Seismic behavior of a rigid rocking structure under pulse-type excitation: Insights from the 2023 Pazarcık, Kahramanmaraş earthquake

Near-fault seismic events are characterized by high-amplitude velocity pulses that significantly influence the dynamic response of free-standing rigid structures. This study investigates the rocking behavior of a monolithic column under near-fault ground motion from the 2023 Pazarcık, Kahramanmaraş earthquake. Numerical simulations are conducted for the 2718 and 3138 seismic records, focusing on pulse extraction techniques that eliminate high-amplitude high-frequency components while also accounting for the fling-step effect. The results reveal a two-phase dynamic response: (1) a phase in which the structure requires a threshold acceleration amplitude to initiate rocking and (2) an overturning phase caused by the adverse effects of pulse motion. The extracted pulses alone fail to initiate rocking, whereas exposure to the full seismic record results in overturning due to the exceedance of the critical acceleration threshold. These findings highlight the necessity of considering complete ground motion characteristics rather than simplified pulse representations for accurate seismic assessment of rocking structures.