Study on Ground Motion Characteristics of River-bed Caused by Debris Flow after an Earthquake Using Distinct Element Method

Abstract

The river-bed ground motion caused by debris flow after an earthquake were simulated using the distinct element method by letting a falling rock collide with the rock surface regarded as river-bed. The characteristics and origin of motion were mentioned by comparing the calculated ground motions with the conditions of changing the rigidity of the river-bed, changing the flow speed, changing flow quantity and considering water. The frequency characteristics of the river-bed motion was affected by the rigidity of the river-bed ground without depending on the height of fall, the number of the falling rocks and the existence of water.