ABSTRACT:

The first generic class of aseismic foundation design problem relates to the design of new foundations. Once earthquake risk and site effects have been evaluated the designer needs to proceed with the proportioning of the foundation. To date there is little in the way of code based recommendations to cover this. Eurocode 8 (the structural design code in the new Eurocode series) is an exception and contains an extensive section on the design of foundations to resist earthquake loading. This has been developed using the results of a number of special investigations, both laboratory and theoretical. This paper will address the background to the provisions in the Eurocode, will cover shallow foundations and deep foundations, and review differences between low level response for which the soil can be expected to remain elastic and other situations where nonlinear behaviour of the soil adjacent to the foundation occurs.

1.0 INTRODUCTION

At the dawn of the third millenium, aseismic design of foundations still remains a challenging task for the earthquake geotechnical engineer. Leaving aside the seismic retrofit of existing foundations, which is a more difficult issue, even the design of new foundations raises issues which are far from being totally resolved. One of the main reasons stems from the complexity of the problem which requires skills in soil mechanics, foundation engineering, soil-structure interaction along with, at least some knowledge of structural dynamics. A parallel between static design and seismic design reveals some similarity but also very marked differences. It is only with the increase in the understanding of soil behavior and the development of reliable constitutive models that sound predictions of settlements could be achieved. Not surprisingly, earthquake geotechnical engineers have focused their attention on the non linear behavior of soils and on the evaluation of the cyclic deformations of foundations.

This content is only available via PDF.
You can access this article if you purchase or spend a download.