Numerical analysis of irrigation canal on collapsible soil using a critical state model

Abstract

This paper presents a critical state model for unsaturated soils, showing the implementation in a finite elements program and applications of the model. Compared with Cam clay for saturated soils, this model, proposed initially by Wheeler & Sivakumar (1995) and modified by Silva Filho (1998), uses a state variable of stress additional to represent the suction effect in the unsaturated soils, using the technical of initial deformation. In this model the parameters can be obtained from simple experiments, like the oedometric double test. With intuit emphasize the importance of the utilization of a simple procedure in elasto-plastic model in unsaturated soils, are introduced three analyses:  analysis of the saturation procedure, verification of the results presented by Lawton et ai. (1989 and 1991) and a collapse new study of Bom Jesus da Lapa Irrigation Canal in Bahia state, Brazil.