Abstract
The object of this work is to investigate the behaviour of surface strip footings resting on an elastic-perfectly plastic or strain-softening soil (clay). The mathematical theory of plasticity as applied to soil mechanics and both the factors that affect strain-softening behaviour and past design are considered in a literature review. For the purpose of the study, a simple elastic-plastic model based on the Tresca criterion in conjunction with the finite element method using constant strain triangular elements has been adopted throughout the investigation. A plane strain finite element program, developed during the course of the work, is described. A new approach called "displacement control method" has been developed to solve the elasto-plastic problem. A feature of considerable importance is that the "displacement control method" seems to provide a complete picture of the load-settle-ment behaviour and a rather accurate determination of the collapse load of the footing bearing on either an elastic-perfectly plastic or strain-softening soil.