Nonlinear finite element analysis of stresses and deformations beneath rigid footings

Abstract

Nonlinear finite element analysis was carried out to investigate the stress distribution and load-settlement behaviour of uniformly loaded circular footings of absolute rigidity and absolute flexibility. An absolutely rigid footing was modelled by simulating the footing as a rigid body undergoing equal vertical displacements at the contact points. The nonlinearity of the stress-strain curve of soil was taken into account by adopting a "piecewise" linear model. A hyperbolic stress-strain relationship of the soil was assumed, and Mohr-Coulomb yield criterion was chosen for analysis. An analysis was carried out under conditions simulating the experimental setup of the model footing tests, performed on two different types of soil media. Theoretical observations were compared with experimental ones and good agreement between the above two was found. Thus, reasonable predictions of the effect of relative rigidity of footing in the nonlinear range of soil mass could be obtained and a set of conclusions are arrived at from the present investigation.