The behaviour of footings resting on a non-homogeneous soil mass with a crust. Part II. Circular footings

Abstract

The behaviour of circular footings resting on a non-homogeneous elastic soil with a crust is investigated. The stiffness of the crust is assumed to be either constant or to decrease with depth, whereas the stiffness of the underlying soil increases linearly with depth.Consideration is given to the effect of layer depth, crust depth, and the rate of variation of stiffness within the crust and the underlying soil upon the settlement profile. The behaviour of circular footings is then compared with that of strip footings and the relative importance of the crust and the underlying soil parameters is discussed.The influence of cross-anisotropy upon footing response is briefly examined and the effects of neglecting anisotropy are indicated for a number of soil profiles.The results of this study are presented in the form of influence charts which may be used in hand calculations to estimate the settlement of circular footings for a wide range of practical cases. The use of these charts is illustrated by means of a worked example.