The Bearing Capacity of Footings on Cohesionless Soils

In 1920 Prandtl published an analytical solution for the bearing capacity of a maximum strip load on a weightless infinite half-space. This solution was extended by Reissner in 1924 with a surrounding surcharge.
Keverling Buisman (1940) extended the Prandtl-Reissner formula for the soil weight. It was Terzaghi (1943) who wrote this in the form which is nowadays used. Since then several people proposed equations for the soil-weight bearing capacity factor. In this paper, we show that all those equations assume a Prandtl failure mechanism, while Finite Element Modelling (FEM) of strip footings on cohesion less materials proofs a global failure mechanism. Also these equations result in a higher bearing capacity than found with FEM. This means that the currently used equations for the soil-weight bearing capacity factor, and also the corresponding shape factor, are inaccurate and unsafe. Therefore new equations for the soil-weight bearing capacity factor, the soil-weight shape factor and the surcharge shape factor have been presented in this paper.