Use of von Mises yield criterion for solving axisymmetric stability problems

By using the von Mises yield criterion, a numerical formulation has been proposed for solving an axisymmetric stability problem with the usage of the lower bound limit analysis, finite elements and nonlinear optimisation. The proposed formulation has been employed for computing the bearing capacity factor N-c for an axially loaded circular footing in clays whose cohesion increases linearly with the depth under undrained (phi=0) condition. To check the efficiency of the proposed nonlinear optimisation algorithm, the linear optimisation has also been performed. The results obtained from the present study are found to compare well with the different numerical solutions reported in the literature.