关键词: 水动力型滑坡;离心模型试验;降雨;库水位变动;失稳机制;

Abstract: Hydrodynamic landslides are the most common type of landslides in high-dam and large-scale reservoir areas in southwest China and are an important factor affecting the safety of reservoir areas.After the water storage operation in the Huangdeng Reservoir area, a series of ancient landslides on the reservoir banks were revived due to the change in hydrodynamic conditions.Taking the Cheyiping landslide in the Huangdeng Reservoir area as the research object, a set of test systems was independently designed, and a large-scale geotechnical centrifuge was used to carry out centrifugal model tests for these large landslides under different schemes to clarify the primary and secondary effects of reservoir water level drop and rainfall in landslide deformation, The deformation and instability mechanism was revealed.The results showed that in the rising stage of the reservoir water level, the growth of pore pressure showed a certain hysteresis; in the stage of reservoir water level decline, the dissipation rate of pore pressure was less than the falling rate of the reservoir water level; in the rainfall stage, for landslides with cracks, the pore pressure increased rapidly.(2) The decline of the reservoir water level is the main factor for the deformation of the Cheyiping landslide, and rainfall is a triggering factor.The drop in the reservoir water level causes the landslide to generate dynamic water pressure pointing to the outside of the slope, resulting in the instability of the landslide and the formation of cracks; the cracks provide a channel for rainfall infiltration and aggravate the development of cracks.(3) It is relatively difficult to control the Cheyiping landslide.It is suggested to relocate the small village of Cheyiping and prepare an emergency plan at the same time.

Key words: hydrodynamic landslide; centrifugal model test; rainfall; reservoir water level fluctuation; instability mechanism;