STATIC ANALYSES OF THE EFFECT OF DEEP EXCAVATION ON THE BEHAVIOUR OF AN ADJACENT PILE IN SAND

Abstract

The influence of deep excavation on adjacent pile behaviour is an important issue to ensure its serviceability and stability. In this paper, the effect of deep excavation on an adjacent loaded single pile in saturated cohesionless soil was investigated by 3D finite element method. After verification of finite element model using centrifuge test results found in literature, a parametric study was conducted by varying the most influence factors on the pile behaviour such as excavation depth, distance from the pile to the excavation and pile head type. It was concluded that the excavation depth (He) with respect to pile length (Lp) has a significant effect on pile response. Among the three cases of He/Lp, the case of He/Lp=0.5 induced the maximum bending moment while the case of He/Lp= 1.5 induced the maximum pile lateral deflection. Moreover, the distance from the pile to the excavation site has also a significant influence on pile response and the induced bending moment in pile is inconsiderable after 9 m distance. Also, it is observed that the pile head type has an important effect on the pile behaviour especially in case of rigid head case.

Keywords

• deep excavation
• single pile
• finite element method
• sand

Kum Zemindeki Bir Derin Kazının Komşu Kazığın Davranışı Üzerindeki Etkisinin Statik Analizi

Abstract

Bitişik kazık davranışı üzerindeki derin kazı etkisinin incelenmesi, kazığın hizmet verebilirliğini ve stabilitesini değerlendirmek için önemli bir konudur. Bu çalışmada, bitişik yüklü tekil kazık üzerindeki derin kazının etkisi, doymuş kohezyonsuz zeminde, 3D sonlu elemanlar yöntemi kullanılarak araştırılmıştır. Literatürde bulunan santrifüj deney sonuçları kullanılarak sonlu elemanlar modelinin doğrulanmasından sonra; kazı derinliği, kazıkla kazı alanına olan mesafe ve kazık başı tipi gibi kazık davranışına en fazla etki eden faktörler üzerinde parametrik bir çalışma yapılmıştır. Kazık uzunluğuna göre kazı derinliğinin kazık davranışı üzerinde önemli bir etkiye sahip olduğu sonucuna varılmıştır. Üç farklı He/Lp durumu arasında, He/Lp= 0.5 durumu maksimum eğilme momentine neden olurken, He/Lp= 1.5 durumu maksimum kazık yanal sapmasına neden olmuştur. Ayrıca kazıktan kazıya olan mesafe de kazık tepkisi üzerinde önemli bir etkiye sahiptir ve kazıkta aktive olan eğilme momenti 9 m mesafeden sonra etkisini kaybetmiştir. Son olarak kazık başlığı tipinin kazık davranışı üzerinde önemli bir etkisi olduğu görülmüştür, özellikle rijit başlık durumunda bu etkiler daha dikkat çekicidir.

Keywords

• derin kazı
• tekil kazık
• kum zemin
• sonlu elemanlar yöntemi

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