9:30 AM - 9:45 AM
[STT43-03] Verification toward ground motion calculation on the supercomputer Fugaku: Benchmark test on a model with topography and a basin (2)
Keywords:Earthquake ground motion simulation, Finite element method, Finite difference method, Benchmark test
In “Large-scale numerical simulation of earthquake generation, wave propagation and soil amplification”, one of the projects in the Program for Promotion Researches on the Supercomputer Fugaku, a large-scale finite element method (FEM) called E-wave FEM (Ichimura et al., 2009, 2014, 2015) have been developed to apply the method to earthquake ground motion simulation of a future giant subduction zone earthquake for a damage evaluation.
Earthquake ground motion simulation considering a complex 3D velocity structure is also useful for evaluating input ground motions for seismic design for high-rise and/or base-isolated structures with long natural periods. Currently, in most case a finite difference method (FDM) is used for such evaluation because of the simplicity of the method. On the other hand, an FEM has an advantage that it can precisely model a complex structural boundary including surface topography, but it is less frequently used because of the high computational cost and time-consuming mesh generation process. However, in addition to recent performance improvement of supercomputers, developments of fast calculation algorithm and automatic robust mesh generation tools (Ichimura et al., 2009, 2014, 2015) are compensating these shortcomings and utilizing the FEM for evaluating input ground motions for seismic design is expected.
Therefore, we have been performing verification of E-wave FEM and the FDM via benchmark tests. In our previous study (Kobayashi et al., 2022, JpGU), we performed a benchmark test on a simple structure model with surface topography and a sedimentary basin. In this study, we performed additional calculations using the same structure focusing on three factors as follows: an absorption region of the FEM, minimum mesh size of the FEM, and grid size of the FDM. In the presentation, we will also briefly report on a benchmark test on a realistic structure model with surface topography.
Acknowledgments: This work was supported by MEXT as “Program for Promoting Researches on the
Supercomputer Fugaku” (Large-scale numerical simulation of earthquake generation, wave propagation and soil amplification, Project ID: hp200126, hp210171, hp220171) and used computational resources of the Oakforest-PACS Supercomputer System provided by the Information Technology Center, The University of Tokyo and the Center for Computational Sciences, University of Tsukuba and the Earth Simulator provided by the Japan Agency for Marine-Earth Science and Technology. This work used the E-wave FEM code which was originally provided by the Earthquake Research Institute, The University of Tokyo and modified by JAMSTEC.
Earthquake ground motion simulation considering a complex 3D velocity structure is also useful for evaluating input ground motions for seismic design for high-rise and/or base-isolated structures with long natural periods. Currently, in most case a finite difference method (FDM) is used for such evaluation because of the simplicity of the method. On the other hand, an FEM has an advantage that it can precisely model a complex structural boundary including surface topography, but it is less frequently used because of the high computational cost and time-consuming mesh generation process. However, in addition to recent performance improvement of supercomputers, developments of fast calculation algorithm and automatic robust mesh generation tools (Ichimura et al., 2009, 2014, 2015) are compensating these shortcomings and utilizing the FEM for evaluating input ground motions for seismic design is expected.
Therefore, we have been performing verification of E-wave FEM and the FDM via benchmark tests. In our previous study (Kobayashi et al., 2022, JpGU), we performed a benchmark test on a simple structure model with surface topography and a sedimentary basin. In this study, we performed additional calculations using the same structure focusing on three factors as follows: an absorption region of the FEM, minimum mesh size of the FEM, and grid size of the FDM. In the presentation, we will also briefly report on a benchmark test on a realistic structure model with surface topography.
Acknowledgments: This work was supported by MEXT as “Program for Promoting Researches on the
Supercomputer Fugaku” (Large-scale numerical simulation of earthquake generation, wave propagation and soil amplification, Project ID: hp200126, hp210171, hp220171) and used computational resources of the Oakforest-PACS Supercomputer System provided by the Information Technology Center, The University of Tokyo and the Center for Computational Sciences, University of Tsukuba and the Earth Simulator provided by the Japan Agency for Marine-Earth Science and Technology. This work used the E-wave FEM code which was originally provided by the Earthquake Research Institute, The University of Tokyo and modified by JAMSTEC.