Undrained Stability of Ring Foundations: Axisymmetry, Anisotropy, and Nonhomogeneity

Abstract

Ring foundations are widely used to support various types of offshore structures because of the cost-effective reason. Unlike the traditional circular foundations, very few studies were reported with regard to the bearing capacity of ring foundations. In addition, the study on the stability effects of anisotropic and nonhomogeneous clays is yet to be found in the current literature. The purpose of the technical note is therefore to bridge the current research gap. By using the robust lower and upper bound finite-element limit analysis in axisymmetric conditions, new stability solutions of ring footings on anisotropic and nonhomogeneous clays are obtained using dimensionless parameters. The associated failure mechanisms are also examined and discussed, while the design equations are proposed for predicting the bearing capacity of ring foundations. The findings in this study provide a reliable solution to improve the current design standard for ring footings in anisotropic and nonhomogeneous clays.