Performance Seismic Assessment of Steel Frame Structures Having Torsional Irregularity Subjected to Mainshock-Aftershock

Document Type : Original Article

Authors

1 Master Student of Structural Engineering, Shahrood University of Technology, Sharood, Iran

2 Assistant Professor, School of Civil Engineering, Shahrood University of Technology, Shahrood, Iran

3 Assistant Professor, School of Civil Engineering, Shahrood University of Technology, Sharood, Iran

Abstract

The earthquake is a phenomenon that is likely to occur all over the world and so far it has caused a lot of human and financial losses. During earthquake events, it is not uncommon to observe after-shocks following a mainshock, aftershocks have the potential to cause severe damage to buildings and threaten life safety even when only minor damage is present from the mainshock, but in the current regulations, the effect of aftershocks is not considered.
Another factor affecting the behavior of the building during the earthquake is a torsional irregularity that may be due to architectural constraints in the building and, if accompanied by aftershock, results in further damage to the structure.
In this article, for assessing the effects of torsional irregularity and also the aftershocks, 3,5 and 8 story models with steel moment frame seismic system, first regular in plan and then with torsional irregularity are carried out according to the Iranian seismic code and then 3-dimensional analytical models analyzed based on Incremental Dynamic Analysis (IDA) in OpenSees. The maximum inter-story drift ratio is obtained for 20 sets of ground motion records with aftershocks compatible with the conditions of the region and the capacity is determined according to HAZUS-MH limit states and finally, the corresponding fragility curves for seismic performance levels of slight, moderate, extensive and complete are developed.
The resulting seismic fragility curves revealed the destructive effect of torsional irregularity in 5 and 8 story is more than 3 story and the aftershock outputs illustrated that the effect of aftershock on the damage level increase when building have torsional irregularity.

Keywords

Main Subjects

References

[1]  Zhai, C.; Wen, W.; Chen, Z.; Li, S. and Xie, L. (2013), "Damage spectra for the mainshock–aftershock sequence-type ground motions", Soil Dynamics and Earthquake Engineering, vol. 45, no. Supplement C, pp. 1-12
[2]  Yeo, G. L. and Cornell, C. A. (2005), "Stochastic characterization and decision bases under time-dependent aftershock risk in performancebased earthquake engineering", Rep. No. TB 149, The John A. Blume Earthquake Engineering Center, Stanford Univ., Stanford, CA.
[3]  Ibarra, F.; Krawinkler, and Helmut, (2005)," Global Collapse of Frame Structures Under Seismic Excitations"
[4]  Li, Q. and Ellingwood, B. (2007), " Performance evaluation and damage assessment of steel frame buildings under main shock-aftershock sequences", pp. 405-427.
[5]  Lindt, J. (2008), "Experimental Investigation of the Effect of Multiple Earthquakes on Woodframe Structural Integrity".
[6]  Li, Y.; Yin ,Y.; Ellingwood, B. and Bulleit, W. (2010), "Uniform hazard versus uniform risk bases for performance‐based earthquake engineering of light‐frame wood construction", pp. 1199-1217.
[7]  Reasenberg, P. A. and Jones, L. M. (1994), "earthquake aftershocks: update", Science, vol. 265, Issue 5176, pp. 1251-1252.
[8]  Pei, S. and Lindt, J. (2009), " Methodology for earthquake-induced loss estimation: An application to woodframe buildings", pp. 31-42.
[9]  Naseri, A.; Pahlavan, H. and Ghodrati Amiri G. (2017), "Probabilistic seismic assessment of RC frame structures in North of Iran using fragility curves", Journal of Structural and Construction Engineering (JSCE).
[10]        Silwal, B. and Ozbulut, O. (2018), "Aftershock fragility assessment of steel moment frames with self-centering dampers", Engineering Structures, vol. 168, pp. 12-22.
[11]        MRl, H. (2003), "Multi-hazard loss estimation methodology: Earthquake model", Department of Homeland Security, FEMA, Washington, DC.
[12]        Li,Y.; Song, R. and Van De Lindt, W. (2014), "Collapse Fragility of Steel Structures Subjected to Earthquake Mainshock-Aftershock Sequences", Journal of Structural Engineering, vol. 140, no. 12, p. 04014095.
[13]        Krawinkler and Whittaker, (2007), "Sidesway Collapse of Deteriorating Structural Systems Under Seismic Excitation", NEES Inc.
[14]        Jalali, S.; Banazadeh, M.; Abolmaali, A. and Tafakori, E. (2012), "Probabilistic seismic demand assessment of steel moment frames with side-plate connections", Scientia Iranica, vol. 19, no. 1, pp. 27-40,
Journal of Structural and Construction Engineering
Volume 8, Issue 8 - Serial Number 47
November 2021
Pages 249-265

Files

History

  • Receive Date: 25 April 2019
  • Revise Date: 16 September 2020
  • Accept Date: 04 October 2020

Share

How to cite

Statistics