Farklı Deprem Düzeylerinde Doğrusal Olmayan 1B Zemin Tepki Analizi ve TBDY (2018) ile Ampirik Büyütme Fonksiyonu Kıyaslaması

Abstract

Bu çalışmada, TBDY (2018) harita katsayıları kullanılarak DD1, DD2 ve DD3 deprem tehlike düzeylerine ait hedef spektrumlara spektral eşleştirme yöntemiyle uyarlanmış kayıtlar kullanılarak bir boyutlu (1B) zemin tepki analizleri gerçekleştirilmiştir. Analizlerde Hatay–İskenderun 3113 kuvvetli yer hareketi istasyonuna ait VS30 = 240 m/s hız profili kullanılmıştır. Kayıt seçimi, PEER NGA-West2 ve SMD-TR veri tabanlarından seçilmiştir. Her bir deprem düzeyi için doğrusal olmayan (NL) analizler uygulanmış; yüzey spektrumlarıyla taban spektrumlarının oranından periyot-bağımlı büyütme eğrileri elde edilmiştir. Elde edilen büyütme eğrilerinin ortalamaları, TBDY (2018)’de tanımlı Fs–F1 katsayıları ile ve İçen ve Sandıkkaya (2023) ampirik zemin büyütme modeliyle karşılaştırılmıştır. Sonuçlar, kısa periyot bölgesinde (T < 0.3 s) büyütmelerin yaklaşık 1 civarında olduğunu ve TBDY’nin Fs katsayılarının genel olarak konservatif bir yaklaşım sergilediğini göstermektedir. Uzun periyot bölgesinde (T > 0.6 s) ise büyütmelerin İçen ve Sandıkkaya (2023) modeliyle uyumlu olduğu, ancak TBDY’nin F1 katsayılarının bu bölgede daha düşük kaldığı ve dolayısıyla kısmen yetersiz tahminler ürettiği belirlenmiştir. Bu çalışma, farklı deprem şiddet düzeylerinde (DD1–DD3) doğrusal olmayan davranışın zemin büyütmesi üzerindeki etkisini nicel olarak ortaya koymakta ve TBDY (2018)’deki zemin büyütme katsayılarının özellikle uzun periyot bölgesinde yeniden kalibrasyon gerektirebileceğini göstermektedir.

Keywords

• Zemin Büyütmesi
• 1 B Zemin Tepki Analizi
• Doğrusal Olmayan Zemin Davranışı
• Yer Hareketi Tahmin Denklemi

Nonlinear 1D Site Response Analysis at Different Earthquake Levels and Comparison with TBEC (2018) and an Empirical Amplification Function

Abstract

In this study, one-dimensional (1D) nonlinear site response analyses were performed using ground motions matched to the DD1, DD2, and DD3 design spectra derived from the Turkish Building Earthquake Code (TBEC, 2018). The analyses employed the Hatay–İskenderun station (Station Code: 3113) profile with an uppermost 30 m average shear-wave velocity of VS30 = 240 m/s. Ground motions were selected from the PEER NGA-West2 and SMD-TR databases and spectrally matched to the corresponding hazard levels. For each level, period-dependent amplification functions were obtained as the ratio of surface to base spectral accelerations and compared with the Fs–F1 coefficients in TBEC (2018) and the empirical model of İçen and Sandıkkaya (2023). Results show that short-period (T < 0.3 s) amplifications are close to 1, indicating conservative Fs values, whereas long-period (T > 0.6 s) amplifications align well with the empirical model but are underestimated by TBEC (2018). The findings highlight the influence of nonlinear soil behavior under increasing shaking intensity and suggest that TBEC site coefficients may require recalibration, particularly in the long-period range.

Keywords

• Site Amplification
• 1 D Site Response Analysis
• Nonlinear Soil Behaviour
• Ground Motion Prediction Equation

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