Akarsu Köprü Temellerindeki Oyulma Riskinin Değerlendirilmesi

Yıl 2016, Cilt: 27 Sayı: 3, 7533 - 7549, 01.07.2016

A. Melih Yanmaz Melih Çalamak

Öz

Akarsu köprüleri, yapı-akım
etkileşimi nedeniyle altından akım geçmeyen köprülere oranla genellikle daha
fazla olumsuz koşullara maruz kalırlar. Bu nedenle, köprü yıkılma riskini
oluşturan bileşenlerden önemli bir tanesi de anılan etkileşimden kaynaklanan
risktir. Bu çalışmada orta ayaklar etrafındaki oyulma olayını etkileyen
değişkenlerde rastlanan belirsizlikler, tanımlanan olasılık yoğunluk
fonksiyonlarıyla irdelenmektedir. Analizlerde genel taban oyulması ve daralma
oyulması etkileri ihmal edilerek zamana bağlı bir temiz su oyulması yönteminin
içerdiği belirsizlikler kullanılmış ve Monte Carlo benzeşimleriyle risk
hesaplanmıştır. Oluşturulan modelde belirli akım, ayak geometrisi ve taban
malzemesi özelliklerinde köprünün maruz kalacağı oyulma riski saptanmaktadır.
Geliştirilen model örnek bir uygulama ile sunulmaktadır.

Anahtar Kelimeler

Köprü, oyulma, belirsizlik, risk, emniyet faktörü

Evaluation of Scour Risk at Foundations of River Bridges

Öz

River bridges are exposed to more inconvenient conditions due to the
structure-flow interaction compared to bridges having no contact with flow.
Therefore, one of the most important components of the bridge failure risk is
the risk induced by soil-flow interaction. In this study, the uncertainties of
the hydrological and hydraulic parameters affecting the scouring around bridge
piers are examined using appropriate probability density functions. In the
analyses, the uncertainties involved in the temporal variation of clear water
scouring mechanism are considered. Influences of general bed degradation of the
main channel and the contraction scour are ignored. The risk associated with
the scouring around piers is estimated using Monte Carlo simulations. In the
model, the scouring risk of the bridge pier is determined for the given flow,
pier geometry and bed material characteristics. The developed model is
presented with an application.

Anahtar Kelimeler

Bridge, scour, uncertainty, risk, safety factor

Kaynakça

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