Genetic types and geological features of large scale and extra-large scale layered landslides in the Three Gorges Reservoir area

The large-scale and extra-large scale landslides in the Three Gorges Reservoir area have a great impact on the rock landslides. The geological conditions in various sections of the reservoir make the landslide genesis patterns different, resulting in different forms of motion after the damage and the degree of disintegration of the rock masses. With 51 typical large scale or extra-large scale bedrock landslide data collected in the Three Gorges Reservoir area, the cause model of the landslide failure is reversed according to the structure of the stacked rock masses and the geological conditions. The landslides with different genetic models have different permeability characteristics and resurrection responses to reservoir water level changes. The results show that from the head to the tail of the reservoir, along with the decreasing of the rock dips, in addition to the distribution of the full-slide type, the genetic types gradually change from collapse type and anti-tilt type to translation type. In the permeability of the slope, the change of rock mass structure caused by the genetic model and the shale content in the slope body result in a large difference in the permeability of the front and rear edges of the bedding landslide. But the anti-dipping landslides are the opposite, and under the influence of reservoir water fluctuations, the permeability of different slopes and the shape of the slip surface jointly determine the difference of resurrection deformation of the landslides.