Validation of Simulated Earthquake Ground Motions for Displacement Response of Building and Bridge Structures Based on Intensity and Frequency Content Parameters

Abstract

This paper introduces a statistical methodology, titled vector-based intensity-measure method (VBIM), to validate simulated ground motions for the estimation of structural response parameters and demonstrate its application using case study structures. VBIM combines several intensity measures representative of key ground motion waveform components that affect structural response—including intensity and frequency content parameters—to validate simulated ground motions. Because the validation and the use of simulated ground motions are of interest to engineers and ground motion simulators, the selected waveform parameters used as validation metrics provide easily interpretable proxies for multiple stakeholders. Four time-dependent metrics are considered to assess how the differences in these parameters correlate to the differences in structural response between simulated and recorded ground motions. The study used 2- and 12-story special steel moment-resisting frame (SMRF) buildings and a two-span, cast-in-place concrete bridge as case study structures to showcase the application of VBIM. Results indicate that models of simulated and recorded ground motions that predict structural response based on waveform parameters are similar. Furthermore, Arias intensity is the most significant waveform parameter predicting response for all three case study structures. The difference in Arias intensity between recorded and simulated ground motions strongly correlates to differences in bridge response. The results of this study provide recommendations for ground motion simulators regarding the required accuracy of these key parameters for simulated ground motions to accurately predict structural response while also providing several steps of validation that show similarities between recorded and simulated ground motions.