Effect of spatial variability on the behaviour of shallow foundations: Centrifuge study

This paper presents the results of a reduced-scale model of a vertically loaded single rigid strip footing resting on a spatially varying soil. The experimental work was carried out in a mini geotechnical centrifuge, and a micro loading system was developed. A total of 35 bearing capacity tests were performed, 30 tests resting in heterogeneous soils and 5 in homogeneous soils. The heterogeneous models match three different random fields that are defined by three coefficient of variations of the liquid limit, COVWL 51%, 30% and 13%. Results show a reduction in the mean bearing capacity of the heterogeneous soils compared with the corresponding bearing capacity of the homogeneous soils that have the same mean property. Particle Image Velocimetry (PIV) analysis was made for analyzing the failure mechanisms. Results show that the inherent spatial variability of the soil properties can modify the basic form of the failure mechanism drastically.