Shallow foundation stiffness: Continuous soil and discrete spring models compared

Abstract

In this paper we compare two ways of modelling shallow foundation stiffness. One method assumes that the soil beneath the foundation can be idealised as an elastic continuum and the other that the soil can be represented as a bed of independent springs. The essential difference is that the elastic material is continuous so that a displacement or load at one location induces changes elsewhere, while in the case of springs there is no interaction so that what happens at one spring has no effect on other springs. Modelling with springs is simpler than using a continuous medium and also leads to a simple method for handling progressive uplift of the foundation under moment loading. The question addressed in the paper is how appropriate is the spring model.