Location

New York, New York

Session Start Date

4-13-2004

Session End Date

4-17-2004

Abstract

The effects of material nonlinearity of soil on dynamic behavior of a single pile and pile groups are investigated. An advanced plasticity based soil model, HiSS, is incorporated in the finite element formulation. To simulate radiation effects, proper boundary conditions are used. The model and algorithm are verified with analytical results that are available for elastic and elasto-plastic soil models. Analyses are performed for seismic excitation as well as for loads applied on the pile cap and the effect of nonlinearity is investigated. Effects of spacing between piles are investigated. It was found that the effect of soil nonlinearity on the seismic response is very much dependent on the frequency of excitation. At low frequencies, its effect is significant but at higher frequencies it is negligible. For the loading on a pile cap, the nonlinearity decreases the dynamic stiffness of the soil-pile system. Effect of nonlinearity on the dynamic stiffness is shown to be sensitive to the spacing between piles. Nonlinearity suppresses wave interference effects among piles and thus reduces the stiffness significantly at excitation frequencies where the group effect is most important.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Fifth Conference

Publisher

University of Missouri--Rolla

Publication Date

4-13-2004

Document Version

Final Version

Rights

© 2004 University of Missouri--Rolla, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Apr 13th, 12:00 AM Apr 17th, 12:00 AM

Nonlinear Dynamic Behavior of Pile Groups: Effects of Plasticity of Soil

New York, New York

The effects of material nonlinearity of soil on dynamic behavior of a single pile and pile groups are investigated. An advanced plasticity based soil model, HiSS, is incorporated in the finite element formulation. To simulate radiation effects, proper boundary conditions are used. The model and algorithm are verified with analytical results that are available for elastic and elasto-plastic soil models. Analyses are performed for seismic excitation as well as for loads applied on the pile cap and the effect of nonlinearity is investigated. Effects of spacing between piles are investigated. It was found that the effect of soil nonlinearity on the seismic response is very much dependent on the frequency of excitation. At low frequencies, its effect is significant but at higher frequencies it is negligible. For the loading on a pile cap, the nonlinearity decreases the dynamic stiffness of the soil-pile system. Effect of nonlinearity on the dynamic stiffness is shown to be sensitive to the spacing between piles. Nonlinearity suppresses wave interference effects among piles and thus reduces the stiffness significantly at excitation frequencies where the group effect is most important.