prEN ISO 22477-1

SLOVENSKI oSIST prEN ISO 22477-1:2006

PREDSTANDARD
marec 2006
Geotehnično preiskovanje in preskušanje – Preskušanje geotehničnih
konstrukcij – 1. del: Preskušanje nosilnih pilotov s statično osno stiskalno
obremenitvijo (ISO/DIS 22477-1:2005)
Geotechnical investigation and testing – Testing of geotechnical structures – Part
1: Pile load test by static axially loaded compression (ISO/DIS 22477-1:2005)
ICS 93.020 Referenčna številka
oSIST prEN ISO 22477-1:2006(en)
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

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EUROPEAN STANDARD
DRAFT
prEN ISO 22477-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2005
ICS 93.020

English Version
Geotechnical investigation and testing - Testing of geotechnical
structures - Part 1: Pile load test by static axially loaded
compression (ISO/DIS 22477-1:2005)
Reconnaissance et essais géotechniques - Essais de
structures géotechniques - Partie 1: Essai de charge
statique axiale en compression (ISO/DIS 22477-1:2005)
This draft European Standard is submitted to CEN members for parallel enquiry. It has been drawn up by the Technical Committee
CEN/TC 341.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations which
stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other language
made by translation under the responsibility of a CEN member into its own language and notified to the Management Centre has the same
status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN ISO 22477-1:2005: E
worldwide for CEN national Members.

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prEN ISO 22477-1:2005 (E)






Foreword


This document (prEN ISO 22477-1:2005) has been prepared by Technical Committee
CEN/TC 341 "Geotechnical Investigation and Testing", the secretariat of which is held by DIN,
in collaboration with Technical Committee ISO/TC 182 "Geotechnics".

This document is currently submitted to the parallel Enquiry.


2

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DRAFT INTERNATIONAL STANDARD ISO/DIS 22477-1
ISO/TC 182/SC 1 Secretariat: DIN
Voting begins on Voting terminates on

2005-12-22 2006-05-22
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION  •  МЕЖДУНАРОДНАЯ ОРГАНИЗАЦИЯ ПО СТАНДАРТИЗАЦИИ  •  ORGANISATION INTERNATIONALE DE NORMALISATION

Geotechnical investigation and testing — Testing of geotechnical
structures —
Part 1:
Pile load test by static axially loaded compression
Reconnaissance et essais géotechniques — Essais de structures géotechniques —
Partie 1: Essai de charge statique axiale en compression

ICS 93.020


ISO/CEN PARALLEL ENQUIRY
This draft International Standard is a draft standard developed within the European Committee for
Standardization (CEN) and processed under the CEN-lead mode of collaboration as defined in the
Vienna Agreement. The document has been transmitted by CEN to ISO for circulation for ISO
member body voting in parallel with CEN enquiry. Comments received from ISO member bodies,
including those from non-CEN members, will be considered by the appropriate CEN technical body.
Should this DIS be accepted, a final draft, established on the basis of comments received, will be
submitted to a parallel two-month FDIS vote in ISO and formal vote in CEN.

In accordance with the provisions of Council Resolution 15/1993 this document is circulated
in the English language only.
Conformément aux dispositions de la Résolution du Conseil 15/1993, ce document est
distribué en version anglaise seulement.

To expedite distribution, this document is circulated as received from the committee
secretariat. ISO Central Secretariat work of editing and text composition will be undertaken at
publication stage.
Pour accélérer la distribution, le présent document est distribué tel qu'il est parvenu du
secrétariat du comité. Le travail de rédaction et de composition de texte sera effectué au
Secrétariat central de l'ISO au stade de publication.


THIS DOCUMENT IS A DRAFT CIRCULATED FOR COMMENT AND APPROVAL. IT IS THEREFORE SUBJECT TO CHANGE AND MAY NOT BE REFERRED TO
AS AN INTERNATIONAL STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS BEING ACCEPTABLE FOR INDUSTRIAL, TECHNOLOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL TO BECOME STANDARDS TO WHICH
REFERENCE MAY BE MADE IN NATIONAL REGULATIONS.
©  International Organization for Standardization, 2005

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ISO/DIS 22477-1
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Copyright notice
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Violators may be prosecuted.

