Akarsu Köprü Temellerindeki Oyulma Riskinin Değerlendirilmesi

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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