STUDY ON STABILITY MECHANISM OF BEDDING ROCK LANDSLIDE UNDER PERIODIC RESERVOIR WATER AND RAINFALL COUPLING

In order to explore the stability mechanism of landslide in the Three Gorges Reservoir area under the influence of reservoir water level fluctuation and rainfall coupling factors, the Jiuxianping landslide in Yunyang, Chongqing was taken as the research object. Based on the Global Navigation Satellite Sys-tem(GNSS) monitoring data of Jiuxianping landslide from July 2016 to July 2017, different working conditions were set in the order of periodic time. The Geostudio software was used to explore the stability mechanism of landslide under reservoir water level, rainfall and their coupling conditions. The results show that the decline of reservoir water level is the main cause to control the displacement and deformation of bedding landslide, and the stability coefficient is the lowest 1.206 when the water level decreases from 160m to 145m; during the drawdown period of reservoir water level and 145m stable reservoir water level, heavy rainfall further induced the displacement deformation of landslide, and the stability coefficient decreased to 1.159 at the rainfall intensity of 150mmd-1. In the reservoir water level rise period and (middle) high water level stable period, high speed and heavy rainfall will not have a significant impact on landslide displacement deformation. This paper can provide guidance for the analysis of the formation mechanism of water-related landslides, early landslide monitoring warning criteria and prevention research in the Three Gorges Reservoir.