Research on the numerical model for the routing of viscous debris flow considering the interface

Abstract

Based on the interface theory, taking the corresponding surface of the yielding depth of debris flows as the interface, the viscous debris flows can be divided into the ideal fluid and the Bingham fluid. Thus, a vertical layered numerical model and its relative algorithm are developed to simulate the routing of viscous debris flows. The model is based on the motion feature of the debris and takes the velocity differences of debris flows in different layers into account. Therefore, it reasonably describes the routing mechanism and its impact on the morphology of debris flow due to the flow velocity. In addition, the model fully considers the phenomena of ‘tongue-like’ and ‘debris flow head’ of actual viscous debris flows and thus accurately depicts the motion state of the debris flow during the routing. A series of model experiments are adopted to verify the proposed numerical model and the algorithm. Compared with the measured data, the relative errors of the inundation areas and maximum accumulation thicknesses are within ±5%. Then, the comparison between the proposed model and other models further testifies the rationality of the proposed model.