Finite Deformation Modelling of Cone Penetration Tests in Saturated Structured Clays

TY - GEN

T1 - Finite Deformation Modelling of Cone Penetration Tests in Saturated Structured Clays

AU - Ciantia, Matteo O.

AU - Oliynyk, Kateryna

AU - Tamagnini, Claudio

N1 - Publisher Copyright: © 2022 Springer Nature Switzerland AG. Part of Springer Nature.

PY - 2023

Y1 - 2023

N2 - In this work, the complex coupled deformation and flow processes occurring in the soil around a CPTu penetrometer during a test in structured natural clays are investigated by means of the Geotechnical Particle Finite Element Method (GPFEM) code. The GPFEM implementation adopted incorporates a fully coupled hydro-mechanical formulation, based on regularized, mixed low-order linear strain triangles. To capture the relevant features of the mechanical response of natural structured clays, the soil behaviour is described using a finite deformation, non-associative elastic-plastic model for this class of geomaterials, referred as FD_Milan model. The model formulation is based on a multiplicative decomposition of the deformation gradient and on the adoption of an elastic response based on the existence of a suitable free energy function. Two bonding-related internal variables, quantifying the effects of structure on the yield locus, are incorporated to provide a macroscopic description of mechanical destructuration effects. To deal with strain localization phenomena, the model is equipped with a non-local version of the hardening laws. The numerical model has demonstrated capable of capturing the destructuration associated with plastic deformations around the cone tip; the space and time evolution of pore water pressure as the cone tip advances; the effect of soil permeability on predicted excess pore water pressures, and the effect of soil bonding on predicted values of cone tip resistance.

AB - In this work, the complex coupled deformation and flow processes occurring in the soil around a CPTu penetrometer during a test in structured natural clays are investigated by means of the Geotechnical Particle Finite Element Method (GPFEM) code. The GPFEM implementation adopted incorporates a fully coupled hydro-mechanical formulation, based on regularized, mixed low-order linear strain triangles. To capture the relevant features of the mechanical response of natural structured clays, the soil behaviour is described using a finite deformation, non-associative elastic-plastic model for this class of geomaterials, referred as FD_Milan model. The model formulation is based on a multiplicative decomposition of the deformation gradient and on the adoption of an elastic response based on the existence of a suitable free energy function. Two bonding-related internal variables, quantifying the effects of structure on the yield locus, are incorporated to provide a macroscopic description of mechanical destructuration effects. To deal with strain localization phenomena, the model is equipped with a non-local version of the hardening laws. The numerical model has demonstrated capable of capturing the destructuration associated with plastic deformations around the cone tip; the space and time evolution of pore water pressure as the cone tip advances; the effect of soil permeability on predicted excess pore water pressures, and the effect of soil bonding on predicted values of cone tip resistance.

KW - CPTu tests

KW - PFEM

KW - Non-local finite deformation plasticity

KW - Structured soils

UR - https://www.scopus.com/pages/publications/85136329696

U2 - 10.1007/978-3-031-12851-6_24

DO - 10.1007/978-3-031-12851-6_24

M3 - Conference contribution

SN - 9783031128509

T3 - Lecture Notes in Civil Engineering

SP - 195

EP - 202

BT - Challenges and Innovations in Geomechanics

A2 - Barla, Marco

A2 - Di Donna, Alice

A2 - Sterpi, Donatella

A2 - Insana, Alessandra

PB - Springer

T2 - 16th International Conference on IACMAG 2022

Y2 - 30 August 2022 through 2 September 2022

ER -