ii © ISO 2005 – All rights reserved

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ISO/DIS 22477-1
Contents Page
Foreword .v
1 Scope.1
2 Normative references.1
3 Terms, definitions and symbols .2
4 Equipment .3
4.1 General .3
4.2 Reaction device .4
4.3 Force input .4
4.4 Reference frame and points .5
4.5 Measurements .5
5 Test procedure.7
5.1 General .7
5.2 Test preparation .7
5.3 Loading procedure.8
6 Test results .10
7 Test report.11
Annex A (normative) Summarizing tables .20
Annex B (informative) Soil investigation .23
Annex C (informative) Number of test piles .24
Annex D (informative) Deductions from the test results.25

Figures
Figure 1 — Q-s plot .12
h
Figure 2 — t-Q plot .13
Figure 3 — t-s plot.14
h
Figure 4 — log(t) - s plot.15
h
Figure 5 — α - Q plot .16
Figure 6 — Q - s plot.16
h,inf
Figure 7 — Q, Q , Q - s plot .17
b s h
Figure 8 — Q, Q , Q - s plot .17
b s h
Figure 9 — Load distribution.18
Figure 10 — Unit friction mobilisation curves.19
Figure D.1 .26
Figure D.2 .26
Figure D.3 .26

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ISO/DIS 22477-1
Tables
Table A.1 — Equipment. 20
Table A.2 — Test procedure . 21

iv © ISO 2005 – All rights reserved

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ISO/DIS 22477-1
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
ISO 22477-1 was prepared by Technical Committee ISO/TC 182, Geotechnics, Subcommittee SC 1, and by
Technical Committee CEN/TC 341, Geotechnical investigation and testing in collaboration.
ISO 22477 consists of the following parts, under the general title Geotechnical investigation and testing —
Testing of geotechnical structures:
⎯ Part 1: Pile load test by static axially loaded compression
⎯ Part 2: Pile load test by static axially loaded tension (in preparation)
⎯ Part 3: Pile load test by static transversally loaded tension (in preparation)
⎯ Part 4: Pile load test by dynamic axially loaded compression test (in preparation)
⎯ Part 5: Testing of anchorages
⎯ Part 6: Testing of nailing (in preparation)
⎯ Part 7: Testing of reinforced fill (in preparation)

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DRAFT INTERNATIONAL STANDARD ISO/DIS 22477-1

Geotechnical investigation and testing — Testing of
geotechnical structures — Part 1: Pile load test by static axially
loaded compression
1 Scope
This Standard establishes the specifications for the execution of static pile load tests in which a single pile is
subjected to an axial static load in compression in order to define its load-displacement behaviour.
The provisions of EN 22477-1 apply to vertical piles as well as raking piles.
All types of piles are covered by this standard.
The tests considered in this Standard are limited to maintained load tests.
EN 22477-1 shall be used in conjunction with EN 1997-1. Numerical values of partial factors for limit states
and of correlation factors to derive characteristic values from static pile load tests to be taken into account in
design are provided in EN 1997-1. Guidance on analysis of the load testing results is given in the informative
Annex D.
This Standard provides specifications for:
a) Investigation tests, whereby the pile is loaded up to failure or close to failure ;
b) Control tests, whereby the pile is loaded up to a specified load in excess of the SLS design action.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 1990:2002, Eurocode 0 : Basis of structural design
EN 1997-1, Eurocode 7 : Geotechnical Design - Part 1 : General rules
EN 1536:1999, Execution of special geotechnical work - Bored piles
EN 10002-2, Metallic materials – Tensile testing – Part 2 : Verification of the force measuring system of the
tensile testing machines
EN 12699:2000, Execution of special geotechnical work - Displacement piles
prEN 14199:2001, Execution of special geotechnical work – Micropiles
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ISO/DIS 22477-1
3 Terms, definitions and symbols
For the purposes of this document, the terms and definitions given in EN 1990 and the following apply.
Terms, definitions and symbols specific for EN 22477-1-1 are given hereunder.
3.1
Q : pile load
the load applied to the head of the pile during the test
3.2
∆Q : load increment
an increment of load added or removed during the course of the test
3.3
Q
max
the predefined maximum load to be applied for the test
3.4
R

c;u
ultimate total pile (bearing) resistance in compression : the load per pile required to produce a condition of
failure in the ground or in the pile
NOTE Following 7.6.1.1 of EN 1997-1, the compressive resistance failure corresponds to the state in which the pile
foundation displaces significantly with negligible increase of resistance. In case that it is difficult to define an ultimate limit
state from a load settlement plot showing a continuous curvature, a settlement of the pile top equal to 10 % of the pile
base diameter should be adopted as the “failure” criterion.
3.5
R

