Group Effects of TLP Tendon Driven Piles in Normally Consolidated (NC) Clay

2014 ◽  
Author(s):  
Jianchun Cao
Keyword(s):  
Finite Element ◽  
Pile Group ◽  
Group Effect ◽  
Driven Piles ◽  
Pile Spacing ◽  
Axial Capacity ◽  
Lateral Capacity ◽  
Fea Model ◽  
Pile Group Effect ◽  
Group Effects

Long large-diameter driven piles (i.e., 2.0∼3.0m-diameter piles with a 100m penetration or deeper) have been usually used as Tension Leg Platforms’ (TLP) foundations in normally consolidated clay. In order to optimize a design, TLP designers would like to reduce the pile spacing, resulting in a pile group effect issue for pile geotechnical designers. This paper presents the development of a three-Dimensional Finite Element Analysis (3D FEA) model using Finite Element Code PLAXIS 3D to investigate the pile group effect of the TLP driven piles in normally consolidated clay. Using this model, a series of FEA runs were carried out. Firstly, the FEA model was used to examine the mobilization of axial capacity and the related group effect of a pile group, with various numbers of piles per group and different pile spacing. Secondly, the FEA model was used to investigate the group effects on the lateral capacity of a pile group, with respects of mobilization of lateral capacity, influence of loading direction, influence of pile spacing, and influence of number of piles in one group. These FEA results were also compared with the literature studies. Finally, recommendations on pile group effects for both axial capacity and lateral capacity were provided for TLP driven pile geotechnical designs in normally consolidated clay.

Numerical analysis of the deep soil failure mechanism for perimeter pile groups

2022 ◽  
Vol 12 (1) ◽  
pp. 1-26
Author(s):  
M. Watford ◽  
J. Templeman ◽  
Z. Orazalin ◽  
H. Zhou ◽  
A. Franza ◽  
...  
Keyword(s):  
Finite Element ◽  
Failure Mechanism ◽  
Pile Groups ◽  
Deep Soil ◽  
Pile Spacing ◽  
Lateral Capacity ◽  
Soil Failure ◽  
Dimensional Finite Element ◽  
Group Configuration

In this paper, the lateral limiting pressure offered by the deep ‘flow-around’ soil failure mechanism for perimeter (ring) pile groups in undrained soil is explored using two−dimensional finite element modelling. A parametric study investigates the role of group configuration, pile−soil adhesion, group size, pile spacing and load direction on group capacity and corresponding soil failure mechanisms. The finite element output show that the plan group configuration (square or circular) has a negligible influence on lateral capacity for closely spaced perimeter pile groups. When compared to ‘full’ square pile groups with the same number of piles, the present results suggest that for practical pile spacing (≳ two pile diameters), perimeter groups do not necessarily increase capacity efficiency, particularly if the piles are smooth. Nevertheless, perimeter groups are shown to be characterized by both the invariance of their capacity to the direction of loading and their highly uniform load-sharing between piles, which are beneficial features to optimize design.

Analysis of Vertical Bearing Capacity of Single-Row Pile Group of an Offshore Platform

2012 ◽  
Vol 188 ◽  
pp. 54-59
Author(s):  
Rui Hua Zhuo ◽  
Run Liu ◽  
Xin Li Wu ◽  
Yang Yang Zhao
Keyword(s):  
Bearing Capacity ◽  
Pile Group ◽  
Normal Operation ◽  
Deep Penetration ◽  
Group Model ◽  
Group Effect ◽  
Design Code ◽  
Vertical Bearing ◽  
Pile Group Effect ◽  
Vertical Bearing Capacity

The vertical bearing capacity of a special pile group of platform in an offshore gas field has been studied. Large diameter d (2.134 m), deep penetration l (96 m), small spacing sa (3.507 m), and only one row piles are the usual characteristics of the pile group foundation in offshore engineering. According to the requirements of the related design code, the super pile group effect has to be considered. However, with the usual design code, when sa/d, the ratio of spacing to diameter, is less than 2.0, there is no way to consider the pile group effect. In this paper, considering the occlusion effect of soil plug of pipe pile, several methods have been introduced to study the super pile group effect of the vertical bearing capacity. These methods include linear elastic theory method, the method recommended by the Code of Pile Foundation in Port Engineering (JTJ254-98), and the method with virtue of the existing pile group model test results. Meanwhile, the plugged and unplugged conditions have been considered, respectively. Through the analysis, the factors of safety in extreme and normal operation states are obtained, and the results satisfy the design specifications.

