IDENTIFICATION OF DEM PARAMETERS FOR ROCKFALL SIM ULATION ANALYSIS

Distinct element method(DEM) provides a powerful analytical tool for modeling rockfall behaviors,i.e. trajectories,velocities and energies of falling rocks. Better DEM prediction of the motion of the falling rock requires realistic input parameter values used for the analysis. A methodology is developed in which the DEM parameters are determined from back analysis of a rockfall trajectory observed in field rockfall experiments or traced by site investigation of natural rockfall events. A number of techniques and strategies are proposed to ensure the efficiency and robustness of the solution procedure. The method is also extended into non-homogeneous slope cases,by applying repeatedly the presented procedure to each of the homogeneous segments along a given rockfall trajectory. Laboratory rockfall experiments on small model slopes are carried out to verify the proposed method. Case studies on well-documented rockfall records are also presented to show good performance of the method for both homogeneous and non-homogeneous slopes.