Abstract: The saturated loose deposits formed by engineering waste and earthquake landslide deposits under rainfall conditions have strong mobility, their movement speeds are fast, and the damage scopes are larger than expected. Their internal mechanisms have always been a hot research issue in international academic circles. In this paper, the saturated deposit shear dilatancy model constructed by Iverson based on the limit state soil mechanics principle is integrated into the physical model of the Savage-Hutter slide motion physical model. The finite volume method is used to solve the landslide kinetic equations and achieve full simulation of the motion evolution of the saturated loose accumulation body. Finally, a back in-situ analysis of the catastrophic construction solid waste landslide that occurred in Shenzhen in December 2015 is presented and evolution process of the landslide is reproduced. The results show that the dilatancy effect is the main reason for rapid movement of the saturated loose accumulation bodies and the initial state (void ratio or volume fraction of solid phase) of the saturated loose deposit has a crucial influence on its motion-accumulation evolution process.

Key words: saturated loose accumulation body, dilatancy, mobility, physics model, computation simulation