Predictive Simulation for Surface Fault Occurrence Using High-Performance Computing

Masataka Sawada,Muneo Hori,Kazumoto Haba

doi:10.3390/geohazards3010005

Abstract

Numerical simulations based on continuum mechanics are promising methods for the estimation of surface fault displacements. We developed a parallel finite element method program to perform such simulations and applied the program to reproduce the 2016 Kumamoto earthquake, where surface rupture was observed. We constructed an analysis model of the 5 × 5 × 1 km domain, including primary and secondary faults, and inputted the slip distribution of the primary fault, which was obtained through inversion analysis and the elastic theory of dislocation. The simulated slips on the surface were in good agreement with the observations. We then conducted a predictive simulation by inputting the slip distributions of the primary fault, which were determined using a strong ground motion prediction method for an earthquake with a specified source fault. In this simulation, no surface slip was induced in the sub-faults. A large surface slip area must be established near a sub-fault to induce the occurrence of a slip on the surface.

Highlights

Since the occurrence of massive earthquakes in Taiwan and Turkey in 1999, there have been growing concerns regarding potential damage to various infrastructure systems and buildings caused by surface fault ruptures
In case3, only the main fault slips before twice the value of Db is inputted, despite the fact that twice the value of Da was inputted in the asperities
We developed a parallel finite element method (FEM) program to estimate surface fault displacement

Summary

Introduction

Since the occurrence of massive earthquakes in Taiwan and Turkey in 1999, there have been growing concerns regarding potential damage to various infrastructure systems and buildings caused by surface fault ruptures. Numerical simulations based on continuum mechanics are promising evaluation methods for the estimation of surface fault displacements. The following two-step simulation method is adopted [1]: (1) evaluating the boundary displacement of an area containing a target facility by determining the crustal deformation based on the elastic theory of dislocation [2] and (2) evaluating the deformation of the target area using a detailed two-dimensional model with high resolution and fidelity. It was difficult to conduct dynamic rupture simulations at a sufficiently high resolution because it requires a large amount of computation resources. Fault displacement analyses using dynamic rupture simulation with high-resolution detailed analytical models have begun to be reported [8,9,10,11]

Objectives

Methods

Results

Discussion

Conclusion