Estimating Site Amplifications for an Enhanced Understanding of Ground Motion Effects in Northwestern Türkiye: Fid-Bau Portal

Estimating Site Amplifications for an Enhanced Understanding of Ground Motion Effects in Northwestern Türkiye

Muratoğlu, Gamze / Askan, Ayşegül

Earthquake ground motions are influenced by various factors, including source characteristics, propagation path, and local site properties. Among these factors, local site conditions play a crucial role, leading to variations in ground shaking and consequential structural damage during large earthquakes. The presence of soil layers over solid bedrock can significantly amplify ground motions, highlighting the need to accurately quantify and comprehend site amplifications. This study focuses on investigating site amplifications in Northwestern Türkiye, employing a comprehensive approach. Initially, S-wave velocity models are identified at multiple sites throughout Turkey, followed by the categorization of stations based on NEHRP site classes. Subsequently, suitable input motions are selected for analysis, and 1D site response analyses are performed using the DEEPSOIL software. A compilation of shear wave velocity profiles with diverse resolutions and depths is utilized to capture the site-specific characteristics. Generic site amplification factors are derived for NEHRP site classes of A, B, C, and D in the Northwestern region of Türkiye. These factors are then compared with existing literature values, revealing notable disparities. The obtained amplification functions provide valuable insights into the amplification effects induced by local site conditions. By quantifying and understanding the site amplifications, this study contributes to a deeper comprehension of the factors influencing ground shaking during large earthquakes. The findings can be applied to improve seismic hazard assessments and inform the design of earthquake-resistant structures in Northwestern Türkiye. Furthermore, the developed amplification factors can be utilized in stochastic ground motion simulations, contributing to more accurate predictions and assessments of ground motions in the region.