DEM SIMULATION ON DEHYDRANT BEHAVIOR OF DEBRIS FLOW CAPTURED BY BOTTOM DRAINAGE SCREEN DAM

Abstract

This paper presents a new Distinct Element Method to simulate coupled behavior of water and gravels. A spherical shape water element is proposed. The element has an isotropic pressure controlled by shrinkage volume of its body, and transfers the pressure to adjacent elements in proportion to the contact section area. Combining the water elements and conventional element, i.e., spherical or aggregate rigid body experiments, debris flow behavior obtained by experiment are simulated. The experiments are performed on the dehydrate behavior of debris flow captured by a bottom drainage screen dam. Draining out water from debris flow, the gravels lose its fluidity on the screen. The proposed method simulates such behaviors very well, and the coupled mechanism is analyzed in viewpoints of reaction force between rigid and water elements, and coordination number transition in the rigid elements.