A model for geotechnical analysis of flow slides and debris flows

Abstract

Flow slides and debris flows incorporate a broad range of sediment–fluid mixtures that are intermediate between dry rock avalanches and hyperconcentrated flows. Following a comprehensive review of some existing analytical approaches to debris flow runout analysis, a new analytical model based on energy conservation has been formulated. The new analytical model was developed to deepen the understanding of fundamental aspects in modeling of granular flows and to improve the geotechnical mobility analysis of flow slides and debris flows. The Lagrangian finite difference method was used to solve the governing equations. The model and numerical scheme have been tested against analytical solutions and experiments of granular flows with simplified geometries for sliding mass and basal topography. Results of granular flow simulations indicate that the model based on energy conservation performs well and is robust. The model can be used for geotechnical analysis of a wide range of dense granular flows, such as flow slides and debris flows.