A new proxy for ground motion selection in seismic collapse assessment of tall buildings |
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Authors: | Masood Yakhchalian Gholamreza Ghodrati Amiri Ahmad Nicknam |
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Affiliation: | 1. School of Civil Engineering, Iran University of Science & Technology, , Tehran, Iran;2. Center of Excellence for Fundamental Studies in Structural Engineering, School of Civil Engineering, Iran University of Science & Technology, , Tehran, Iran |
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Abstract: | Tall buildings are long‐period structures that are sensitive to the long‐period content of ground motions. Selection of appropriate ground motions is an important step in seismic collapse assessment of tall buildings using nonlinear dynamic analyses. Epsilon (εSa) and eta (η) are two spectral shape indicators, which have been recently proposed for ground motion selection in the technical literature. In this study, a new parameter gamma (γ) is proposed, which has considerable correlation with the collapse capacity of long‐period structures having a fundamental period greater than 1 s. This parameter is a linear combination of εSa and the displacement spectrum intensity epsilon (εDSI). The parameter γ is obtained and optimized by applying the particle swarm optimization algorithm. Since γ has significant correlation with the collapse capacity of long‐period structures, it can be used as an efficient proxy for ground motion selection in seismic collapse assessment of tall buildings. The results of this study show that ground motion selection considering the new proxy γ causes reduction in the dispersion of structural response and also decrease in the mean annual frequency of collapse, when compared with ground motion selection based on εSa and η. Copyright © 2013 John Wiley & Sons, Ltd. |
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Keywords: | tall building ground motion selection epsilon gamma seismic collapse assessment mean annual frequency of collapse |
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