Deterministic Large-Scale Wavefield Simulations Carried Out at Service Hall Array and Their Validation Using Nga-West2 Suit of GMPEs

Session: Numerical Modeling of Rupture Dynamics, Earthquake Ground Motion and Seismic Noise [Poster]
Type: Poster
Date: 4/29/2020
Time: 08:00 AM
Room: Ballroom
Description: 

As the research community moves forward with Risk-Informed-Performance-Based-Design philosophy, it is evident that we need ground motion simulations that correlate well with observed ground motions, to improve the risk analysis of structures. The advent of superlative computational infrastructure has made it possible to perform intensive calculations to solve physics-based wave propagation equations (Rodgers et al., 2019). This research will utilize a finite difference code, SW4, developed by Lawrence Livermore National Laboratory, to simulate an Mj= 4.2 aftershock event of the 2007 Niigata-Chuetsu earthquake.

The seismic event is chosen for its low magnitude which permits a simple source model, and its proximity (4 km) to our site of interest- the widely studied Service Hall Array (SHA) at Kashiwazaki-Kariwa Nuclear Power Plant (KKNPP) in Japan. A computational domain of 7 x 30 km², combined with a structured mesh refinement option in SW4, allows us to resolve up to 3 Hz maximum frequency, utilizing even the lowest velocity of 130 m/s at the surface. A 1D material model will be applied to the 3D computational model. The material properties are derived from a combination of geotechnical investigations carried out at SHA and two community velocity models- Japan Integrated Velocity Model and Japan Seismic Hazard Information Station.

Spatial attenuation of both horizontal and vertical ground motion simulations will be validated against a suit of Ground Motion Prediction Equations developed as part of the NGA-West2 project. These GMPEs employ an extensive dataset to identify empirical attenuation relations based on the magnitude of the source, path effects and soil properties at the site. The availability of adjustment factors specific to the geology of Japan make them good candidates for this study. Finally, residuals between simulations and these GMPEs will be identified and discussed.

Presenting Author: Swasti Saxena

Authors