Seismic Bearing Capacity of Strip Foundations with Nonlinear Power-Law Yield Criterion Using the Stress Characteristics Method

Abstract

The computations of the bearing capacity of foundations have generally been carried out with the usage of the Mohr-Coulomb failure criterion—a linear yield envelope in a shear stress–normal stress plot. However, as noted from many experimental observations, the failure criteria associated with most geomaterials are generally nonlinear. A novel computational analysis, based on the stress characteristics method, has been performed in the current study to compute very accurately the seismic bearing capacity of a rough strip foundation considering a nonlinear power-law yield criterion. The analysis incorporates the effect of pseudostatic horizontal seismic inertial forces. The obtained results can, however, be used to include even the effect of the vertical component of the seismic inertial forces. The present formulation is based on the consideration of a curvilinear nonplastic trapped wedge below the footing base. By carrying out a detailed parametric analysis, the effects of different material shear strength parameters, overburden pressure, seismic forces, and foundation width on the bearing capacity factor Nσ have been examined. With the changes in horizontal seismic acceleration coefficients, the slip line patterns have also been explored. The results from the present analysis compare quite well with that reported from studies available in the literature.