三峡库区正常运行期间水位将历经周期性涨落起伏,库水位升降速率对库岸边坡稳定性有重要影响。以库区巫山塔坪滑坡为原型,基于透明土试验技术,设计了透明土库岸边坡模型试验系统,包括透明土滑坡模型箱、库水位升降系统以及计算机图像采集系统三部分,进行了不同水位升降速率的模型试验,利用粒子图像测试技术得到透明土滑坡全断面全过程的变形数据,分析了库岸滑坡在不同水位升降速率下的变形特征和演化规律。结果表明：库水位上升滑坡变形由前向后发展,而库水位下降滑坡变形由后向前推进,且库水位下降引起的滑坡体变形更大。库水位升降速率增大,滑坡内部的动水压力效应和地下水位滞后效果越明显,滑坡产生的变形增大,变形特征更明显。滑坡地表位移变化曲线呈现台阶状阶跃上升趋势,水平位移增长明显高于竖直位移,库水位升降速率变大会增加库水位不变的间歇期内滑坡位移,表明滑坡稳定性变差。研究成果可为库区滑坡防治提供重要的理论依据。

During normal operation of the Three Gorges Reservoir, the water level will experience periodic fluctuations, and the rate of water level rise and fall has a significant impact on the stability of the reservoir landslides. Considering the Wushan Tapin H1 landslide in the reservoir area as a prototype, a transparent soil model testing system for reservoir landslides has been designed. This system includes a transparent soil landslide model box, a water level fluctuation system, and a computer image acquisition system. The tests were carried out at different rates of water level rise and fall, and the deformation data of the transparent soil landslide were obtained by using the particle image velocimetry technology over the research profile. The deformation characteristics and evolutionary pattern of the landslide were analysed. The results indicate that during water level rise, landslide deformation progresses from the front to the rear, while during water level fall, the deformation progresses from back to front, with greater deformation caused by water level fall. As the rate of water level fluctuation increases, the dynamic water pressure effect within the landslide and the groundwater level lag effect become more pronounced, resulting in increased deformation and more evident deformation characteristics of the landslide. The surface displacement variation curve of the landslide shows a step-like progression, with horizontal displacement increasing significantly more than vertical displacement. An increased rate of water level fluctuation results in greater landslide displacement during intervals when the water level remains unchanged, indicating a decrease in landslide stability.

TU375.4

国家自然科学基金项目, 重庆英才创新创业示范团队项目，中铁二局集团有限公司科研项目，中煤科工重庆设计研究院（集团）有限公司科研项目