Investigating the Potential of the Material Point Method to Model the Run-Out Behavior Observed in Centrifuge Experiments

Improving the prediction of landslides and debris flow is essential to understand and mitigate the risks they pose. The material point method (MPM) is a hybrid Eulerian-Lagrangian approach that uses an Eulerian grid to compute the momentum and collisions while Lagrangian particles are used to track the material state. Thus, it is a methodology well suited to model large deformations without issues such as mesh distortion. However, while existing literature has demonstrated the potential of this method with comparisons to general observations from field data, there is a lack of validation against experimental data of run-out in the field of landslides. In this study, the results from recent centrifuge results idealizing a dam breach are used to illustrate the vastly different run-out behaviors fine-grained materials can show, ranging from static liquefaction and rapid run-outs to seepage and slope instability driven run-outs occurring at a much slower rate. Ultimately, the experiments showed that the state parameter, measured or inferred from CPTs, can be used to distinguish between the dominant deformation and failure mechanisms. This paper presents preliminary results from MPM analyses of element tests and small column collapses with a focus on material properties reflecting the state parameter. This motivates the use of MPM with constitutive models utilizing an effective stress-based interpretation of the material response to be applied to landslides, debris flows, and other run-out problems of civil engineering interest.