Bearing Capacity Factors of Flat Base Footing by Finite Elements

Abstract

This paper presents the computations of vertical bearing capacity factors Nc, Nq, and Nγ, of the smooth and rough strip, circular and ring footings resting on soil with a friction angle (ϕ) ranging from 5° to 45° using a finite element viscoplastic strain method obeying the Mohr-Coulomb yield criterion. The numerical difficulty could be improved to some extent by using the proper magnitude of soil dilation angle (ψ) in the analysis of high non-associative flow. The effects of domain and mesh size are presented thoroughly. The factors are calculated individually and found to be in close agreement with the existing solutions. However, differences are also reported and discussed. The magnitude of bearing capacity factors increases with increasing ϕ. Moreover, the factors with a rough base are significantly greater than the smooth base at high values of ϕ. Moreover, this work also indicates that the shape factors may depend on ϕ.