The mechanical behavior of a particle assembly is described based on Cundall's distinct element method which uses an explicit numerical scheme. Particle interaction was detected at every contact, and particle motion modelled for each particle in an assembly.
We used Cundall's simulation method to study the mechanism of slope collapse. Based on results obtained from numerical tests, we conclude that, 1) The shape of the sliding section is wave like, and 2) Particle rotation has a major function in determining the sliding zone of a section.