The purpose of this study is to learn the coefficients of restitution, rotational motions and energy ratio for spherical boulder impacting on the two type slopes. Furthermore, this paper explains effect of difference of slope materials on the above parameters. The parameters for spherical boulder impacting on the slopes will be presented based on our experimental data by free-fall-rebounding test. In order to capture the trajectories of falling and rebounding spherical boulder onto the rock and sandy slopes, a high-speed video camera capable of capturing 3,000 f.p.s. is used.
As the result, the value of coefficients of restitution and energy ratio after impact differ on the rock and sandy slopes. The differences of rockfall motion on the rock and sandy slopes are closely related to their friction coefficient, energy loss, and rotational momentum. Therefore, the slope materials are one of the factors that greatly affect the value of coefficients of restitution and energy ratio after impact.
