Performance of base-isolated moment resisting steel frames subjected to pounding effects under near-field earthquake ground motions
Despite conservative requirements of existing building code regarding clear seismic gap distance of base-isolated (BI) structures to surrounding moat walls, seismic performance of these structures is still ambiguous under severe earthquake ground motions that may push the base slab of the isolation...
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Iranian Society of Structrual Engineering (ISSE)
2021
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oai:doaj.org-article:fb3cebd9ac7d4664bf9e9c825ae01d8a2021-11-08T15:54:39ZPerformance of base-isolated moment resisting steel frames subjected to pounding effects under near-field earthquake ground motions2476-39772538-261610.22065/jsce.2019.190572.1887https://doaj.org/article/fb3cebd9ac7d4664bf9e9c825ae01d8a2021-05-01T00:00:00Zhttps://www.jsce.ir/article_91105_2424518dfd972ea39aebc8283a6c074c.pdfhttps://doaj.org/toc/2476-3977https://doaj.org/toc/2538-2616Despite conservative requirements of existing building code regarding clear seismic gap distance of base-isolated (BI) structures to surrounding moat walls, seismic performance of these structures is still ambiguous under severe earthquake ground motions that may push the base slab of the isolation system to collide to the surrounding moat walls. Moreover, the temptation of reducing seismic gaps in congested urban areas exacerbates the risk of pounding. Excessive horizontal displacement response of these long-period structures subjected to a rare near-field ground motion may lead to pounding to adjacent structures and subsequently, severe and uncontrolled damage or even total collapse of the superstructure.Pounding of BI structures to moat walls is usually considered as an unwanted response that may inflict critical damage to a high importance structure designed for high performance levels. Pounding effects to the moat walls depend on several parameters including superstructure and isolated periods, damping, seismic gap as well as characteristics of the earthquake ground motion. This study aims to evaluate seismic response of base-isolated moment resisting steel frames subjected to pounding effects under near-field earthquake ground motions with different clear gap distances to surrounding moat walls. A seven story and a three story buildings isolated with elastomeric bearings have been modeled. Base slab displacement, global displacement ductility demands, yield strength reduction factors, and maximum inter-story drifts have been computed under recorded severe near-field earthquake ground motions. Results showed that for most of the seismic gaps lower than those of prescribed by codes, seismic demands remain in acceptable ranges corresponding to low performance levels, i.e., life safety or collapse prevention of fixed-base structures. This implies that performance of BI buildings with codified seismic gaps or insufficient seismic gaps is not much different than that of fixed-base buildings when they are pushed to their displacement limits under maximum considered earthquakes.Mona GhalehnoyMostafa MasoudiIranian Society of Structrual Engineering (ISSE)articleseismic isolationpoundingnear-field ground motionsteel moment resisting frameseismic gapseismic performanceBridge engineeringTG1-470Building constructionTH1-9745FAJournal of Structural and Construction Engineering, Vol 8, Iss 3, Pp 266-280 (2021) |
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seismic isolation pounding near-field ground motion steel moment resisting frame seismic gap seismic performance Bridge engineering TG1-470 Building construction TH1-9745 |
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seismic isolation pounding near-field ground motion steel moment resisting frame seismic gap seismic performance Bridge engineering TG1-470 Building construction TH1-9745 Mona Ghalehnoy Mostafa Masoudi Performance of base-isolated moment resisting steel frames subjected to pounding effects under near-field earthquake ground motions |
description |
Despite conservative requirements of existing building code regarding clear seismic gap distance of base-isolated (BI) structures to surrounding moat walls, seismic performance of these structures is still ambiguous under severe earthquake ground motions that may push the base slab of the isolation system to collide to the surrounding moat walls. Moreover, the temptation of reducing seismic gaps in congested urban areas exacerbates the risk of pounding. Excessive horizontal displacement response of these long-period structures subjected to a rare near-field ground motion may lead to pounding to adjacent structures and subsequently, severe and uncontrolled damage or even total collapse of the superstructure.Pounding of BI structures to moat walls is usually considered as an unwanted response that may inflict critical damage to a high importance structure designed for high performance levels. Pounding effects to the moat walls depend on several parameters including superstructure and isolated periods, damping, seismic gap as well as characteristics of the earthquake ground motion. This study aims to evaluate seismic response of base-isolated moment resisting steel frames subjected to pounding effects under near-field earthquake ground motions with different clear gap distances to surrounding moat walls. A seven story and a three story buildings isolated with elastomeric bearings have been modeled. Base slab displacement, global displacement ductility demands, yield strength reduction factors, and maximum inter-story drifts have been computed under recorded severe near-field earthquake ground motions. Results showed that for most of the seismic gaps lower than those of prescribed by codes, seismic demands remain in acceptable ranges corresponding to low performance levels, i.e., life safety or collapse prevention of fixed-base structures. This implies that performance of BI buildings with codified seismic gaps or insufficient seismic gaps is not much different than that of fixed-base buildings when they are pushed to their displacement limits under maximum considered earthquakes. |
format |
article |
author |
Mona Ghalehnoy Mostafa Masoudi |
author_facet |
Mona Ghalehnoy Mostafa Masoudi |
author_sort |
Mona Ghalehnoy |
title |
Performance of base-isolated moment resisting steel frames subjected to pounding effects under near-field earthquake ground motions |
title_short |
Performance of base-isolated moment resisting steel frames subjected to pounding effects under near-field earthquake ground motions |
title_full |
Performance of base-isolated moment resisting steel frames subjected to pounding effects under near-field earthquake ground motions |
title_fullStr |
Performance of base-isolated moment resisting steel frames subjected to pounding effects under near-field earthquake ground motions |
title_full_unstemmed |
Performance of base-isolated moment resisting steel frames subjected to pounding effects under near-field earthquake ground motions |
title_sort |
performance of base-isolated moment resisting steel frames subjected to pounding effects under near-field earthquake ground motions |
publisher |
Iranian Society of Structrual Engineering (ISSE) |
publishDate |
2021 |
url |
https://doaj.org/article/fb3cebd9ac7d4664bf9e9c825ae01d8a |
work_keys_str_mv |
AT monaghalehnoy performanceofbaseisolatedmomentresistingsteelframessubjectedtopoundingeffectsundernearfieldearthquakegroundmotions AT mostafamasoudi performanceofbaseisolatedmomentresistingsteelframessubjectedtopoundingeffectsundernearfieldearthquakegroundmotions |
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