SERBEST VE RİJİT BAŞLI AÇIK DENİZ TEKİL KAZIK TEMELLERİNİN TEKRARLI YATAY YÜKLER ETKİSİ ALTINDAKİ DAVRANIŞI

Yıl 2017, Cilt: 22 Sayı: 1, 219 - 234, 08.05.2017

H. Ercan Taşan

https://doi.org/10.17482/uumfd.310966

Öz

Açık deniz tekil kazık temelleri rüzgar ve dalga kaynaklı
ağır tekrarlı yatay yüklere maruz kalmaktadır. Bu yükler nedeniyle kalıcı zemin
deplasmanları ve suya doygun zeminde aşırı boşluk suyu basıncı birikimi
gerçekleşebilmektedir. Çalışmada serbest ve rijit başlı tekil kazık
temellerinin tekrarlı yatay yükler altındaki davranışı sonlu elemanlar yöntemi
ile zeminde aşırı boşluk suyu basıncı gelişimi ve deplasman birikimi dikkate
alınarak incelenmiştir. Üç boyutlu sonlu elemanlar analizlerinde, zeminde aşırı
boşluk suyu basıncı gelişiminin belirlenmesi amacıyla iki fazlı modele dayanan
üç boyutlu elemanlar geliştirilmiştir. Böylelikle kazığın çevresindeki zeminde
boşluk suyu basıncı gelişiminin elde edilmesi mümkün olmuştur. Kumlu zemin,
tekrarlı yükler altındaki davranışının modellenmesine uygun olan bir
hipoplastik malzeme modeli ile tanımlanmıştır. Nümerik analizlerde özellikle
kazık, suya doygun zemin ve boşluk suyu basıncı etkileşimi üzerine
odaklanmıştır. Analiz sonuçları, tekrarlı yatay yük etkisindeki serbest ve
rijit başlı kazıkların deplasmanlarının tahmininde, suya doygun
zeminde aşırı boşluk suyu basıncı gelişimini dikkate almayan mevcut modellerin
yetersiz kaldığı göstermiştir.

Anahtar Kelimeler

Tekil kazık, açık deniz, tekrarlı yatay yükleme, sonlu elemanlar yöntemi, serbest başlı tekil kazık, rijit başlı tekil kazık, kumlu zemin, kalıcı deformasyon, aşırı boşluk suyu basıncı

Behaviour of Free and Fixed-Head Offshore Piles Under Cyclic Lateral Loads

Öz

Offshore
piles are subjected to cyclic lateral loads due to environmental loads, such as
wind and waves. These loads can lead to an accumulation of permanent soil
deformations and excess pore water pressures in saturated soils. Finite element
analyses are performed to investigate the behaviour of cyclic laterally loaded free-head
and fixed piles embedded in sandy saturated soil while considering such
accumulation effects. A three-dimensional fully coupled two-phase finite
element is developed and implemented on the basis of a two-phase model to
consider the pore water pressure development in saturated soil. In addition, a
hypoplastic constitutive model is used to describe the material behaviour of
sandy soil under cyclic loading. In the numerical analyses, special attention
is dedicated to interactions between the pile, the saturated soil and the pore
water. The results have shown that the pile displacements caused by cyclic
lateral loads are significantly underestimated for both pile head conditions by
approaches which do not take into account the impact of the pore water pressure
development in saturated sandy soil of the pile response.

Anahtar Kelimeler

Offshore piles, cyclic lateral loading, finite element method, fixed-head pile, free-head pile, sandy soil, accumulation, permanent displacement, pore water pressure, two-phase model

Kaynakça

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