Abstract:Qinggangping landslide is a giant ancient landslide. It is located on the right bank of Jinsha River in XiLuoDu Reservoir Area, about 15.5 km away from the dam site. It was affected by the lifting and lowering of reservoir water, and the landslide was partially revived on April 24, 2014. Due to the influence of the reservoir water, the landslide was partially resurrected on April 24, 2014, and the volume of the resurrected body was approximately 3 million m3, the disaster destroyed 137 houses and 0.6 kilometers of rural roads, causing direct economic losses of about 5 million yuan. In view of the huge volume of Qinggangping landslide deposits, the deposits may be revived under the effect of reservoir water lifting in the later period, which will pose a great threat to the lives and property of local residents. Therefore, It is urgent to study the deformation evolution of this landslide. It can provide reference for prevention and treatment of similar disasters. In order to analyze the influence of reservoir water on landslide deposits, this paper based on the on-site double-ring penetration test and dry-wet cycle test of broiled soil on landslide accumulation, using FLAC3D(Fast Lagrangian Analysis of Continua) to simulate the deformation of Qinggangping landslide deposit under the water level lifting and lowering of reservoir area. The evolutionary trend shows that: (1)The average permeability coefficient of the surface layer of the Qinggangping landslide is 6.94×10-2cm/s, which is a medium-strong permeable medium. (2)There is a certain relationship between the soil shear strength index and the number of dry and wet cycles n: cohesion , internal friction angle . (3)When the reservoir water level is stable at 540 m and 600 m elevation, the slope body is stable overall. With the increase of the number of dry and wet cycles, the deformation crack of the slope body gradually increases, and the stability coefficient decreases continuously. When the number of cycles reaches 35 times. The 780~930 m elevation range above the landslide body and the upper part of the giant block stone will slide, and the Qinggangping landslide will be revived again.