FprEN ISO 22477-6

SLOVENSKI STANDARD
oSIST prEN ISO 22477-6:2025
01-maj-2025
Geotehnično preiskovanje in preskušanje - Preskušanje geotehničnih konstrukcij
- 6. del: Obremenilni preskus zemeljskih žebljev in skalnih vijakov (ISO/DIS 22477-
6:2025)
Geotechnical investigation and testing - Testing of geotechnical structures - Part 6: Load
testing of soil nails and rock bolts (ISO/DIS 22477-6:2025)
Geotechnische Erkundung und Untersuchung - Prüfung von geotechnischen Bauwerken
und Bauwerksteilen - Teil 6: Belastungsprüfung von Bodennägeln und Felsankern
(ISO/DIS 22477-6:2025)
Reconnaissance et essais géotechniques - Essais de structures géotechniques - Partie
6: Essai de chargement de clous et de boulons (ISO/DIS 22477-6:2025)
Ta slovenski standard je istoveten z: prEN ISO 22477-6
ICS:
93.020 Zemeljska dela. Izkopavanja. Earthworks. Excavations.
Gradnja temeljev. Dela pod Foundation construction.
zemljo Underground works
oSIST prEN ISO 22477-6:2025 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN ISO 22477-6:2025
oSIST prEN ISO 22477-6:2025
DRAFT
International
Standard
ISO/DIS 22477-6
ISO/TC 182
Geotechnical investigation and
Secretariat: BSI
testing — Testing of geotechnical
Voting begins on:
structures —
2025-03-14
Part 6:
Voting terminates on:
2025-06-06
Load testing of soil nails and rock
bolts
Reconnaissance et essais géotechniques – Essais de structures
géotechniques —
Partie 6: Essai de chargement de clous et de boulons
ICS: 93.020
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
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BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
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BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
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.
Reference number
ISO/DIS 22477-6:2025(en)
oSIST prEN ISO 22477-6:2025
DRAFT
ISO/DIS 22477-6:2025(en)
International
Standard
ISO/DIS 22477-6
ISO/TC 182
Geotechnical investigation and
Secretariat: BSI
testing — Testing of geotechnical
Voting begins on:
structures —
Part 6:
Voting terminates on:
Load testing of soil nails and
rock bolts
Reconnaissance et essais géotechniques – Essais de structures
géotechniques —
Partie 6: Essai de chargement de clous et de boulons
ICS: 93.020
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2025
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
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WHICH REFERENCE MAY BE MADE IN
or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
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TO SUBMIT, WITH THEIR COMMENTS,
CH-1214 Vernier, Geneva
NOTIFICATION OF ANY RELEVANT PATENT
Phone: +41 22 749 01 11
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PROVIDE SUPPORTING DOCUMENTATION.
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Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 22477-6:2025(en)
ii
oSIST prEN ISO 22477-6:2025
ISO/DIS 22477-6:2025(en)
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 .3
4 Equipment . 3
4.1 Test set-up .3
4.2 Reaction system .5
4.3 Loading device .5
4.4 Load measurement .5
4.5 Displacement measurement .5
4.6 Time and temperature measurement .6
5 Test elements . 6
5.1 General .6
5.2 Sacrificial elements .6
5.3 Production elements .6
6 Execution of the test . 6
6.1 Time period between installation of test element and testing.6
6.2 Test preparation .6
6.3 Proof load .6
6.4 Datum load .7
6.5 Check of the de-bonded length .7
7 Test report . 7
7.1 General .7
7.2 Data report .7
7.3 Interpretative report .8
8 Test Method A . 8
8.1 General .8
8.2 Investigation test .8
8.2.1 Loading procedure .8
8.2.2 Measurement and checks .9
8.2.3 Interpretation of data .9
8.3 Suitability test .11
8.3.1 Loading procedure .11
8.3.2 Measurement and checks . 13
8.3.3 Interpretation of data . 13
8.4 Acceptance test . 13
8.4.1 Loading procedure . 13
8.4.2 Measurement and checks .14
8.4.3 Interpretation of data .14
9 Test method B. 14
9.1 General .14
9.2 Loading procedure . 15
9.3 Measurement and checks .17
9.4 Interpretation of data .17
Annex A (normative) Creep rate and critical creep load P .18
c
iii
oSIST prEN ISO 22477-6:2025
ISO/DIS 22477-6:2025(en)
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 of 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 www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 182, Geotechnics, in collaboration with
the European Committee for Standardization (CEN) Technical Committee CEN/TC 341, Geotechnical
Investigation and Testing, 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.

