Effect of Column-to Strength Ratio on the Performance of Code-Conforming Frame Buildings for 2023 Türkiye Earthquakes

Abstract

Seismic design regulations stipulate the strong-column-weak-beam approach to preclude column yielding during earthquakes. These codes also prescribe the minimums required to withstand seismic demands. However, it is possible to design structures beyond the minimum requirements. This study investigates how longitudinal reinforcement ratio limits influence column-to-beam flexural strength ratios (CBSR), examining the performance of frames with different CBSRs using ground motion records from the 2023 Turkiye earthquakes. Four frames were designed: two with the minimum and maximum possible reinforcement ratios at beams and columns, two with the minimum beam and maximum column reinforcement, and vice versa. The study reveals that the relative strength between the beams and columns significantly affects the extent and distribution of damage. When the beams are too weak compared to the columns, the damage intensifies. On the other hand, having a low overall strength also increases the damage potential. A crucial finding is that moment-frame systems, due to their relatively lower stiffness, faced high drift demands during the 2023 Turkiye earthquakes, leading to severe damage or collapse.