Dynamic Properties of Soils in The Western Part of Ankara

Abstract

Nowadays, due to the easiness in gathering and analysing the data, natural sourced seismic methods are the preferred methods in microzonation studies. To determine the thickness and the variation of the shear wave velocity with depth and also the resonance frequency of the Quaternary sedimentary unit, forming the bed of the Ankara Stream, where settlement has been increasing rapidly in the west of the city of Ankara, Turkey, the data has been collected at 18 different points with the Extended Spatial Autocorrelation method and evaluated. Obtained results point out that the Quaternary unit, as the subject of the research, is thicker and has variable geometry. Findings indicate that the Vs30 value, included in international building codes and regulations and is widely used in geotechnical engineering, may not be sufficient for such regions. 

Keywords

• Shear Wave Velocity
• Correlation Function
• Spatial Autocorrelation Method
• Dispersion
• Damped Least Squares Method

Ankara Batı Kesimi Zeminlerin Dinamik Özellikleri

Öz

Günümüzde verilerin toplanması ve analiz edilmesindeki kolaylıkları nedeniyle doğal kaynaklı sismik yöntemler mikro bölgeleme çalışmalarında tercih edilmektedir. Ankara İlinin batısında yer alan, yerleşimin hızlı arttığı Ankara Çayı yatağını oluşturan Kuvaterner çökel birimin kalınlığını, kayma dalgası hızının derinlikle değişimini ve rezonans frekansını belirlemek amacıyla 18 farklı noktada Genişletilmiş Uzamsal Öz İlişki (SPAC) yöntemi ile veriler toplanmış ve değerlendirilmiştir. Elde edilen sonuçlar araştırmaya konu olan Kuvaterner yaşlı birimin beklenenden daha kalın olduğunu ve değişken geometri sunduğunu ortaya koymuştur. Bulgular uluslararası yapı kodlarında ve yönetmeliklerinde yer alan ve jeoteknik mühendisliğinde yaygın olarak kullanılan Vs30 değerinin bu tür bölgeler için yeterli olamayacağına işaret etmektedir.

Anahtar Kelimeler

• Makaslama Dalgası Hızı
• İlişki Fonksiyonu
• Uzamsal Öz İlişki Yöntemi
• Dispersiyon
• Sönümlü En Küçük Kareler Yöntemi

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