Permeability of the reservoir water fluctuation zone of landslide bodies in the Three Gorges Reservoir Area, China

The fluctuation of water level in the Three Gorges Reservoir is up to 30 m, and the reservoir water fluctuation zone is the important channel of reservoir water flowing in and out of a landslide. The permeability characteristics and parameters of the reservoir water fluctuation zone of landslide bodies are of great significance for calculating the seepage of the reservoir landslide and evaluating the stability of the landslide. In this paper, 396 landslides in the Three Gorges Reservoir Area were studied, and 1188 test pits were sampled. In an analysis based on test data, the classification indicators of landslides can be divided into two types: provenance lithology and compositional structure. According to provenance lithology, the landslides can be divided into dolomite and limestone, marl, sandstone and mudstone inlaid rocks, siltstone, and argillaceous limestone. In addition, according to the compositional structure, landslide bodies can be divided into fine-grained soil, soil containing gravel stone, soil clip gravel stone, crushed rock soil, and fractured rock mass, where there are three types and five sub-categories. Based on this study, we found that the permeability of the landslide bodies has regional distribution characteristics, which is positively correlated with gravel content and provenance lithology strength and is mainly medium and better.