In order to reveal the mechanism of disintegration deformation and failure of debris landslide under rainfall

connected with the engineering concrete example of medium and deep debris landslide

through the collection

arrangement and analysis of related data

the site investigation and exploration of engineering geology

indoor and outdoor physico-mechanical test

adopting the analytic means of mathematic statistics

unbalanced-thrust method and three-dimensional contact elastoplastic FEM together

and the theory of groundwater pipe network drainage system(GPNDS)

its stability and process of the deformation

disintegration and failure under rainfall were analyzed

which the main disintegration deformation and failure mechanism and general mechanics mechanism of medium and deep debris landslide under rainfall are revealed. The research result shows as follows: First

long time proper strength steady rain or intensive rainfall is the main factor of its instability and failure. Second

adopting contact elastoplastic FEM thinking over the action of rainfall may better reflect the actual locating state and sliding process of debris landslide under rainfall; and it may afford one method that can be used as a reference of stability analysis

accurate evaluation and forecast of the debris landslide.