b;u
ultimate pile base resistance
3.6
R

s;u
ultimate pile shaft resistance
3.7
q

s;u
ultimate unit shaft resistance
3.8
Q

b;u
ultimate unit base resistance
3.9
R

y
yield resistance:
a) a critical experimental load beyond which the rate of axial displacement takes place with a notably
increased increment
b) the load at which the rate of settlement increases without any significant increase in load
3.10
α : yield factor
y
the ratio of the increase in pile head displacement and the log of time during a specified time interval (usually
the last 30 min of a load step)
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ISO/DIS 22477-1
3.11
s , s : settlement
h b
the axial displacement of pile head or pile base respectively
3.12
D : equivalent pile base diameter
b
for noncircular pile sections with A being the area of the relevant pile base, the equivalent diameter equals
( 4 /π ). A
3.13
preliminary pile
a pile installed before the commencement of the main piling works or a specific part of the works for the
purpose of establishing the suitability of the chosen type of pile and for confirming its design, dimensions and
bearing resistance (EN 1536:1999)
3.14
trial pile
pile installed to assess the practicability and suitability of the construction method for a particular application
(EN 1536:1999)
3.15
working pile
pile for the foundation of a structure (EN 1536:1999)
3.16
test pile
pile to which loads are applied to determine the resistance deformation characteristics of the pile and the
surrounding ground (EN 1536:1999)
NOTE The test pile can be a preliminary pile, a trial pile or a working pile.
3.17
static pile load test
loading test where a pile is subjected to chosen axial and/or lateral forces at the pile had for the analysis of its
capacity
3.18
maintained pile load test
static loading test in which a test pile has loads applied in incremental stages, each of which is held constant
for a certain period or until pile motion has virtually ceased or has reached a prescribed limit (ML-test)
(EN 1536:1999)
4 Equipment
4.1 General
For guidance, the most relevant specifications related to the equipment, as detailed hereunder, are
summarised in Table A.1.
The selection of the equipment shall take into account the aim of the test, the ground conditions and the
execution of the test.
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ISO/DIS 22477-1
4.2 Reaction device
The reaction device for pile compressive loads can be :
⎯ dead load (kentledge);
⎯ ground anchorages either by tension piles or ground anchors;
⎯ a structure over the test pile (e. g. for jacked underpinning piles);
⎯ the test pile itself where the load is applied at depth by one or more hydraulic jacks which are cast into the
pile for bi-directional pile loading.
Dead load should not be used for tests of raking piles, unless particular measures are carefully considered
with respect to the stability and displacements of the kentledge system.
For all these reaction systems the clear distance between the test pile and the nearest edge of the kentledge
support or the anchorage shall be at least 2,5 m or 3 D , whichever is the greatest. These requirements might
b
be more severe for test piles that act predominantly through skin friction or when using ground anchors as a
reaction device.
The reaction system shall be designed for the maximum test load Q in accordance with the relevant
max
European standards.
To avoid uplift or instability of the kentledge, the dead load should be in excess of the maximum test load
Q by at least 10 %.
max
Working piles may be used as reaction piles, provided that their structural resistance is sufficient and there is
no detrimental effect on their ability to perform as part of the structure
Reaction piles and anchors should be arranged symmetrically around the test pile. In cases of non-
symmetrical reaction systems measures shall be taken to avoid excessive rotation and/or translation of the
reaction system.
4.3 Force input
Unless otherwise required by the design, one or more hydraulic jacks shall be used to apply the load on the
test pile.
NOTE 1 For top-down loading the hydraulic jack is seated on top of the pile between the reaction assembly and the
pile head.
NOTE 2 For bi-directional loading the hydraulic jack is cast into the pile to apply an axial load in two opposite directions.
The jacking force and stroke of the jack shall be matched to Q and to the expected deformations (pile head
max
displacement and those of the reaction system under load). A minimum stroke of 150 mm and 15 % D is
b
recommended.
It shall be possible to decrease or increase the load fluently without any shocks or vibrations and to maintain
the load at any required value. For investigation tests an automatic and continuous electric or hydraulic control
and regulation of the jack force should be used. For control tests a hand pump control and regulation may be
used.
To safeguard the test, it should be possible to repair the equipment without excessive loss of load on the pile.
The accuracy of the force regulation shall by in accordance to the test purpose. It should allow the load Q to
be applied and maintained during each load step within the following relative variation:
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ISO/DIS 22477-1
⎯ For investigation tests : ± 0,5 % of Q and ± 1,0 % of Q
max
⎯ For control tests : ± 3 % of Q
NOTE More severe requirements may be required for time dependent analysis of the test results.
4.4 Reference frame and points
