Boşluk Oranı ve Su Muhtevasının Kumların Düşük Kayma Modülüne Etkisi

Abstract

Deprem riski taşıyan bölgelerdeki kum numunelerinin dinamik davranışı ayrıntılı şekilde belirlenmeli ve yapı tasarım süreçlerinde dikkate alınmalıdır. Depremler, zeminlerin gerilme-şekil değiştirme ilişkisi ile dayanım özelliklerinde önemli değişikliklere yol açmakta, bu durum ise zemin deformasyonlarına ve yapısal hasarlara neden olmaktadır. Bu nedenle, bölgeye özgü zemin özelliklerini yansıtan maksimum kayma modülü, normalize kayma modülü azalma eğrisi ve sönüm oranı eğrisi gibi dinamik zemin parametrelerinin belirlenmesi gerekmektedir. Ancak, maksimum kayma modülünün laboratuvar ortamında belirlenmesi hem zaman alıcı hem de maliyetlidir. Bu nedenle, araştırmacıların kullanımına yönelik pratik çözümler sunan ampirik modeller geliştirilmiştir. Bu çalışmada, Türkiye’nin en aktif fay sistemlerinden biri olan Kuzey Anadolu Fay Zonu (KAFZ) üzerinde yer alan bir bölgeden alınan siltli kum numuneleri üzerinde farklı çevre basıncı, boşluk oranı ve su içeriği değerleri altında rezonant kolon deneyleri gerçekleştirilmiştir. Elde edilen deneysel veriler doğrultusunda, mühendislik uygulamalarında kullanılabilecek yüksek öngörü gücüne sahip bir ampirik model önerilmiştir.

Keywords

• Kayma Modülü
• Sönüm oranı
• Rezonant kolon
• Ampirik model

Effect of Void Ratio and Water Contents on the Small-Strain Shear Modulus for Sands

Abstract

The dynamic behavior of sand samples in earthquake-prone regions must be thoroughly characterized and incorporated into building design processes. Seismic events induce significant changes in the stress-strain behavior and strength characteristics of soils, which in turn lead to ground deformations and potential structural damage. Therefore, it is essential to determine key dynamic soil properties such as the maximum shear modulus, the normalized shear modulus reduction curve, and the damping ratio curve, which are representative of the site conditions. However, the laboratory-based determination of the maximum shear modulus is both time-consuming and costly. To address this limitation, empirical models have been developed to provide practical alternatives for researchers. In this study, a series of resonant column tests were conducted on silty sand samples collected from a site located along the North Anatolian Fault Zone (NAFZ), one of the most active fault systems in Turkey. The tests were performed under varying confining pressures, void ratios, and water contents. Based on the experimental results, an empirical model with high predictive capability is proposed for engineering applications.

Keywords

• Shear modulus
• Damping ratio
• Resonant column
• Empirical model.

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