Nonlinear Three-Dimensional Numerical Study of Pile Seismic Behavior: Effect of Pile Geometrical Parameters

The behavior of soil-pile systems subjected to earthquake loading depends on many parameters. These parameters can be categorized into three main groups: geometrical parameters of the pile, soil mechanical properties, and loading characteristics. The purpose of this study is to investigate the effect of pile geometrical parameters on the seismic response of soil-pile systems considering soil nonlinear behavior. To this aim, a set of fully nonlinear three-dimensional analyses in the time domain was conducted using the finite difference computer program FLAC3D. The focus of the paper is on the seismic response of the floating single pile embedded in clayey soil and the parametric study was performed to investigate the effect of pile geometrical parameters on its seismic response. To consider soil nonlinear behavior during seismic events, an elastoplastic constitutive law was applied to the soil medium. Also, soil shear modulus reduction with the increase in soil shear strain level was simulated. The results of this study showed that an increase in pile diameter causes an increase in the maximum kinematic bending moment. This increase is proportional to the pile diameter powered by a value. Also, the results showed that effect of pile length on the magnitude of maximum bending moment in pile was not significant. However, the shape of the bending moment distribution diagram and location of the maximum bending moment are strongly affected by pile length.