Interaction effects on load-carrying behavior of piled rafts embedded in clay from centrifuge tests

2015 ◽  
Vol 52 (10) ◽  
pp. 1550-1561 ◽  
Author(s):  
Donggyu Park ◽  
Junhwan Lee
Keyword(s):  
Pile Group ◽  
Interaction Effects ◽  
Group Effect ◽  
Piled Raft ◽  
Centrifuge Tests ◽  
Interaction Factor ◽  
Load Carrying ◽  
Lower Load ◽  
Load Tests ◽  
Pile Group Effect

In the present study, various interaction effects and load-carrying behavior of piled rafts embedded in clay were investigated. For this purpose, a series of centrifuge load tests were conducted using different types of model foundations, including single pile, group piles, piled raft, and unpiled raft. Different clay conditions were considered to prepare for centrifuge specimens. It was found that the pile group effect in clays is significant within initial loading range, showing lower load-carrying capacity. As settlement increases, the pile group effect becomes less pronounced. For both soft and stiff conditions, the values of the raft-to-pile (R-P) interaction factor varied initially, which became converged to some values around unity with increasing settlement. Similar tendency was observed for the pile-to-raft (P-R) interaction factor. The load responses of different pile components within the piled raft were not significantly different for the soft condition. For the stiff condition, the corner and inner piles showed the highest and lowest load-carrying capacities, respectively, due to piled-raft interaction effects. Correlations to cone resistance were analyzed and presented for the base and shaft resistances of piles for piled rafts.

scholarly journals Investigation of piles behavior under lateral cyclic load

2019 ◽  
Vol 39 (3) ◽  
pp. 213-220
Author(s):  
Chunhui Liu ◽  
Liang Tang ◽  
Xianzhang Ling
Keyword(s):  
Cyclic Load ◽  
Pile Group ◽  
Nonlinear Finite Element ◽  
Lateral Loading ◽  
Finite Element Models ◽  
Soil System ◽  
Pile Spacing ◽  
Practical Engineering ◽  
Number Of Cycles ◽  
Pile Group Effect

In this paper, the capability of 3D nonlinear finite element models is validated by single pile and 5x3 pile group filed experiments that is subjected to cyclic lateral loading. Then, a series 3D finite elements models are built to analyze the effect of the number of cycles of lateral loading, pile spacing, and pile group arrangement. The results have shown that the number of cycles affected the pile-soil system stiffness seriously, and the pile group effect became insignificant as the increase of pile spacing, while this effect became more significant with the increase of the pile group arrangement. In practical engineering, the pile spacing and pile group arrangement should be considered and chosen carefully.

scholarly journals Numerical evaluation of pile group effect of a composite group

2018 ◽  
Vol 58 (4) ◽  
pp. 1059-1067
Author(s):  
Youhao Zhou ◽  
Kohji Tokimatsu
Keyword(s):  
Numerical Evaluation ◽  
Pile Group ◽  
Group Effect ◽  
Pile Group Effect

scholarly journals Pile group effect on end bearing capacity and settlement of pile foundation

2008 ◽  
Vol 3 (1) ◽  
pp. 73-83
Author(s):  
Koichiro DANNO ◽  
Koichi ISOBE ◽  
Makoto KIMURA
Keyword(s):  
Bearing Capacity ◽  
Pile Foundation ◽  
Pile Group ◽  
Group Effect ◽  
End Bearing Capacity ◽  
Pile Group Effect
Sign in / Sign up

Export Citation Format

Share Document