Rupture sismique des fondations par perte de capacit\'e portante: Le cas des semelles circulaires

TL;DR

This paper investigates the seismic bearing capacity of circular foundations on heterogeneous cohesive soils, combining case studies with theoretical bounds to extend existing norms for better earthquake-resistant design.

Contribution

It introduces a kinematic approach to determine upper bounds of seismic loads on circular footings on heterogeneous soils, extending current European norms.

Findings

Established optimal upper bounds for seismic loads

Validated theoretical models with case history data

Proposed simplified guidelines for design

Abstract

Within the context of earthquake-resistant design of shallow foundations, the present study is concerned with the determination of the seismic bearing capacity of a circular footing resting on the surface of a heterogene-ous purely cohesive semi-infinite soil layer. In the first part of the paper, a database, containing case histories of civil engineering structures that sustained a foundation seismic bearing capacity failure, is briefly pre-sented, aiming at a better understanding of the studied phenomenon and offering a number of case studies useful for validation of theoretical computations. In the second part of the paper, the aforementioned problem is addressed using the kinematic approach of the Yield Design theory, thus establishing optimal upper bounds for the ultimate seismic loads supported by the soil-footing system. The results lead to the establishment of some very simple guidelines that extend the existing formulae for the seismic bearing capacity contained in the European norms (proposed for strip footings on homogeneous soils) to the case of circular footings and to that of heterogeneous cohesive soils.