oSIST prEN ISO 22477-2:2022

Geotechnical investigation and testing - Testing of geotechnical structures - Part 2: Testing of piles: static tension load testing (ISO/DIS 22477-2:2022)

This document establishes the specifications for the execution of static pile load tests in which a single pile is subjected to an axial static load in tension in order to define its load-displacement behaviour.
This document is applicable to vertical piles as well as raking piles.
All types of piles are covered by this document. The tests considered in this document are limited to maintained load tests. Cyclic load tests are not covered by this document.
NOTE   This document is intended to be used in conjunction with EN 1997-1. EN 1997-1 provides 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.
This document provides specifications for the execution of static axial pile load tests:
a)   checking that a pile will behave as designed;
b)   measuring the resistance of a pile.

Geotechnische Erkundung und Untersuchung - Prüfung von geotechnischen Bauwerken und Bauwerksteilen - Teil 2: Statisch axiale Pfahlprobelastung auf Zug (ISO/DIS 22477-2:2022)

Reconnaissance et essais géotechniques - Essais des structures géotechniques - Partie 2: Titre manque (ISO/DIS 22477-2:2022)

Geotehnično preiskovanje in preskušanje - Preskušanje geotehničnih konstrukcij – 2. del: Preskušanje pilotov: statični natezni preskus (ISO/DIS 22477-2:2022)

General Information

• Status: Not Published
• Public Enquiry End Date: 29-Jun-2022
• ICS: 93.020 - Earthworks. Excavations. Foundation construction. Underground works
• Technical Committee: KON - Structures
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 20-Apr-2022
• Due Date: 07-Sep-2022
• Completion Date: 12-Jul-2022
• Ref Project: prEN ISO 22477-2 - Testing of geotechnical structures - Part 2: Pile load test - Static axially loaded tension test

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN ISO 22477-2:2022
01-junij-2022
Geotehnično preiskovanje in preskušanje - Preskušanje geotehničnih konstrukcij -
2. del: Preskušanje pilotov: preskus s statično natezno obtežbo (ISO/DIS 22477-
2:2022)
Geotechnical investigation and testing - Testing of geotechnical structures - Part 2:
Testing of piles: static tension load testing (ISO/DIS 22477-2:2022)
Geotechnische Erkundung und Untersuchung - Prüfung von geotechnischen Bauwerken
und Bauwerksteilen - Teil 2: Statisch axiale Pfahlprobelastung auf Zug (ISO/DIS 22477-
2:2022)
Reconnaissance et essais géotechniques - Essais des structures géotechniques - Partie
2: Titre manque (ISO/DIS 22477-2:2022)
Ta slovenski standard je istoveten z: prEN ISO 22477-2
ICS:
93.020 Zemeljska dela. Izkopavanja. Earthworks. Excavations.
Gradnja temeljev. Dela pod Foundation construction.
zemljo Underground works
oSIST prEN ISO 22477-2:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 22477-2:2022

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oSIST prEN ISO 22477-2:2022
DRAFT INTERNATIONAL STANDARD
ISO/DIS 22477-2
ISO/TC 182 Secretariat: BSI
Voting begins on: Voting terminates on:
2022-04-12 2022-07-05
Geotechnical investigation and testing — Testing of
geotechnical structures —
Part 2:
Testing of piles: Static tension load testing
ICS: 93.020
This document is circulated as received from the committee secretariat.
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
ISO/CEN PARALLEL PROCESSING
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
Reference number
NATIONAL REGULATIONS.
ISO/DIS 22477-2:2022(E)
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. © ISO 2022

