Ageing and cyclic behaviour of axially loaded piles driven in chalk
File(s)Buckley_etal_2017_accepted_version.pdf (5.31 MB)
Accepted version
Author(s)
Buckley, RM
Jardine, R
Kontoe, S
Parker, D
Schroeder, FC
Type
Journal Article
Abstract
This paper reports a programme of static and cyclic loading tests on seven open steel tubes driven in low- to medium-density chalk at a well-characterised test site, describing their response to driving, ageing in situ and loading under both static and cyclic conditions. Back analysis of dynamic monitoring identifies the distributions of notably low shaft resistances that develop during installation, showing that these depend strongly on the relative pile tip depth (h/R). The shaft capacities available to ‘virgin’ piles are shown to increase markedly after driving, following a hyperbolic trend that led to a fivefold gain after 250 days. Pre-failed piles do not follow the same trend when re-tested. Pile exhumation confirmed that driving remoulded the chalk, creating a puttified zone around the shaft. Excess pore water pressure dissipation, which is likely to have been rapid during and after driving, led to markedly lower water contents close to the shaft. Axial cyclic testing conducted around 250 days after driving led to a range of responses, from manifesting stable behaviour over 1000 cycles to failing after low numbers of cycles after developing sharp losses of static capacity. The dependence of permanent displacement on the cyclic loading parameters is explored and characterised. The experiments provide the first systematic study of which the authors are aware into the effects of undisturbed ageing and cyclic loading on previously unfailed piles driven in chalk. Potential predictive tools may now be tested against the reported field measurements.
Date Issued
2018-02-01
Date Acceptance
2017-04-06
Citation
Geotechnique: international journal of soil mechanics, 2018, 68 (2), pp.146-161
ISSN
0016-8505
Publisher
ICE Publishing
Start Page
146
End Page
161
Journal / Book Title
Geotechnique: international journal of soil mechanics
Volume
68
Issue
2
Copyright Statement
Copyright © ICE Publishing, all rights reserved.
Sponsor
Technology Strategy Board
Engineering & Physical Science Research Council (EPSRC)
Institution of Civil Engineers
The Royal Society
Identifier
https://www.icevirtuallibrary.com/doi/10.1680/jgeot.17.P.012
Grant Number
101968
EP/C528484/1
1603
NA160438
Subjects
Science & Technology
Technology
Engineering, Geological
Engineering
chalk
offshore engineering
piles & piling
time dependence
DISPLACEMENT PILES
SHAFT FRICTION
SOIL STIFFNESS
SAND
PENETRATION
TESTS
CAPACITY
FIELD
MODEL
TIME
0905 Civil Engineering
0907 Environmental Engineering
0914 Resources Engineering and Extractive Metallurgy
Geological & Geomatics Engineering
Publication Status
Published
Date Publish Online
2017-07-07