Search

A macroscopic model that consists of distributed hysteretic springs and frequency dependent -pots is utilized to model the lateral soil reaction and a practical method based on one-dimensional finite element formulation is developed to compute the nonlinear response of single piles under dynamic lateral loads. The model is physically motivated, adequate for cohesive and cohesionless soils, and involves standard geotechnical parameters. Only two parameters have to be calibrated by fitting experimental data. Hysteretic and radiation damping are modeled realistically within the practical range of amplitudes and frequencies. The model is calibrated and validated against five well instrumented full-scale experiments and typical values for the range of the model-parameters are provided. Subsequently, the developed model is utilized to study the nonlinear seismic response of single piles. Finally, the developed method and the calibrated model are used to predict the inertial and seismic response of one of the piles used in the foundation of the Ohba bridge near Tokyo, Japan.

A simple analytical solution is presented to calculate the pile-soil-pile interaction and eventually the dynamic response or pile groups when excited by the passage or Rayleigh waves and obliquely incident SH-waves. A dynamic Winkler model, with realistic frequency-dependent «springs» and «dashpots» in conjunction with physically motivated approximations is utilized to compute the wave field radiating from an oscillating pile and the effect or this field on an adjacent pile. The coupled rocking motion or the pile group resulting from Rayleigh waves and the torsional motion or the pile group resulting from SH-waves is accurately predicted by a simple mathematical expression. The results or the presented method can be obtained with'hand calculations'and are in excellent agreement with results from «rigorous» solutions based on integral equation formulations. It is round that the group response is primarily affected from the phase difference or the input seismic motion at the location or each pile (wave-passage effect). Pile-soil-pile interaction has insignificant effect and can be neglected

A simple integrated procedure to analyze the problem of soil‐pile‐foundation‐superstructure interaction is presented. The procedure combines the available theories for the computation of the dynamic impedances and kinematic‐seismic response factors of pile foundations with a simple six‐degree‐of‐freedom structural model. The procedure is used to predict the response of the Painter Street Bridge located at Rio Dell, California, which was excited by the 1992 Petrolia earthquake. The predicted response with the proposed procedure is in very good agreement with recorded data, and the significance of considering the frequency dependent pile‐foundation impedances in predicting the superstructure response is demonstrated.