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oSIST prEN ISO 22477-2:2022
ISO/DIS 22477-2:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
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oSIST prEN ISO 22477-2:2022
ISO/DIS 22477-2:2022(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 1
3.1 Terms, definitions . 2
3.2 Symbols . 2
4 Equipment . 3
4.1 General . 3
4.2 Reaction device . 3
4.3 Force Input . 4
4.3.1 General . 4
4.3.2 Specifications of force input . 5
4.4 Measurement of pile head displacements . 5
4.5 Measurement of pile load . 6
4.6 Pile instrumentation . 6
5 Test procedure .7
5.1 Test preparation . 7
5.1.1 Protections . 7
5.1.2 Construction of a test pile . 7
5.1.3 Test date . 7
5.2 Loading procedure . 8
5.2.1 General . 8
5.2.2 Load step sequence and duration of load steps for one cycle procedure . 8
5.2.3 Load step sequence and duration of load steps for multiple cycle procedure. 9
5.2.4 Maximum test load F . 10
p
5.2.5 Measuring intervals . 10
6 Test report .11
6.1 General . 11
6.2 General information. 11
6.3 Data report . 12
6.4 Interpretative report .13
Annex A (informative) Critical creep load in tension .19
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oSIST prEN ISO 22477-2:2022
ISO/DIS 22477-2:2022(E)
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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www.iso.org/iso/foreword.html.
This document was prepared by the European Committee for Standardization (CEN) in collaboration
with Technical Committee ISO/TC 182, Geotechnics in accordance with the Agreement on technical
cooperation between ISO and CEN (Vienna Agreement).
A list of all parts in the ISO 22477 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.
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oSIST prEN ISO 22477-2:2022
DRAFT INTERNATIONAL STANDARD ISO/DIS 22477-2:2022(E)
Geotechnical investigation and testing — Testing of
geotechnical structures —
Part 2:
Testing of piles: Static tension load testing
1 Scope
This document establishes the specifications for the execution of static pile load tests in which a single
pile is subjected to an axial static load in tension in order to define its load-displacement behaviour.
This document is applicable to vertical piles as well as raking piles.
All types of piles are covered by this document. The tests considered in this document are limited to
maintained load tests. Pile cyclic load tests are not covered by this document.
NOTE ISO 22477-2 is intended to 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.
This document provides specifications for the execution of static axial pile load test:
a) checking that a pile will behave as designed,
b) measuring the resistance of a pile.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
ISO 7500-1, Metallic materials — Calibration and verification of static uniaxial testing machines — Part 1:
Tension/compression testing machines — Calibration and verification of the force-measuring system
EN 1990, Eurocode 0: Basis of structural design
EN 1997-1, Eurocode 7: Geotechnical design — Part 1: General rules
EN 1997-2, Eurocode 7: Geotechnical design — Part 2: Ground investigation and testing
3 Terms, definitions and symbols
For the purposes of this document, the terms and definitions given in EN 1990, EN 1997-1, EN 1997-2
and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
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oSIST prEN ISO 22477-2:2022
ISO/DIS 22477-2:2022(E)
3.1 Terms, definitions
3.1.1
pile load
F
t
tension load applied to the head of the pile during the test
3.1.2
load increment
ΔF
increment of load added or removed during the test
3.1.3
pile diameter/Equivalent pile diameter
D
diameter of the pile
4A
Note 1 to entry: For non-circular pile with cross section A , the equivalent pile diameter equals .
π
3.1.4
working pile
pile for the foundation of a structure
3.1.5
test pile
pile to which loads are applied to determine the resistance-displacement characteristics of the pile and
the surrounding ground
3.1.6
measured tensile resistance
R
t,m
measured value of the tensile resistance at the ultimate limit state, in one or several pile load tests
Note 1 to entry: The recommended failure criterion may be defined in EN 1997-1 or its national annex.
3.1.7
creep rate
α
ratio of the increase in pile head displacement to the decimal logarithm of time during a specified time
interval
3.2 Symbols
A pile cross section
D pile diameter/equivalent pile diameter
F load applied to the head of the pile during the test
t
F critical creep load in tension
t,cr
F measured value of F in one or several pile load tests
t,cr,m t,cr
F characteristic axial tensile load
t,k
F predefined maximum load applied during the test
p
N axial force
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oSIST prEN ISO 22477-2:2022
ISO/DIS 22477-2:2022(E)
q unit shaft friction
s
q measured value of q
s,m s
q mobilised shaft friction
