DEM study of particle scale effect on plain and rotary jacked pile behaviour in granular materials

TY - JOUR

T1 - DEM study of particle scale effect on plain and rotary jacked pile behaviour in granular materials

AU - Cerfontaine, Benjamin

AU - Ciantia, Matteo O.

AU - Brown, Michael

AU - White, D. J.

AU - Sharif, Yaseen U.

N1 - Copyright: © 2023 Published by Elsevier Ltd.

PY - 2023/9

Y1 - 2023/9

N2 - The capacity of open-ended piles strongly depends on the potential plugging occurring during installation. The Discrete Element Method (DEM) is particularly suitable to the study of pile plugging, as it can model large soil deformation. However, DEM simulation of the 3D boundary value problems is computationally expensive, and particle upscaling is usually used to reduce the number of particles modelled. In this paper, two granular beds were created with the same average porosity, initial stress field and contact parameters, but different particle scales. Two pile geometries were installed by plain and rotary jacking. Normalised results show that the pile penetration mechanism is strongly affected by the particle scale. Larger particles lead to earlier pile plugging, higher shaft resistance and require a greater force to penetrate the ground. This effect can be linked to a modified penetration mechanism, with larger shear zones and less well defined “nose cone” under the pile tip for larger particles. Changing particle scaling has a neutral effect on the total penetration resistance of a rotary jacked pile, but reduces the base penetration and increases the plug resistance. Maximising the ratio of particle scale to wall thickness is key to adequately capturing the pile coring mechanism.

AB - The capacity of open-ended piles strongly depends on the potential plugging occurring during installation. The Discrete Element Method (DEM) is particularly suitable to the study of pile plugging, as it can model large soil deformation. However, DEM simulation of the 3D boundary value problems is computationally expensive, and particle upscaling is usually used to reduce the number of particles modelled. In this paper, two granular beds were created with the same average porosity, initial stress field and contact parameters, but different particle scales. Two pile geometries were installed by plain and rotary jacking. Normalised results show that the pile penetration mechanism is strongly affected by the particle scale. Larger particles lead to earlier pile plugging, higher shaft resistance and require a greater force to penetrate the ground. This effect can be linked to a modified penetration mechanism, with larger shear zones and less well defined “nose cone” under the pile tip for larger particles. Changing particle scaling has a neutral effect on the total penetration resistance of a rotary jacked pile, but reduces the base penetration and increases the plug resistance. Maximising the ratio of particle scale to wall thickness is key to adequately capturing the pile coring mechanism.

KW - Piles

KW - Plugging

KW - Discrete Element Method

KW - Granular material

KW - Pile jacking

KW - Rotary jacking

UR - https://www.scopus.com/pages/publications/85161334482

U2 - 10.1016/j.compgeo.2023.105559

DO - 10.1016/j.compgeo.2023.105559

M3 - Article

SN - 0266-352X

VL - 161

JO - Computers and Geotechnics

JF - Computers and Geotechnics

M1 - 105559

ER -