Modelling of landslides using the material point method

On Friday 16 June 2023, the event entitled "Modelling of landslides using the material point method" will be held at the Aula Albenga of the Politecnico, and will have Luigi Pugliese as guest speaker - Research Fellow in Geotechnical Engineering at University of Calabria.

Abstract

Movement and failure mechanisms of slopes are generally categorised into four different stages: pre-failure, failure, post-failure and reactivation (Leroueil et al., 1996). The mechanical phenomena involved in these stages differ from each other. This makes an analysis of the entire deformation process very complicated to be performed. Conventional numerical techniques such as the finite element method (FEM) or the finite difference method (FDM), can be effectively used to predict the deformation processes occurring in the slopes in the pre-failure and failure stages under the assumption of small strains. However, serious numerical drawbacks could arise due to mesh distortions when large deformations occur, for example during the post-failure stage of landslides.

As a consequence, these methods are unable to analyse the run-out process of landslides. Among the available numerical techniques, the material point method (MPM) is undoubtedly one of the most attractive to overcome the limitations of the traditional methods in the study of geotechnical problems involving large deformations. In this presentation, MPM is used to analyse the complete deformation process of natural slopes taking also into account the brittleness of soils, the progressive failure developing during the pre- failure stage and the characteristics of the post-failure movements. In this context, a novel procedure based on the results of direct shear tests is presented to reduce the effects of the mesh dependency on the numerical solution. This procedure is completely analytical and requires few parameters of simple experimental determination and with a clear physical meaning. Some landslides that occurred in Southern Italy are analysed using the proposed approach.

The obtained results demonstrate that an adequate analysis of the slope deformation process, including the post-failure stage, can lead to a better understanding of the complex mechanisms that characterise the landslides. Moreover, a predictive analysis of this stage is very useful for assessing the risk associated with the landslide occurrence and establishing the most suitable measures for slope stabilization.

For more information contact renato.cosentini@polito.it

Event organised by the Department of Structural, Geotechnical and Building Engineering - DISEG of the Politecnico.