Numerical analysis of slab foundations on reactive soils incorporating sand cushions

摘要

This paper explores the effect of the sand cushion as a well-known remedial technique for foundations on reactive soils. Yet, instead of exploring the effect of the sand cushion on the soil and footing movements, this study contributes, for the first time, to reduce the slab foundation design thickness, using a specific depth of sand cushion, thus superseding the empirical approaches currently utilised in the estimation of the sand cushion thickness. To achieve this goal, an intensive parametric study was carried out on different slab dimensions, in different soil classes, and using different construction types, with the inclusion of 3 commonly used depths of the sand cushion. The study utilises a sophisticated three-dimensional (3D) hydro-mechanical finite element (FE) numerical model presented and validated by the authors in previous work (Shams et al., 2018). The same model was implemented in the parametric study of the current research in coupled flow-deformation and stress analyses with the presence of sand cushion. The results of the parametric study were used to generate design equations using the artificial intelligence technique. A computer program was developed for the design of stiffened slab foundations considering the effect of specific depth of sand cushion, which can be readily used by practitioners.