The displacements of the pile head can be measured either by dial gauges or transducers, supported from
reference beams or alternatively, the displacements may be measured independently from reference beams
by advanced levelling methods such as electronic optical devices.
It is recommended to use reference beams supported independently from the test pile. Alternatively, beams
may be fixed on the pile head. In this case the displacements of the pile head or the beams should be
measured from independent reference marks.
The clear distance between the supporting ends of the reference beams (or alternatively the reference marks)
and the test pile and reaction piles or the nearest edge of the kentledge support shall be at least 2,5 m or
3 × D, whichever is the greatest.
One end of each reference beam should be free to slide.
4.5 Measurements
4.5.1 Measurement of pile head displacements
The pile head displacements shall be measured with at least three displacement transducers or dial gauges
supported from reference beams.
The overall accuracy of the measured pile head displacement shall be of MAX (0,1 mm; 0,2 % of the read out
value) or better. Therefore dial gauges or transducers shall enable readings to be made to an accuracy of at
least 0,01 mm.
The dial gauges or transducers should also have a sufficient measuring range, in order to avoid readjustment
during testing.
The pile head displacements may be measured by alternative techniques (e.g. optical levelling) which are
independent from the reference beam.
The optical levelling measurements shall be controlled by reference to one or more fixed reference points.
When relevant, complementary optical levelling of at least one point fixed to the test pile head shall be
provided, as a control of the transducers or dial gauges measurements.
The potential transversal displacement of the test pile under axial load should be checked by two dial gauges
or transducers with the same accuracy as above, positioned in orthogonal directions and fixed on reference
beams. Alternatively, horizontal pile head displacements can be obtained from horizontal survey.
The displacements of the reference beams should be checked by optical levelling at least at the end of each
load step.
To safeguard against sudden failure of the supports, the corner points of a kentledge, or the anchor heads
should be included in the levelling checks.
4.5.2 Measurement of pile load
Load measurement can be obtained from a load cell (load cells) or from the pressure of the jack or jack
system, by means of suitable calibrated pressure gauges.
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ISO/DIS 22477-1
The load measurement devices shall be calibrated in accordance with EN 10002–2 by a certified institute.
For investigation tests, the accuracy of the load measurement should be 1 % or less.
For control tests, the accuracy of the load measurement should be 3 % or less.
When a load cell is used, it shall have been calibrated within a period of 12 months before the test.
When the load is measured from the jack pressure, the calibration of the entire jack system
(jack + pump + pressure gauges) shall be executed within a period of 1 month before the test.
4.5.3 Pile instrumentation
The load distribution along the pile shaft may be determined by means of direct or indirect measurement of
the force at cross sections of the pile at various depths.
The following measurement devices may be used:
⎯ removable extensometer;
⎯ telltales;
⎯ strain gauges or strain gauge devices;
⎯ vibrating wire strain gauge;
⎯ load cell at the pile base or within the pile shaft;
⎯ hydraulic jacks at the base of the pile or built-in in the shaft of the pile.
The depth, the number of measuring levels, the number of devices at each level, should take into account the
ground conditions, the type and the size of the test pile and the aim of the test.
Removable extensometers should be installed in the centre of smaller diameter piles (shaft diameter < 0,5 m),
or in diametrically opposed pairs for larger diameter piles (shaft diameter > 0,5 m), and this for each depth to
be measured.
Strain gauges or strain gauge devices should be fixed to the reinforcement bars rods or embedded in the
concrete of concrete piles or attached to the walls of steel piles at least in diametrically opposed pairs for each
depth to be measured.
The cross section A and the deformation properties of the pile material (modulus of elasticity) shall be
determined.
For reinforced concrete piles, a composite composed deformation modulus shall be applied comprising the
concrete, the reinforcement and embedded parts. The effective deformation modulus of the pile shaft should
be determined directly by :
⎯ laboratory testing on a piece of pile made and conserved under the same conditions as the tested pile;
⎯ in situ measurement of the pile deformation on the free upper part of the pile at a level below the pile
head where uniform stress distribution can be presumed.
For steel piles, the manufacturer’s information or common methods may be used to determine the deformation
modulus.
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ISO/DIS 22477-1
5 Test procedure
5.1 General
For guidance, the most relevant specifications related to the test procedure, as detailed hereunder, are
summarised in Table A.2.
5.2 Test preparation
5.2.1 Protections
Throughout the test period all measuring equipment shall be protected from weather (direct sunlight, wind,
rain) and other disturbances.
NOTE It is es
...