Numerical evaluation of the bearing capacity factor Nγ′ of ring footings

In this paper, numerical computations using FLAC code are carried out to evaluate the soil bearing capacity factors Nγ′ for both smooth and rough ring footings for low and high friction associated and nonassociated Mohr–Coulomb soils. The results indicate a significant decrease in the value of Nγ′ with an increase in the ratio of internal radius to external radius of the ring. They also indicate that the soil dilation angle influences the value of Nγ′ when the soil displays high nonassociativity for large internal friction angle values. The values of Nγ′ for a rough footing base, especially with greater values of φ, are shown to be significantly higher than those for a smooth footing base. The computational results are presented in the form of design tables and graphs, and compared with previous published results available in the literature.