High performance computational geomechanics and its application on soil-structure-interaction problems

This PhD dissertation presents the development of the Plastic Domain Decomposition (PDD) algorithm, which features adaptive dynamic load balancing operations for nonlinear finite element simulations. This algorithm has been implemented within the OpenSees (Open System for Earthquake Engineering Simulation) framework. Performance study on SFSI (Soil Foundation Structure Interaction) analyses indicates the efficiency of the proposed algorithm. Large scale prototype SSI (Soil Structure Interaction) analyses have been performed using the developed software package. Results are presented and discussed.; The first part of the PhD dissertation introduces the theoretical background of the proposed PDD algorithm. Multi-objective and multi-constraint graph partitioning algorithms lay the foundation of the algorithm building. Parametric study has been conducted to tune the partitioning kernel for our specific application codes. The algorithm is implemented following Object-Oriented principle within the OpenSees framework. Design details are presented. Major class abstraction and related member functions are summarized. Interfaces to external libraries are also introduced. Comprehensive performance study on SFSI models has been conducted. A novel application cost model is proposed to deal with implementation-dependent overheads. Comparison of proposed PDD algorithm to classic Domain Decomposition (DD) shows significant performance gains for inelastic finite element simulations.; The second part of the PhD dissertation is devoted to the issue of parallel equation solving in large scale finite element simulations. The efficiency of projection-based iterative solvers and some popular direct solvers is investigated using equation systems extracted from SFSI simulations. Complete parallel implementation has been developed within OpenSees using the consistent PETSc interface.; The third part of the PhD dissertation handles large scale real world SSI simulations using the parallel finite element software developed in this PhD dissertation. New 3D modeling techniques have been proposed to enable the seamless usage of both nonlinear structural and geotechnical theories in a single 3D prototype model. The multi-stage construction sequence simulation is developed to accurately simulate preexisting in situ stress state of soil. These finite element modeling skills are applied thoroughly in NEES simulations, which include centrifuge experiment simulations and prototype 4 span bridge SFSI system simulations. Finally, the results are discussed and conclusions are presented.