Upper-Bound Solution for Flat Cavity Expansion Model

Abstract

In this paper, an upper-bound solution for the FCEM is proposed to study the effect of the plastic behavior of soil on the interpretation of a flat dilatometer test. Kinematically admissible displacement fields for the FCEM are derived from Zhou’s elastic solutions for an incompressible material. These displacement fields are then used to obtain an upper-bound solution for a FCEM based on energy conservation principles that the sum of the plastic and elastic work of soil is equal to the flat cavity expansion work, with yield being defined using the Tresca yield criterion. The upper-bound solution is validated by comparing the calculated list-off pressure for the flat dilatometer test using both the proposed upper-bound solution to an elastic solution and a series of field test data. The results show that the proposed upper-bound solution is better than the elastic solution in interpreting the flat dilatometer test.