The application of 3-dimensional dda with a spherical rigid block for rockfall simulation

Discontinuous Deformation Analysis (DDA), developed in 1984, is an effective dynamic numerical method for solving problems in the rock engineering field. In this paper, a new approach of 3-dimensional DDA with a spherical rigid-block is proposed for the purpose of simulating the behaviour of falling rock from a rock slope. The theory and the mechanism of this research to model rockfall are briefly introduced. The proposed method simplifies the formulation of the displacement function and contact condition due to the adoption of the spherical- rigid-block. Furthermore, a preliminary application is presented to demonstrate the applicability of this new method to practical problems. The application involves the simulation of rockfall on the rock slope, which is located in Hida Mountains in Japan. In comparison with the calculation results of the mass system analysis, 3-dimensional DDA with spherical rigid block is shown to be effective in modelling various modes of rockfall movement and predicting the trajectory of the falling rocks.