Document Type : Structural Earthquake Engineering
International Institute of Earthquake Engineering and Seismology (IIEES)
Detecting the buildings experiencing collapse against future earthquakes is the most vital for seismic urban areas in Iran because of its irreparable consequences. Once again, the occurrence of Sarpol-e Zahab Earthquake (Mw=7.3) reminded us of this necessity where structural collapses resulted in a large number of casualties. A simplified methodology is developed to assess the collapse of mid-rise concrete buildings during earthquakes in Iran. Besides, an attempt is made to verify this method through analyzing the recorded data of the collapsed buildings suffered from Sarpol-e Zahab earthquake of November 12, 2017, and considers whether the occurrence of the collapse could be anticipated or not. Three severely damaged buildings were selected, located in Sarpol-e Zahab, to verify this proposed methodology. They are 2 or 3 story buildings having moment resisting frames. The buildings are analyzed through nonlinear analysis. The well-calibrated nonlinear model is adopted for the nonlinear analysis. The intensity of damages are observed and recorded by the authors. The pushover analysis is conducted for them. Drifts evaluated by pushover analysis are compared to those recorded in the buildings. One of the buildings was a bare frame that its partitions and infill walls are not still constructed. This building had much better performance than two others and experienced less loss. Moreover, the results of the analysis show that the collapse criteria related to the seismic evaluation codes are non-conservative. The results of this survey imply that the proposed method can precisely forecast the collapse or non-collapse of the studied buildings. Therefore, it would be recognized as a reliable method for collapse assessment.