Co-Investigator(Kenkyū-buntansha) |
TAMURA Takeshi Kyoto University, Faculty of Engineering, Department of Civil Engineering, Professor, 大学院・工学研究科, 教授 (30026330)
ASAOKA Akira Nagoya University, Faculty of Engineering, Department of Civil Engineering, Professor, 大学院・工学研究科, 教授 (50093175)
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Research Abstract |
1) Bifurcation Analysis in a Circular Cylinder of Coaxial and Non-coaxial Cam-clay Models. We obtain the exact solutions for all diffuse modes under symmetric and anti-symmetric deformation for coaxial and non-coaxial Cam-clay model., We find that, for a non-coaxial model, the bifurcation loads for all modes exist and nearly equal for a compressive test; however, the load for an extended test takes its minimum in a - constriction mode. These results agree well with the experimental deformation pattern of saturated clays. We then find that for a non-coaxial model, judging from the distributions of the maximum strain, the predicted net-like slip planes agree well with the observed slip pattern in the compressive test of clays. We find also, for a coaxial model, the bifurcation load for an ax symmetric bulging mode, which is often observed in the experiments, does not exist. This shows that the non-coaxial terms are indispensable to investigate the landslip. 2) Finite Element Method Analysis of Soil/Water Couping Problems using an Implicit Calculation Algorithm. We develop a new method of implicit, finite element analysis of soil / water coupling problems in a well-known Cam-clay model. The implicit return mapping scheme is based on the elastic predictor and the plastic corrector. Some examples of the implicit method show the high accuracy and much reducing the total CPU time. 3) Finite Element Analysis with the Incompatible Elements and the Examination of the Accuracy. As a basic research on the landslip, we developed a strong discontinuity finite element analysis with the displacement discontinuity inside the elements, which solutions are mesh-independent. We then estimate the method by means of verifying the accuracy of the fracture energy by using the E-integral. As a result, we find that the strong discontinuity analysis is high accurate in view of the fracture energy.
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