Assessment of Seismic Demands caused by 12 November 2017 Ezgeleh Earthquake (Mw=7.3) in Kermanshah

Document Type : Research Article

Authors

1 Ministry of Roads &Urban Development, Kermanshah,Iran

2 Department of Civil Engineering, Razi University, Kermanshah, Iran

Abstract

A severe earthquake ground motion with a moment magnitude of Mw=7.3 took place in the western part of Iran on 12 November 2017. The main objective of this study is to evaluate the seismic demands of structures under the recent November 12, 2017, Ezgeleh (Mw=7.3) earthquake. For this purpose, we selected the ground motions recorded at Sarpol-e-Zahab, Goorsefid, Kerend, and Javanrood stations that have maximum PGA. Evaluation is conducted by generalized inter-story drift spectra, input energy spectra, ductility demands (μ) and the spectra computed for selected records. Also, the time evolution of the frequency-intensity content of selected records is discussed based on the Wavelet Transform (WT). Time-frequency analysis of ground-motions recorded at the Sarpol-e Zahab station shows that there is a transition of energy content of E-W component with lower periods (i.e. 0.25 sec) to moderate periods (i.e.0.50,0.75 sec ). There is a potential for moving resonance in buildings with short periods between (0.2-0.5 sec). Also, it can be observed that most energies of the N-S component were highly concentrated at a long period band (between 0.9 and 1.5 sec) that is considered as pulse-like. These findings are consistent with the damage observed in Sarpol-e-Zahab and its villages, where many dwellings and buildings collapsed or suffered severe damage during this event have a low fundamental period between )0.2 and 0.5 sec).

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