Influence of Soil Plasticity on the Seismic Performance of Pile Foundations – a 3D Numerical Analysis

This paper presents a detailed analysis of the influence of plasticity on the seismic response of pile foundations. Since soils exhibit nonlinear and irreversible behaviour, it is of major interest to consider plasticity in the design of pile foundations for structures which may be subjected to severe earthquake loading. The study is carried out using a full three-dimensional finite difference modeling using a real earthquake record. The influence of soil plasticity is investigated on the seismic response of soil- pile-structure system for two idealized soil deposits: cohesive and frictional soils. Analyses provide valuable information on the influence of plasticity on the seismic response of soil-pile-structure systems. They show that the soil state in the vicinity of piles head dominates the piles response and may lead to higher deflection and bending stresses.