Ultimate Behavior of Continuous Footings in Tensionless Contact with a Three-Parameter Soil

The paper presents an analytical study of the behavior of rigid-perfectly plastic continuous slab foundations indenting a three-parameter soil (Kerr model) under the action of statically increasing applied line load. Simple formulas are obtained for critical loads, maximum surface settlements, foundation distortions, and soil reactions in terms of the load intensity, before and after the plate has been transformed into a mechanism. Two distinct phases of meta-plastic behavior are identified depending on whether or not full contact is maintained between soil and foundation. The results are compared with those obtained for a Winkler medium and an elastic continuum halfspace as well as with experimental data. Finally, the phenomenon of punching shear failure in the soil under the foundation perimeter is also investigated through a simple extension of the three-parameter model.