|M.Sc Student||Allaldin Murad|
|Subject||Effect of Wall Friction on Earth Pressures and Deformations|
in Geotechnical Modeling
|Department||Department of Civil and Environmental Engineering||Supervisor||Professor Mark Lloyd Talesnick|
|Full Thesis text|
The use of centrifuge modeling to study the behavior of geotechnical structures is common in geotechnical research. Laboratory-scale experiments are often performed in a narrow model simulating plain strain conditions. This is problematic because of the soil-boundary interactions’ effects on earth pressure and deformations within the model. This effect is magnified when using PIV monitoring techniques since it studies the kinematics of a soil at points of maximal interaction between the side-walls of the model and the soil within.
The study in hand considers experimental results to access the effect of boundary conditions and boundary roughness on the earth pressures and deformations in granular soils for at rest conditions in narrow models. Tests were performed under three different boundary conditions; Free-field conditions, conditions adjacent to structural boundary and condition of a narrow model replicating a centrifuge strong box. The study included multiple load-unload cycles that were performed at different soil densities and boundary roughnesses. A key characteristic of the study is the direct measurement of boundary soil pressures, in-soil pressure, in-soil strain and interface shear load. These measurements add credibility to the outcome and provide a better understanding of the kinematics of the soil and it response to varying boundary conditions in plane strain models. The results show a significant effect of the model dimensions and boundary roughness on the measured soil pressures and deformations. The description of the experimental set-up and measurement techniques follows. Finally the results are presented, discussed and compared to theoretical models.