Performance of RC Structures and Associated Lessons to be Learned from November 12, 2017, Sarpol-e Zahab - Ezgeleh Earthquake (MW 7.3)

Sarpol-e Zahab - Ezgeleh earthquake (MW 7.3) occurred in Iran and Iraq border region on November 12, 2017 at 21:48 local time. This earthquake is the most devastating event in Iran after the 2003 Bam earthquake (MW 6.6) in terms of damages. According to findings arising from the visit to the earthquake affected area between November 25 and 30, 2017, heavy structural and non-structural damages were occurred in all types of RC buildings, including structures built in national Iranian mass housing project, called Mehr housing scheme. In many cases, new structures, experienced severe damages or collapse during the earthquake, even in regions with low recorded PGA like Sharafabad town in Eslamabad-e Gharb city. Post-earthquake studies showed that damages in RC structures were mostly due to the poor construction quality including low concrete strength and nonseismic detailing as well as false structural design and local site effects. According to Iran construction laws, the Iran Construction Engineering Organization (IRCEO) is the prime responsible for the effective supervision in structural design and construction process in urban areas. Considerable number of damaged buildings that are constructed in recent years, is probably because of the lack of enough supervision by IRCEO and other responsible organizations. In this paper, observed damages to RC structures were examined and explained in detail.