Abstract
The estimation of risk due to rockfall is often done empirically. Rockfall simulation helps to describe the motion of rockfall on a slope. This paper details a typical simulation method and analysis of the manner of rockfall. Fundamental idea is concretely shown to consider the roughness of the slope surface to reproduce the state that is close to the real slope. A treatment method of the roughness at the moment of the collision between a rockfall and a slope was developed. The method expressed the roughness of the slope by adding an angle in the normal vector of the triangular plane. The validity of proposed simulation method becomes clear by the application to rockfalls on a simple slope.