LESSONS LEARNED FROM DAMAGE OF REINFORCED CONCRETE BUILDINGS IN THE 2023 TÜRKIYE-SYRIA EARTHQUAKE

The 2023 Türkiye-Syria Earthquake caused extensive damage to reinforced concrete buildings. The AIJ Earthquake Disaster Reconnaissance Team extensively surveyed reinforced concrete buildings in the affected areas and collected damage data on more than 20 buildings in order to clarify the characteristics of earthquake damage to reinforced concrete buildings with Turkish researchers. In most of the damaged reinforced concrete buildings, it was found that the damage was caused by the structural characteristics made by the design and construction. On the other hand, there were many similarities with the damages observed in past earthquakes in Japan. Analyzing these common damages and confirming their causes and countermeasures will be useful for future earthquake damage mitigation of reinforced concrete buildings. The purpose of this study is to compare the earthquake damage observed in this earthquake with past earthquake damage in Japan, discuss its causes, and clarify methods and countermeasures for designing/ constructing reinforced concrete buildings with higher earthquake resistance and safety. From the damage investigation, it was concluded that most of the damage to the reinforced concrete building was caused by crushing of concrete at the base of the wall column on the first floor, buckling of longitudinal bars, fracture of reinforcing bars and lack of transverse reinforcing bars, failure of joints due to splitting of main beam bars. In addition, damage due to interaction with the ground response was observed. In terms of the collapse mechanism, a total collapse mechanism with plastic hinges formed at the beam ends was also confirmed, and the validity of the design method was also confirmed; however, it should be noted that insufficient ductility of the base of the wall column at the first floor and the beam ends, as mentioned above, may lead to the collapse of the building. In recent years, there has been increasing interest in the repairability and continued use of buildings after earthquakes. Based on the above analysis, this study presents the reinforcement and cross-section design required to achieve buildings with excellent long-term serviceability, and offers suggestions for design methods.