Influence of consolidation on undrained capacity of two interfering footings on heterogeneous clays

Abstract

The effect of consolidation on the undrained capacity of two interfering footings has not been investigated previously in a systematic manner, although this is particularly interest for offshore foundations, where consolidation will occur as a result of working load or preload. This paper presents results of a numerical investigation into the consolidated undrained bearing capacity of two interfering footings resting on heterogeneous clays. Finite difference code FLAC with the modified Cam Clay soil model is applied to couple the effect of consolidation and strength gain of clay beneath the footings. The results are expressed in dimensionless form of the gain in capacity, accounting for the coupling effects of the spacing between two footings, the magnitude and duration of applied preloads, and the clay strength heterogeneity. A design approach based on the data-fitting equations of the obtained solutions is proposed, and the failure mechanisms of the two adjacent footings after consolidation are also discussed.