s,mob
R tensile resistance of the ground against a pile, at the ultimate limit state
t
R measured value of R in one or several pile load tests
t,m t
s axial displacement of pile at any depth z
s axial displacement of pile head
h
t time
z depth
α creep rate
4 Equipment
4.1 General
The selection of the equipment shall take into account the aim of the test, the ground conditions and the
expected displacement of the pile under the maximum test load.
4.2 Reaction device
The reaction device for pile tested in tension can be:
— shallow foundations;
— compression piles.
NOTE The reaction device can be 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 (see ISO 22477-1).
The influence of the reaction system on the test pile shall be minimized.
The minimum clear distances between the test pile and the reaction system elements depend on the
aim of the test (tensile resistance or stiffness).
For tests aiming at determining tensile resistance, minimum required distances are shown in Figures 1a
and 1b. The maximum value shall be applied.
NOTE Due to the presence of the reaction system, the tensile resistance can be overestimated. The provided
minimum distances limit the overestimation to approximately 5 %.
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oSIST prEN ISO 22477-2:2022
ISO/DIS 22477-2:2022(E)
Figure 1 — Minimum clear distances between test pile and reaction system
For assessment of the stiffness, the influence of reaction system is higher. If stiffness shall be assessed,
a minimum 10 D clear distance should be implemented. This clear distance value may be reduced if a
dedicated assessment is performed, taking into account the ground conditions. In any case, the clear
distance shall not be lower than the values given in Figures 1a and 1b.
NOTE This assessment can include a modification of the reaction system to reduce its influence on the
tested pile. For example, reduction of the skin friction of the reaction piles or the use of embedded jack(s) can be
considered.
For static pile load tests on micropiles, these distances may be reduced. However, the minimum clear
distance shall be 1,5 m.
The reaction system shall be designed to resist the maximum test load F in accordance with the
p
relevant European standards. The displacements of the reaction system shall be limited to ensure that
the load is applied axially for the duration of the test.
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. The displacement of
the working piles shall be monitored during the test.
Reaction systems should be arranged symmetrically around the test pile. In cases of non-symmetrical
reaction systems measures shall be taken to avoid detrimental rotation and/or translation of the
reaction system.
4.3 Force Input
4.3.1 General
One or more hydraulic jacks should be used to apply the load on the test pile.
If several hydraulic jacks are used to apply the test load, they shall be arranged symmetrically, of the
same model and be supplied by a common supply from one hydraulic unit. Each hydraulic jack shall be
provided with a shut-off valve and an additional pressure gauge.
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oSIST prEN ISO 22477-2:2022
ISO/DIS 22477-2:2022(E)
4.3.2 Specifications of force input
The achievable force of the jack(s) shall exceed F . The stroke of the jack(s) shall exceed the expected
p
deformations (pile head displacement and those of the reaction system under load).
It shall be possible to decrease or increase the load smoothly without any shocks or vibrations and to
maintain the load at any required value.
To satisfy the required accuracies, an automatic and continuous electric or hydraulic control and
regulation of the jack force may be used. Alternatively, a hand pump with accurate measurement of
pressure or load and permanent regulation may be considered.
The accuracy of the force regulator shall be better than 0,5 % of F or 10 kN, whichever is greater.
p
4.4 Measurement of pile head displacements
The displacements of the pile head shall be measured either by dial gauges or transducers, supported
from reference beams.
Reference beams should be supported independently from the test pile.
The clear distance between the supporting ends of the reference beams and the test pile and reaction
piles or the nearest edge of the shallow foundations should be at least 2,5 m or 2,5D, whichever is
greater.
One end of each reference beam should be free to slide.
The position of the reference beams shall be checked by a secondary control measuring system, such as
levelling methods or other measurement methods. The position of the pile head should be also checked
by this secondary control system.
The axial pile head displacement shall be measured at least with three transducers or gauges. They
shall be arranged symmetrically and parallel to the axis of the pile. The friction between the pile head
and the sensors should be minimized by using suitable devices such as
...