NUMERICAL SIMULATION ON DEBRIS-FLOW WITH DRIFTWOOD AND ITS CAPTURING DUE TO JAMMING OF DRIFTWOOD ON A GRID DAM

摘要

A two-dimensional numerical model is developed for computing the characteristics of debris flow with driftwood and its capturing process due to jamming of driftwood on a grid dam. Equations of the rotational motion and the translational motion of driftwood are evaluated dynamically in the Lagrangian form. A numerical model is developed with an interacting combination of Eulerian expression of the debris flow and Lagrangian expression of the driftwood, in which the fluctuation components of the position and the rotational angular velocity of the driftwood are dealt with stochastically. The jamming of driftwood on a grid dam is evaluated based on the geometric conditions and probabilistic approaches. The simulated results of outflow discharge and driftwood agree well with the experimental results.