Advanced computational geomechanics for analysis of earth structures

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The future of modeling in Geotechnical [Earthquake] Engineering will be all about Performance-Based Design, PBD, essentially displacement based for earth structures. PBD and the evaluation of post-yield behavior require a paradigm shift toward a displacement or deformation-based design, as opposed to the traditional force-based design that has been applied to soil mechanics and foundation engineering problems. A realistic 3D simulation of the nonlinear material subjected to irregular earthquake loading is very complex. For this purpose, one needs advanced and efficient computational tools. Such tools need to handle a number of key modeling points in geotechnical engineering such as transient loading, fully coupled solid-fluid interaction for realistic generation and dissipation of excess pore pressure, three-dimensional analyses, inclusion of structural elements, and constitutive behavior of the soil matrix, which is the crucial part of a successful numerical simulation. The long-term aim of the present proposal is to bring the modeling to the next level, and to provide newer and more accurate means of analysis to the research and engineering communities. The focus here will be given to advanced constitutive modeling of sands and clays in seismic loading, and numerical simulation in 3D framework. The proposed research outcome would generate two novel constitutive models for numerical simulation of cyclic loading in geomaterials. These constitutive models will be efficient and rigorous, yet simple and user friendly from the perspective of calibration and interpretation of results. The newly developed models will be efficiently integrated into the FLAC3D computational framework, which will extend their applicability in the advanced research community and design practice. An extensive verification and validation will be conducted using the experimental data available at UBC, NGI, NEES and C-Core. Finally, on application of the developed tools, among many relevant problems, focus will be given to analysis of soil-pile interaction problems, study on ocean floor stability in structured clays under seismic events, and underlying issues in 3D characterization of dams.