Simulation of debris flow on an instrumented test slope using an updated Lagrangian continuum particle method

• Published in: Acta geotechnica Vol. 15; no. 10; pp. 2757 - 2777
• Main Authors: Fávero Neto, Alomir H., Askarinejad, Amin, Springman, Sarah M., Borja, Ronaldo I.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-10-2020; Springer Nature B.V
• Subjects: Cohesion; Complex Fluids and Microfluidics; Computational fluid dynamics; Computer simulation; Debris flow; Deforestation; Deformation; Detritus; Engineering; Failure surface; Flow duration; Flow velocity; Fluid flow; Foundations; Free surfaces; Geoengineering; Geotechnical Engineering & Applied Earth Sciences; Hydraulics; Hydrodynamics; Kinematics; Mathematical models; Mechanical properties; Model testing; Nonlinear systems; Nonlinearity; Rain; Rainfall; Research Paper; Robustness (mathematics); Sediment; Sediments; Simulation; Smooth particle hydrodynamics; Soft and Granular Matter; Soil Science & Conservation; Solid Mechanics; Strain concentration; Three dimensional flow; Three dimensional models; Smoothed particle hydrodynamics; Debris flow; Meshless method; Debris slide; Granular flow; Updated Lagrangian; Slope
• ISSN: 1861-1125; 1861-1133
• DOI: 10.1007/s11440-020-00957-1

We present an updated Lagrangian continuum particle method based on smoothed particle hydrodynamics (SPH) for simulating debris flow on an instrumented test slope. The site is a deforested area near the village of Ruedlingen, a community in the canton of Schaffhausen in Switzerland. Artificial rainfall experiments were conducted on the slope that led to failure of the sediment in the form of a debris flow. We develop a 3D mechanistic model for this test slope and conduct numerical simulations of the flow kinematics using an SPH formulation that captures large deformation, material nonlinearity, and the complex post-failure movement of the sediment. Two main simulations explore the impact of changes in the mechanical properties of the sediment on the ensuing kinematics of the flow. The first simulation models the sediment as a granular homogeneous material, while the second simulation models the sediment as a heterogeneous material with spatially varying cohesion. The variable cohesion is meant to represent the effects of root reinforcement from vegetation. By comparing the numerical solutions with the observed failure surfaces and final free-surface geometries of the debris deposit, as well as with the observed flow velocity, flow duration, and hot spots of strain concentration, we provide insights into the accuracy and robustness of the SPH framework for modeling debris flows.