Soil–Structure Interaction Analysis of Pile Foundations Subjected to Dynamic Loads

Abstract

Soil–structure interaction (SSI) analysis has been recognized to be an essential step in the design of important structures. With the advent of powerful computers, SSI analysis capabilities have increased by leaps and bounds. This article presents recent research on dynamic SSI analysis of pile-supported structures using direct- and substructure-based numerical techniques. Dynamic response of pile foundations is a frequency-dependent problem. Experimental studies as well as numerical simulations, discussed in the article, reveal characteristics of single and group piles under dynamic loads. It was observed that dynamic lateral stiffness of piles is reduced significantly by cyclic loading. Peak displacement amplitude of pile–clay system, under dynamic loads, was observed to decrease significantly when consistency of clay changes from soft to medium stiff. Finite element analyses were able to simulate the frequency response of a single pile, with admissible accuracy. Flexible volume substructuring using the program SASSI 2010, for seismic response of pile foundations, is discussed with two case studies. The substructure-based SASSI analysis is found to produce results which are in agreement with analytical and experimental results. However, the choice of analyses tools for pile-supported structures is to be made after weighing the computational cost and complexity of numerical models.