iv
oSIST prEN ISO 22477-6:2025
DRAFT International Standard ISO/DIS 22477-6:2025(en)
Geotechnical investigation and testing — Testing of
geotechnical structures —
Part 6:
Load testing of soil nails and rock bolts
1 Scope
This document establishes the specifications for the execution of tension tests to be carried out on soil nails
and rock bolts.
NOTE 1 Soils nails and rock bolts are referred as elements in the scope of this document.
NOTE 2 This document covers but is not limited to grouted soil nails and rock bolts.
NOTE 3 This document does not provide specification for the number of tests, the type of test, the Test Method,
the value of the proof load and the limiting criteria. These aspects reside in EN 1997-3 or its national annex for CEN
countries and in similar national application documents for ISO countries.
This document provides specifications for three types of tension tests: investigation tests, suitability tests
and acceptance tests.
Two methods of testing are recognised by this document. Test Method A involves step-loaded maintained
load tension tests. Test Method B involves constant displacement rate tension tests.
This document provides specifications for the experimental devices, the measurement apparatus, the test
procedures, the definition and the presentation of the test results and the content of records, aiming at:
a) measuring the pull-out resistance of a soil nail or a rock bolt,
NOTE 4 A loading test performed using this standard provides the pulled-out resistance along the bonded
length, that might differ from the pull-out resistance considered in design.
b) checking that a soil nail or rock bolt behaves as designed.
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: Basis of structural design
EN 1997, Eurocode 7: Geotechnical design
3 Terms, definitions and symbols
For the purposes of this document, the terms and definitions given in EN 1990 and EN 1997 apply.

oSIST prEN ISO 22477-6:2025
ISO/DIS 22477-6:2025(en)
ISO and IEC maintain terminology 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/
3.1 Terms, definitions
3.1.1
applied load
P
tension load applied to the tendon head during the test
3.1.2
proof load
P
p
maximum load to which a test element is to be subjected
3.1.3
measured pull-out resistance
R
t,m
measured value of the pull-out resistance at the element-ground interface
3.1.4
tendon
soil nail or rock bolt reinforcing element (steel, fiber glass, etc.)
3.1.5
test element
element on which a test is performed
3.1.6
sacrificial element
test element installed in the same way as production elements, but not forming part of the completed
reinforced ground structure
3.1.7
production element
test element which forms part of the completed reinforced ground structure
3.1.8
investigation test
load test to establish the geotechnical ultimate load resistance of a soil nail or rock bolt at the interface
between the supporting element and the ground and to determine the behaviour of the element in the
working load range
3.1.9
suitability test
load test to confirm that a particular soil nail or rock bolt design will be adequate in particular ground
conditions
3.1.10
acceptance test
load test to confirm that an individual soil nail or rock bolt conforms with its acceptance criteria

oSIST prEN ISO 22477-6:2025
ISO/DIS 22477-6:2025(en)
3.2 Symbols
A Minimum cross section of the tendon, including the connecting parts
t
E elastic modulus of the tendon material
t
L bonded length of the test element
b
L debonded length of the test element
db
L external length of the tendon
e
P applied load
P datum load
a
P critical creep load
c
P’ intermediate parameter to derive the critical creep load P
c c
P proof load
p
R measured pull-out resistance
t,m
f (= f ) tensile strength
tk uk
f yield strength at 0,2 % strain
t0,2k
s axial displacement of tendon head
s axial displacement of tendon head at time t , for creep rate determination
1 1
s axial displacement of tendon head at time t , for creep rate determination
2 2
t time
t minimum load step duration for Test Method A
min
t time at the beginning of the interval used for creep rate determination
t time at the end of the interval used for creep rate determination
α creep rate (defined in Annex A)
α limiting criterion for creep rate for Test Method A
A
4 Equipment
4.1 Test set-up
The equipment comprises: one jack used as a loading device, displacement and load monitoring devices, a
reaction system, associated locking nuts, tendon extension, etc.
An example of test set-up is given in Figure 1.
The test set-up shall take into account the aim of the test, the ground conditions and the expected
displacement of the test element.
Where the facing system or the load test reaction system can influence the test result, then the test element
should be de-bonded over the zone of influence.

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