Sensitivity of the Fragility Curve on Type of Analysis Methods, Applied Ground Motions and Their Selection Techniques

Samreen Fatimah,Jenna Wong

doi:10.1007/s13296-021-00503-z

Samreen Fatimah, Jenna Wong

https://doi.org/10.1007/s13296-021-00503-z

Copy DOI

Abstract

Fragility curves are the primary way of assessing seismic risk for a building with numerous studies focused on deriving these fragility curves and how to account for the inherent uncertainty in the seismic assessment. This study focuses on a three-story steel moment frame structure and performs a fragility assessment of the building using a new approach called SPO2FRAG (Static Pushover to Fragility) that is based on pushover analysis. This new approach is further compared and contrasted against traditional nonlinear dynamic analysis approaches like Incremental Dynamic Analysis and Multiple Stripe Analysis. The sensitivity of the resulting fragility curves is studied against multiple parameters including uncertainties in ground motion, the type of analysis method used and the choice of curve fitting technique. All these factors influence the fragility curve behavior and this study assesses the impact of changing these parameters.

Highlights

Building collapse during an earthquake can lead to significant numbers of casualties and injuries
Comprehensive fragility assessment of structural collapse requires a robust analytical model showing nonlinear behavior and an explicit consideration of the uncertainty in ground motion. This type of analysis method has inherent uncertainties due to the manner in which structural simulations are conducted and the curve fitting technique used to create the fragility curves
The aim of this study is to examine the collapse failure probability of a steel moment frame derived using several approaches including: incremental dynamic analysis (IDA), multiple strip analysis (MSA), and a new method called SPO2FRAG

Summary

Introduction

Building collapse during an earthquake can lead to significant numbers of casualties and injuries. Comprehensive fragility assessment of structural collapse requires a robust analytical model showing nonlinear behavior and an explicit consideration of the uncertainty in ground motion This type of analysis method has inherent uncertainties due to the manner in which structural simulations are conducted (resulting in the key structural responses needed for assessment) and the curve fitting technique used to create the fragility curves. In order to do a comprehensive fragility assessment of a structure for seismic risk under different damage states, researchers have studied this subject from multiple approaches They have compared different dynamic analysis methods as well as different suites of ground motions and their impact on structural response. In the study the results of IDA are compared against other approaches to evaluate the fragility curve accuracy

Objectives

Methods

Results

Conclusion