ABSTRACT
The pioneering work by De Beer gave evidence that the bearing capacity factor Nγ of shallow foundations on sand decreases with increasing foundation width. This size effect is mainly attributed to the fact that the shear strength in the sand decreases with increasing isotropic stress level. A non linear finite element program which incorporates an advanced kinematic hardening-softening model is used to study this size effect for strip and circular footings. The constitutive model is calibrated for a given sand. Results of the finite element program are compared with experimental results obtained from literature on shallow foundations. The size effect on the shape factor sγ and the allowable bearing pressure is also investigated. A criterion which governs the safety of a foundation on Nevada sand in the range of widths from 1m to 6m is presented with a shape factor for the allowable bearing pressure.
