Investigation of seismic collapse performance of RC frames with strengthened masonry infill walls under February 6, 2023 earthquakes in Türkiye

Two destructive earthquakes on February 6, 2023, in Türkiye, have demonstrated the importance of seismic retrofitting of those structures with weak seismic performance since many reinforced concrete (RC) structures have collapsed or experienced heavy damage. Many structures are seriously damaged in eleven different provinces. According to authorities, almost 250,000 structures suffered severe damage or were destroyed, more than 50,000 people lost their lives, and more than 100,000 people were injured. These two major earthquakes have once again highlighted the need to strengthen RC structures with inadequate seismic performance before or retrofit after earthquakes. Adding a reinforced stucco layer to the masonry infill walls is a preferred, easy-to-apply, cost-effective and less labor-intensive method for strengthening RC frame structures. This study investigates the effect of a masonry infill walls strengthening method for reinforced concrete structural frames and the purpose of the work is to show seismic performance enhancement with the strengthening method. The behavior of three different models is simulated, and seismic performance is observed for classical and strengthened infill walls. Incremental dynamic analysis procedure is applied with earthquake motions from February 6, 2023 events in Türkiye. Earthquake simulation program OpenSees is used for the time history analysis in this study. Results indicate that strengthening infill walls by adding a rebar layer with mortar can enhance buildings’ seismic performance. Also, the seismic collapse probabilities of frames within fifty years are evaluated, and the results of strengthened infill walls are compared with the classical walls. Results indicate that strengthening method can reduce collapse probability of frames in fifty years around 30% depending on structural properties.