| Popis: |
In a soil-structure interface test, the soil sample consists of two parts: the soil mass and the interface layer. In the previous experimental investigations of the soil-structure interface problems, the soil deformation in the interface layer was not measured separately from the soil deformation in the soil mass. Consequently, most of the previous numerical interface models were based on the combined deformation of the interface layer and soil mass. The main objective of this research was to determine the stress-deformation behaviour of soil in the interface layer. The existing interface apparatus, C3DSSI, was set up to measure separately the tangential displacement due to the deformation of the sand sample, which included the soil mass and the interface layer, and the displacement due to sliding at the contact surface. Digital photography was used effectively to determine the deformations of sand in the interface layer separate from the sand mass. Experiments showed that strain localization takes place in the interface layer and the thickness of the interface layer increases gradually as the shear stress increases during a test. A Fortran program for Lade's model was written to simulate numerically the sand-steel interface behaviour. The simulation consisted of two sections: the simulation of the behaviour of the sand mass, and the simulation of the sand behaviour in the interface zone. Comparisons were made between the results of the numerical modelling and the experimental results. These comparisons showed that Lade's work hardening model can be used with moderate success for the simulation of interface behaviour. |
