Assessment of the Seismic Performance of a TBEC 2018-Compliant Chevron-Braced Steel Building under Pulse-Like and Non-Pulse-Like Ground Motions

The devastating earthquake sequence that struck southern Türkiye on February 6, 2023, consisted of two major events with moment magnitudes of Mw 7.7 and Mw 7.6, affecting 11 provinces and resulting in extensive loss of life and severe damage to the built environment. Following the earthquakes, numerous reconnaissance teams conducted field investigations to document the structural damage and better understand the seismic performance of different building types. Observations from the affected region revealed that many reinforced concrete (RC) buildings, as well as reinforced and unreinforced masonry structures, experienced severe damage or total collapse. In contrast, only a limited number of steel structures were reported to be damaged, primarily because steel buildings are relatively uncommon in the earthquake-affected region. In this study, the seismic performance of an eight-story chevron braced steel frame designed according to the provisions of the Turkish Building Earthquake Code (TBEC-2018) is evaluated using recorded ground motions from the initial mainshock of the Kahramanmaraş earthquake sequence. Nonlinear time-history analyses are conducted to investigate the structural response under both pulse-like and non-pulse-like near-fault ground motions. The results indicate that pulse-like ground motions produce significantly larger interstory drift demands compared to non-pulse-like records, highlighting the increased vulnerability of chevron braced frame (CBF) systems when subjected to near-fault pulse-type earthquake excitations.