Centrifuge tests of shallow footing behaviour on sand under combined vertical-torsional loading

Abstract

Extensive laboratory model tests at earth’s gravity (1g) have been performed during the last two decades to investigate the behaviour of shallow foundations under combined loading. These results have been extremely useful to understand the mechanisms taking place and to design a framework to predict the response of foundations under such loading conditions. The potential scale effects associated with the 1g conditions and the extrapolation of the small model results to large prototype foundations, particularly for testing in sand, however, have only been partially investigated. This paper describes a series of lg tests and centrifuge tests performed on shallow circular foundations on sand subjected to combined vertical and torsional loading. The results are discussed within the framework of displacement-hardening elastic-plastic macroelement modelling, with emphasis on the difference between the lg results and the centrifuge results and its consequences for the performance of the framework.