Coupled DEM-FDM simulation of cone penetration tests in coarse grained soils

Mussie Kidane,Roberto Cudmani,Andrés Alfonso Peña Olarte,M.A Aguirre,S Luding,L.A Pugnaloni,R Soto

doi:10.1051/epjconf/202124911012

Mussie Kidane, Roberto Cudmani + Show 5 more

Open Access

https://doi.org/10.1051/epjconf/202124911012

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Abstract

The numerical modelling of geotechnical problems often poses major challenges when large displacements and strain localization are involved. Conventional continuum mechanical approaches like the finite element method (FEM) or the finite difference method (FDM) suffer from mesh distortion and numerical inaccuracy when large deformations are involved. In addition, they require the use of appropriate constitutive models to simulate the soil behaviour. The distinct element method is a promising alternative for large deformation analyses. It does not have the limitations resulting from the numerical discretization of the continuumand not need a constitutive model since the macroscopic response results from the individual particle interaction. However, the maximum number of particles and therefore the domain of the simulation is nowadays limited by the available computational capacity. To overcome this limitation, a coupled DEM-FDM approach is proposed used to optimize the number of particles for a combined numerical domain consisting of areas of large and small displacements. The performance of the coupled DEM-FDM approach is investigated by simulating cone penetration tests in coarse grained soils.

Highlights

Simulating geotechnical boundary-value problems can cause major challenges when large displacements are involved as in the case of debris flow, soil-structure interaction during pile installation and soil liquefaction
The distinct element method is a promising alternative for large deformation analyses
It does not have the limitations resulting from the numerical discretization of the continuum- and not need a constitutive model since the macroscopic response results from the individual particle interaction

Summary

Introduction

Simulating geotechnical boundary-value problems can cause major challenges when large displacements are involved as in the case of debris flow, soil-structure interaction during pile installation and soil liquefaction. The computation effort and time increase with the number of particles limiting the total number of particles that can be modelled with the commonly available computer capacity To overcome this limitation a coupled DEMFDM, in which discrete elements are used in the largedeformation zone and a continuum is assumed outside this zone. The main goal of this contribution is the implementation of a tool for the numerical solution of large deformation problems in geotechnical engineering, such as pile installation and cone penetration in coarse granular soils using coupled DEM/FDM analyses. In this contribution the perspectives of a coupled analyses will be shown by simulations of the cone penetration test (CPT)

Cone penetration test for in-situ investigations

Numerical methods

Model conditions

DEM model validation

Validation of the model on a field test and analysis of results

Discussion and outlook