Modelling the behaviour of circular footings under combined loading on loose carbonate sand

A work-hardening plasticity model for the behaviour of rigid circular footings on loose carbonate sand is described. The model incorporates vertical, moment and horizontal force resultants and the corresponding displacements of the footing, and allows predictions of response to be made for any load or displacement combination. The model is a modification of an existing work-hardening model for circular footings on dense silica sand (published by Houlsby and Cassidy, 2002) and is based on a series of specifically designed tests on loose carbonate sand (Byrne and Houlsby, 1998, 2001). Retrospective simulation of the experimental data verifies the model's suitability for use in this soil type and conditions.