LOADS ON RIGID BOX BURIED IN NONLINEAR MEDIUM

This paper generalizes the trapdoor problem which originally had been formulated for an incompressible material having a rigid plastic yield condition in shear. Nonlinear medium properties are idealized by piecewise linear relatinships between uniaxial stress and strain and between shear stress and displacement. A closed form solution for a general linear branch is obtained, and a finite element is defined for which the relationship between end forces and end displacements is derived. The iterative solution of the finite element system yields results such as displacement field, normal stress and strain variations, and shear stresses along the slip planes.