Abstract:Abstract：Luojiaping landside locates in 38km upstream of the dam site of Xiangjiaba Hydropower Station and there is no deformation before water storage of xiangjiaba dam. However

obvious deformation has been found after phase-i water storage and the velocity of deformation has increased after phase-ii water storage. It is shown that a landside caused by water storage has occurred there. Detailed geological structural investigation

which based on the analysis of the monitoring data of water storage

rainfall conditions and deformation

are carried out in this paper in order to research the relationship between the curve of displacement-depth and geological characteristic. The confined water model of bedding rock landslide is put forward to explain deformation behavior. The research shows the water storage is the cause of landside

the rainfall is the motivation of landside. The groundwater level is rising during water storage

but parts of the sliding surface and soil deposits at the toe of landslide under the groundwater level caused the latter becoming soft. The resistance force then decreased due to plastic deformation and viscous. The compatibility of deformation of dangerous rock body may occur by plastic deformation. The ground cracking after landside. The confined water turns out during the rainfall and water impoundment

the heavier the rainfall the higher the pressure head will be

and the pressure is concerned at the lower part of landside. As a result of confined water and its own weight

the deformation rate and deformation size of the toe area is larger than the heel area. The landside is more dangerous in persistent rain than heavy rains.