Model Test and Numerical Analysis on the Deformation and Stability of a Landslide Subjected to Reservoir Filling

Abstract

Reservoir filling can affect the landslide stability and cause the landslide deformation within the reservoir area. In this paper, a physical model test and a series of numerical analyses were combined to investigate the landslide deformation and stability under reservoir filling. The surface deformation, deep displacement, and pore water pressure were recorded during the physical model test. In the model test, the increasing period of the pore water pressure inside the landslide is proposed to be a critical period for the landslide subjected to the reservoir filling. During this period, large landslide deformation occurred. The numerical analyses show that a greater factor of safety (FOS) appeared under a higher water level rising rate or a lower permeability coefficient during the water level rising stage when other variables are fixed, due to the domination of the reservoir buttressing effect which can increase the landslide resistance. During the reservoir maintaining stage, the reservoir water infiltrated into the landslide continuously to cause the matric suction dissipation and pore water pressure increase, which reduced the landslide shear strength and then decreased the landslide stability.

Seepage, Deformation, and Stability Analysis of Sandy and Clay Slopes with Different Permeability Anisotropy Characteristics Affected by Reservoir Water Level Fluctuations

“…Luo et al [15] conducted a model test of the failure process of a soil slope with different angles under the drawdown of the water level and found that the position of the slide surface became deeper with the increase of the slope angles. Hu et al [16] carried out laboratory model tests of the deformation mechanism of landslides under water level fluctuations and concluded that the increase of pore water pressure inside the slope soil was the key factor triggering the slope failure. Yang et al [17] studied the failure process of a silt slope under the sudden drop of reservoir water level and found that failure mode and crack propagation were closely related to the mechanical properties of unsaturated soil.…”

Stability Analysis of Rock Slope Based on Improved Principal Component Analysis Model: Taking Fuwushan Slope as an Example

“…PCA is used to process the original data, and the six influence factors are reduced into four main influence factors, which reduce the complexity of the algorithm; RVM is applied to establish the mapping relationship between influence factors and slope stability after dimension reduction, so as to predict slope stability. The PCA-RVM model simplifies the complex problems and makes the prediction process more efficient and concise (2) The results show that the PCA-RVM model is superior to the GEP model and the RVM model in terms of mean square error and mean relative error in predicting rock slope stability, with higher accuracy and lower discreteness. In the aspect of slope stability, the PCA-RVM model has high credibility, and the predicted value is basically consistent with the actual value, which can provide reference for the prevention and control of slope disasters…”

“…Slope sliding is a common geological disaster phenomenon, which has great harm. Once it occurs, it will seriously threaten people's lives and property and various engineering safety, causing great losses [1,2]. Some slope instability disasters, which are located in China, are shown in Figure1.…”

Impact of Water Level Fluctuations on Landslide Deformation at Longyangxia Reservoir, Qinghai Province, China

“…Within a relatively short period, the sand structure is irreversibly deformed due to the loading and unloading of water, and the structure is rearranged. With the increase in the pore water pressure, matrix suction is reduced, and the effective stress on the sand framework decreases, which reduces the shear strength and stability of the landslide [67,68]. However, a rise in water level generates water pressure, which provides a supporting force acting on the landslide surface, in turn increasing its resistance to movement and increasing the stability of the slopes [66][67][68][69][70].…”