Modeling Aging of Displacement Piles in Natural Soft Clay
Journal article, 2019

A multitude of mechanisms will affect the evolution of the pile response over time, each with their respective time scale. It is shown that most of the processes can be linked to the pile installation stage, which alters the soil surrounding the pile. As a result, there is a change in the mechanical properties of the soil that will influence the subsequent pile response over time. These long-term mechanisms include the dissipation of excess pore pressures from pile installation and the creep in the soil. This paper presents a numerical approach that combines the strain-path method, an advanced effective stress-based constitutive model for soft soils, and a multiphase numerical framework that enables the modeling of the pile installation and subsequent change of pile bearing capacity over time. The presented results demonstrate that the degree of remolding of the soil during the pile installation stage is closely linked to the subsequent pile response. For the Onsøy test case studied, the increase in shaft capacity over time, demonstrated to be linked to undrained strength recovery, could be faithfully reproduced during and after dissipation of excess pore pressures. Hence, pile aging of displacement piles installed in clay is strongly linked to installation effects and the creep and relaxation processes in the soil. Further study is required to fully reveal the physicochemical mechanisms that underpin these processes.

Pile setup

Pile installation

Creep

Pile aging

Author

Mats Karlsson

Chalmers, Architecture and Civil Engineering, Geology and Geotechnics

Jorge Yannie

NCC AB

Chalmers, Architecture and Civil Engineering, Geology and Geotechnics

Jelke Dijkstra

Chalmers, Architecture and Civil Engineering, Geology and Geotechnics

Journal of Geotechnical and Geoenvironmental Engineering - ASCE

1090-0241 (ISSN) 19435606 (eISSN)

Vol. 145 10 04019070

Subject Categories

Geophysical Engineering

Applied Mechanics

Geotechnical Engineering

DOI

10.1061/(ASCE)GT.1943-5606.0002110

More information

Latest update

4/27/2021