Bearing Capacity of Nonhomogeneous Clay Layers under Embankments

Abstract

The slip‐line method is used to calculate limit loads on layers of weak soil. A horizontal load component of arbitrary intensity is accounted for. The soil is considered cohesive, with the undrained shear strength increasing with depth. The slip‐line solutions presented are proved to be lower bounds to the true limit loads. The upper‐bound results are also presented, though the details of the solution are omitted. Limit loads are presented in the form of graphs. The total load on the foundation soil from embankments is vertical and equal to the weight of the embankment fill. The outward‐acting symmetrical tangential load under unrein‐forced embankments is caused, however, by the horizontal thrust in the embankment fill. A simple method for calculating this horizontal load is suggested, and a proposal for arriving at failure heights of both unreinforced and reinforced embankments is given. A failure height calculation for a case history is presented. Also, a generic example of critcal height prediction for a reinforced and an unreinforced embankment is shown.