Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

www.isope.org

A Finite Element Based Study on Concrete Filled Steel Tube (CFST) Pile Used in Wharf Structure
Lan Lin, Facheng Wang*
Department of Civil Engineering, Tsinghua University
Beijing, People’s Republic of Chinaet al., 2013), the fire performance (Kodur, 2007; Han et al., 2003b; Huoet al., 2009), and the influence of concrete placement (Han and He,
2011b) and steel tube initial stress (Han and Yao, 2003a; Li et al., 2012)
on the performances above. Based on these studies, a series ofspecifications such as the Eurocode 4 (2007), AIJ guide (2008),
ANSI/AISC 360 (2016) and GB 50936 (2014) were proposed to provide
guidance for the design of concrete-filled steel tubular members.

ABSTRACTThis study investigated the application of concrete-filled steel tubes(CFSTs) in wharf piles. The deformation and mechanical characteristicsof CFST piles under lateral loading were investigated through the finite
element method. Furthermore, the mechanism of the steel tube effect wasrevealed. The findings of this study would provide a reference for theformulation of CFST pile design approaches and relevant specifications.

The wharf structure often uses the rock-socketed piles. The drilled shaft
and CFST piles have been commonly used as rock-socketed piles (Chenet al., 2011), with the CSFT pile being more suitable for construction
under offshore conditions for two reasons. One is that the structural
benefits of CFST are helpful for the pile to resist the wind, wave, current
load and other extreme loads, such as the ship impact load; the other isthat it is unnecessary to use shuttering during concrete construction,
reducing the offshore construction cost and time.

KEY WORDS: CFST; wharf; pile; finite element method.
INTRODUCTION
The concrete-filled steel tube (CFST) structure is one of the composite
members made by filling a steel tube with concrete. Due to structural
benefits, such as high bearing capacity, good plastic and toughness, andconvenient construction and economic efficiency (Han et al., 2014),
CFSTs have received increasing interest in recent decades. Fig. 1 shows
the three typical CFST cross sections, including the circular, square andrectangular cross sections.

Therefore, some scholars have begun to study the deformation andmechanical characteristics of CFST piles. For instance, Chen et al. (2011)
investigated the behavior of a large-diameter CFST rock-socketed pileunder lateral loads through the field tests and the finite element method(FEM). The results showed that the steel tube confinement could reduce
the pile displacement above the soil surface. Dong et al. (2020)
conducted a series of centrifugal model tests to study the lateral bearing
capacity of CFST piles. According to the test results, the lateral bearing
capacity of the pile increased significantly with the length of the steel
tube within the range of 0~12 cm.
In this study, to further research the deformation and mechanicalcharacteristics of CFST piles and reveal the mechanism of the steel tube
confinement effect from the perspective of structure, a finite element (FE)based investigation on CFST rock-socketed piles used in wharfs wasconducted. The behaviors of piles with steel tube and concrete only werecompared.

Fig. 1 Typical cross sections of concrete-filled steel tube
To promote the CFST application in civil engineering construction,
various studies have been conducted on CFST members during theirservice life to study the mechanical properties, including the static
performance in tension (Han et al., 2011a), bending (Han et al., 2004;2006), and torsion (Han et al., 2007), the dynamic performance undercycle load (Hajjar and Tort, 2010; Denavit & Hajjar, 2012; Nie et al.,2013) and impact load (Bambach et al., 2008; Deng et al., 2012; Wang

FINITE ELEMENT MODELLING AND VERIFICATIONAn FE model of CFST rock-socketed pile using the software ABAQUS
was developed in conjunction with Majishan port field tests (Chen et al.,1454