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Three-Dimensional Nonlinear Seismic Analysis of Single Piles Using Finite Element Model: Effects of Plasticity of Soil |
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| Authors: | B K Maheshwari K Z Truman P L Gould M H El Naggar |
| Affiliation: | 1Postdoctoral Researcher, Dept. of Civil Engineering, Washington Univ., St. Louis, MO 63130. 2Professor and Chairman, Dept. of Civil Engineering, Washington Univ., St. Louis, MO 63130. 3Professor, Dept. of Civil Engineering, Washington Univ., St. Louis, MO 63130. 4Associate Professor, Dept. of Civil Engineering, Univ. of Western Ontario, London ON, Canada N6A 5B9. |
| Abstract: | Much of the reported research on the dynamic analysis of pile foundations assumes linear behavior of soil that may not be valid for strong excitations. In this paper, material nonlinearity of the soil caused by plasticity and work hardening is considered in the dynamic analysis of pile foundations. An advanced plasticity based soil model, HiSS, is incorporated in a finite element technique. To simulate radiation effects, proper boundary conditions are used. The model and algorithm are verified with analytical results that are available for elastic and elastoplastic soil models. Analyses are carried out for free-field response and pile head response of end-bearing single piles. Both harmonic and transient excitations are considered in the analyses. Effects of frequency of excitation and stiffness of soil are investigated. It was found that the nonlinearity of soil has significant effects on the pile response for lower and moderate frequencies of excitations (a0<0.6) while at higher frequencies its effects are not as significant. |
| Keywords: | Plasticity Soils Pile foundations Seismic response Seismic analysis Finite elements Boundary conditions |