Integrated earthquake simulation (IES) is a seamless simulation of analyzing all processes of earthquake hazard and disaster. There are two difficulties in carrying out IES, namely, the requirement of large-scale computation and the requirement of numerous analysis models for structures in an urban area, and they are solved by taking advantage of high performance computing (HPC) and by developing a system of automated model construction. HPC is a key element in developing IES, as it needs to analyze wave propagation and amplification processes in an underground structure; a model of high fidelity for the underground structure exceeds a degree-of-freedom larger than 100 billion. Examples of IES for Tokyo Metropolis are presented; the numerical computation is made by using K computer, the supercomputer of Japan. The estimation of earthquake hazard and disaster for a given earthquake scenario is made by the ground motion simulation and the urban area seismic response simulation, respectively, for the target area of 10,000 m × 10,000 m.

Damage to buried pipelines caused by local amplification of seismic ground motion in highly nonuniform grounds is not yet fully understood. The development of methods to evaluate the amplification of ground motion in complex ground structures is thus desirable. Here, we report large-scale nonlinear seismic ground response analysis using a 3D nonlinear finite element method (FEM) and attempt to reproduce observed seismic ground motion. We also discuss the strain amplification processes and their effects on buried pipelines in detail. The findings are expected to aid in improving the seismic resistance of buried pipelines.

The parallel scalability of the seismic response analysis (SRA) module of the Integrated Earthquake Simulator (IES) is enhanced to achieve near-ideal scalability. In previous studies, the SRA module was enhanced with standard distributed memory parallel computing techniques. However, some bottlenecks seriously hinder its scalability. Parallel computing performance is significantly improved by eradicating all the bottlenecks; input/output modules are enhanced with advanced MPI functions, a static load balancer is introduced, and the link to seismic structure analysis programs is strengthened. Details of the bottlenecks, remedies implemented, and other performance enhancements are presented. With a moderate size problem, it is demonstrated that the modified SRA module has near-ideal scalability. Further, it is shown that this near-ideal scalability is sustained even in the simulation of a large urban area.