Physics-Based Urban Earthquake Simulation Enhanced by 10.7 BlnDOF × 30 K Time-Step Unstructured FE Non-Linear Seismic Wave Simulation

With the aim of dramatically improving the reliability of urban earthquake response analyses, we developed an unstructured 3-D finite-element-based MPI-OpenMP hybrid seismic wave amplification simulation code, GAMERA. On the K computer, GAMERA was able to achieve a size-up efficiency of 87.1% up to the full K computer. Next, we applied GAMERA to a physics-based urban earthquake response analysis for Tokyo. Using 294,912 CPU cores of the K computer for 11 h, 32 min, we analyzed the 3-D non-linear ground motion of a 10.7 BlnDOF problem with 30 K time steps. Finally, we analyzed the stochastic response of 13,275 building structures in the domain considering uncertainty in structural parameters using 3 h, 56 min of 80,000 CPU cores of the K computer. Although a large amount of computer resources is needed presently, such analyses can change the quality of disaster estimations and are expected to become standard in the future. Keywords—Time-to-solution, scalability, urban earthquake simulation, unstructured FEM