FE-based modelling of pile driving in saturated soils

Start Page
894
End Page
900
Citation
Proceedings of the 8th International Conference on Structural Dynamics, EURODYN 2011 : Leuven, Belgium, 4 - 6 July 2011. - Leuven, 2011. - Seite 894-900
Contribution to Conference
8th International Conference on Structural Dynamics, EURODYN 2011 
Scopus ID
2-s2.0-84879550453
Publisher
Katholieke Universiteit Leuven
ISBN
978-90-76019-31-4
The numerical simulation of pile jacking and pile driving in sand by the finite element method to investigate the effects on the surrounding soil and structures has been subject of many research work. Thereby the influence of water was taken into account by generating an initial effective stress state based on the submerged unit weight of the soil. Still this approach is not capable to account for all effects of the pore water on the soil behaviour like the build-up of excess pore pressures in water saturated conditions and the phenomenon of soil liquefaction. For this reasons a multi-phase model was implemented in Abaqus/Standard using a user subroutine of type UEL. The paper describes the basics and the implementation of the multi-phase model. Furthermore a verification example is presented. The main part of the paper deals with a first approach to simulate pile driving in water saturated soils. The finite element model is described and the results concerning the wave propagation, the distribution and evolution of pore water pressure and effective stress are presented. Excess pore water pressures are observed, reducing the effective principal stresses of the soil skeleton. Since the soil stiffness depends on the current stress state and the void ratio when hypoplasticity is used as the constitutive law for the soil skeleton, this also involves a reduction of stiffness, which may have an important influence on the deformation of structures embedded into the soil. The simulation of pile driving in water saturated soils in a more realistic way by a technique comparable to a zipper, which allows the pile to penetrate into the soil continuum, shall be the subject of future research.
Schlagworte
Excess pore pressure
Finite element method
Multi-phase model
Pile driving
Saturated soil
DDC Class
620: Engineering
624: Civil Engineering, Environmental Engineering
690: Building, Construction