Simulations of Landslide Wave Generation and Propagation Using the Particle Finite Element Method

Abstract

In this study, the impulse waves generated by highly mobile slides in large‐scale flume experiments are reproduced numerically with the Particle Finite Element Method (PFEM). The numerical technique combines a Lagrangian finite element solution with an efficient remeshing algorithm and is capable of accurately tracking the evolving fluid free‐surface and velocity distribution in highly unsteady flows. The slide material is water, which represents an avalanche or debris flow with high mobility, and the reservoir depth is varied, thereby achieving a range of different near‐field wave conditions from breaking waves to near‐solitary waves. In situ experimental observations of fluid velocity and water surface levels are obtained using high‐speed digital cameras, acoustic sensors, and capacitance wave probes, and the data are used to analyze the accuracy of the PFEM predictions. The two‐dimensional numerical model shows the capability of holistically reproducing the entire problem from landslide motion, to impact with water, to wave generation, propagation, and runup. Very good agreement with the experimental observations are obtained, in terms of landslide velocity and thickness, wave time series, maximum wave amplitude, wave speed, and wave shape. In a broad perspective, the results demonstrate the potential of this numerical method for predicting outcomes of interacting multi‐hazard scenarios, such as landslides triggered by loss of slope stability and the generation of tsunami.

3D simulation of Vajont disaster. Part 2: Multi-failure scenarios

“…The method combines efficiently a fully Lagrangian Finite Element Method (FEM) solver with a fast remeshing algorithm. The well-suited combination of these two features makes the PFEM an ideal tool for the simulation of landslide impulse wave events, as shown in several previous publications (Salazar et al, 2016;Cremonesi et al, 2011Cremonesi et al, , 2017Zhang et al, 2019;Mulligan et al, 2020). Indeed, on the one hand, the Lagrangian description of the motion allows for a faithful tracking of the deforming shapes of both the landslide and the water bodies and their mutual interfaces, and, on the other hand, the use of a FEM-based solver enables the accurate solution of the complex constitutive behavior used for the landslide material.…”

Wave Generation Across a Continuum of Landslide Conditions From the Collapse of Partially Submerged to Fully Submerged Granular Columns

“…Given the complex coupled motion between particles and fluid, previous studies have relied on physical experiments as tools to investigate landslide‐generated waves by extrapolating observations to analytical and numerical models for hazard assessment (Grilli et al., 2019; Mulligan et al., 2020). The benchmark case of the granular column collapse is often used for the study of landslide mobility and can provide insight into the speed and distal reach of the mass failure as a function of the ratio between the initial column height and the initial width (Cabrera & Estrada, 2019; Lajeunesse et al., 2004; Lube et al., 2004; Roche et al., 2008).…”

A State of the Art Review of the Particle Finite Element Method (PFEM)

“…Zhu et al [136] extended the application field by also considering the presence of solid structures, reproducing the situation of tsunami waves loading on a bridge. Recently [79] showed the successful application of the PFEM to the simulation of water dam break impacting water at rest and creating impulse waves.…”