Dynamic behavior of pile foundations under vertical and lateral vibrations: review of existing codes and manuals

Abstract

Designing structures subjected to dynamic loads is quite complex and involve structural, mechanical, geotechnical engineering and the theory of vibration. Machines, buildings under seismic effect, and wind turbines induce both dynamic and static loads on their foundations. If these structures are supported on piles, a full understanding is required of the dynamic interaction between individual piles and soil (pile-soil interaction) and between adjacent piles (pile-soil-pile interaction). Due to the complexity of this problem, codes and manuals recommend the use of approximate approaches. However, there is a general lack in research concerning the accuracy of these approaches. The present paper aims to help filling this gap by comparing the recommendations from selected codes and manuals with the results obtained from the numerical analysis. The codes and manuals considered in this paper are the Egyptian Code (EC), ACI, and the Canadian Manual (CM). This comparison is held over a range of parameters including excitation force frequency (f), soil modulus of elasticity (Es), pile slenderness Ratio (L/D), dimensionless spacing ratio (S/D) and pile group size (ng). At the end of this study, advantageous and downfalls of these approaches are discussed.