanding of the deformation mechanisms and evolution of the RLPS influenced by the long-term WLFs.

中文翻译：

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长期水库运行下桩基滑坡变形机制及演化

摘要 我国三峡水库地区广泛采用稳定桩加固滑坡。由于水库运行，长期的水位波动（WLF）可能导致水库滑坡和桩系统（RLPS）的不稳定或失效。本研究通过实验研究了长期 WLF 下 RLPS 的变形特征和机制。结果表明，长期 WLF 导致加载和卸载循环，从而削弱边坡稳定性，观察到倒退破坏和系统不稳定。坡脚处的倒退破坏是由地形变化和物理和机械恶化引起的，这可能是长期 WLF 的结果。系统不稳定伴随着新滑动面上方的应力释放过程，并被确定取决于 RLPS 的地质结构。在此基础上，提出了长期WLFs下桩基滑坡的演化模型。尽管 RLPS 受到长期 WLF 的不利影响，但由于桩的加固，它保持了相对稳定的状态。有效的桩基安装改变了水库滑坡的发展，防止了整个滑坡面达到临界状态。因此，除了局部故障之外，避免了灾难性后果。通过物理建模，本研究在实验上提供了对长期 WLF 影响的 RLPS 变形机制和演化的更深入理解。