Effects of Near-Fault Ground Motions on Building Collapse: A Case Study from Hatay During the 2023 Kahramanmaraş Earthquake Sequence

Abstract

On 6 February 2023, two major earthquakes struck southeastern Türkiye, significantly affecting eleven provinces. These events caused more than 50,000 fatalities, and approximately 260,000 buildings either collapsed or were severely damaged. This study focuses on Hatay Province, one of the most severely affected regions. The influence of near-fault ground-motion characteristics, pulse-like velocity effects, local soil conditions, supershear rupture, and high vertical ground-motion accelerations on the observed structural damage was investigated. A detailed seismic performance assessment was conducted for a reinforced concrete building that collapsed during the Mw 7.7 Pazarcık earthquake. Nonlinear time-history analyses were performed using the recorded ground motions from nearby Station 3124, pulse-removed versions of the same record, and ground motions spectrum-matched to the TBEC-2018 (2018) DD-2 elastic design spectrum. The results showed that the original near-fault record produced severe lower-story damage concentrations and collapse-level damage patterns consistent with the observed collapse mechanism. Removal of the pulse component reduced the severity of the structural response, although significant inelastic behavior remained. In contrast, the spectrum-matched analyses resulted in substantially lower damage levels and did not reproduce the observed collapse behavior. The results indicate that near-fault and pulse-like ground-motion characteristics can significantly influence the seismic response and damage distribution of reinforced concrete buildings.