Akademik Veri Yönetim Sistemi
Mediterranean Geosciences Union 4th Annual Meeting (MedGU-24), Barcelona, İspanya, 25 - 28 Kasım 2024, ss.1
Seismic waves have different physical behaviors in different site conditions after an earthquake. Particularly, significant changes in wave physics occur in the transition from rock to soft soil environment. The main reason is the different engineering properties of these two materials. The catastrophic destruction caused by the earthquake with a magnitude of Mw:7.7 in Pazarcık district of Kahramanmaraş on 06.02.2023 has once again underlined this fact. This earthquake once again showed that destruction and deaths occur in landslide areas and in fertile plain - weak alluvial deposits. Soil liquefaction was the main cause of the most of the earthquake destructions, but the loss of shear strength of weak soil conditions under dynamic loads was also another major factor. Official documents prepared after the earthquake show that destruction is not directly related to proximity or distance from the fault, and that destruction can occur even if the earthquake energy decreases hundreds of kilometers away. The ground motions resulted from the Pazarcık earthquake were analyzed with the use the AFAD (Disaster Affairs Department) strong ground motion network records, installed all over Turkey, and spectral analysis was applied on records obtained for important centers. In addition, design spectra were also analyzed within the scope of Turkish Building Earthquake Code (TBEC-2018) and the adequacy of the design spectrum was questioned by comparing the post-earthquake wave response with the design spectra. Furthermore, the numerical results are interpreted together with the satellite damaged structure analysis photographs taken and processed after the earthquake. As a result of the evaluations, it was clearly observed that the earthquake waves had high periods and amplitudes, especially in settlements built on deep alluvial basins. In addition, the response spectra of the time-acceleration records after the earthquake were well above the design spectra required by TBEC-2018. The damaged areas in the satellite images processed after the earthquake and the numerical results were compatible. The Pazarcık earthquake has once again shown that earthquakes cause destruction not in rocky areas but in weak alluvial-plain soil areas and that site selection is the most important factor in the long-term safety of engineering structures.
Keywords: Site selection, soil amplification, wave physics, response spectrum, Pazarcık earthquake, Kahramanmaraş, Turkey.