Landslide Reliability Analysis Based on Transfer Coefficient Method: A Case Study from Three Gorges Reservoir

To evaluate the reliability of a landslide in a reservoir, the universal transfer coefficient method, which is popularized by the Chinese standard, is adopted as performance function in this study for： （1） common deterministic method stability evaluation; （2） reliability evaluation based on a Monte Carlo method; （3） comparison of landslide reliability under different water levels and under different correlation coefficients between soil shear strength parameters （c, Φ）, respectively with mean, standard deviation, reliability coefficient and failure probability. This article uses the Bazimen （八字门） landslide, which is located at the outlet of Xiangxi （香溪） River in the Three Gorges Reservoir, as an example to evaluate its stability and reliability under different water levels with two-dimensional deterministic and probabilistic methods. With the assumption that constant mean and normal distributed shear strength parameters （c, Φ）, correlation coefficient c, Φ=-1 based reliability analysis, compared with c, Φ=0 and 1, indicates obviously more increase of reliability index and lower standard deviation as water levels rise. To the case of a certain water level, c, Φ=-1 does not have constantly positive or negative effects on landslide reliability compared with c, Φ=0 or 1, but is associated with water level. Whereas the safety factor Fs by deterministic method, which is almost the same value as corresponding mean of safety factor from probabilistic analysis, will increase slightly as water level increases.

Research on Reservoir Landslide Thrust Based on Improved Morgenstern-Price Method

The curve of landslide thrust plays a key role in landslide design.The commonly used transfer coefficient method(TCM)and Morgenstern-Price method(MPM)are analyzed.TCM does not take into account the moment balance between slices.Although MPM considers the moment balance,the calculation is complex,and it does not consider that the force between slices may be less than zero at the back edge of the landslide.The rationality and feasibility of the improved MPM are verified by calculating the landslide stability coefficient and landslide thrust at different reservoir water levels.This paper studies the law of landslide thrust when the reservoir water level changes,and discusses the determination of design thrust,to provide a certain theoretical basis for the design of reservoir landslides.

Landslide stability for Shuitianba in the Three Gorges area

According to the data of preliminary survey, the authors established a landslide geological model,on the basis of analyses on the sensitivity of landslide, tried to simulate and calculate the landslide stability of Shuitianba with the method of transfer coefficient when it is under different strength parameters, and study the landslide mechanism. The results show that it is sensitive to the effects of shear strength parameters of sliding zone and groundwater level on landslide stability safety coefficient, which provides reliable basis for calculation of landslide stability.