SIST EN ISO 17892-8:2018

SLOVENSKI STANDARD
SIST EN ISO 17892-8:2018
01-junij-2018
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SIST-TS CEN ISO/TS 17892-8:2004
SIST-TS CEN ISO/TS 17892-8:2004/AC:2010
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Geotechnical investigation and testing - Laboratory testing of soil - Part 8:
Unconsolidated undrained triaxial test (ISO 17892-8:2018)
Geotechnische Erkundung und Untersuchung - Laborversuche an Bodenproben - Teil 8:
Unkonsolidierter undränierter Triaxialversuch (ISO 17892-8:2018)
Reconnaissance et essais géotechniques - Essais de laboratoire sur les sols - Partie 8:
Essai triaxial non consolidé non drainé (ISO 17892-8:2018)
Ta slovenski standard je istoveten z: EN ISO 17892-8:2018
ICS:
13.080.20 Fizikalne lastnosti tal Physical properties of soils
93.020 Zemeljska dela. Izkopavanja. Earthworks. Excavations.
Gradnja temeljev. Dela pod Foundation construction.
zemljo Underground works
SIST EN ISO 17892-8:2018 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 17892-8:2018

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SIST EN ISO 17892-8:2018


EN ISO 17892-8
EUROPEAN STANDARD

NORME EUROPÉENNE

March 2018
EUROPÄISCHE NORM
ICS 13.080.20; 93.020 Supersedes CEN ISO/TS 17892-8:2004
English Version

Geotechnical investigation and testing - Laboratory testing
of soil - Part 8: Unconsolidated undrained triaxial test (ISO
17892-8:2018)
Reconnaissance et essais géotechniques - Essais de Geotechnische Erkundung und Untersuchung -
laboratoire sur les sols - Partie 8: Essai triaxial non Laborversuche an Bodenproben - Teil 8:
consolidé non drainé (ISO 17892-8:2018) Unkonsolidierter undränierter Triaxialversuch (ISO
17892-8:2018)
This European Standard was approved by CEN on 18 January 2018.

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. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.

This European Standard exists 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 CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 17892-8:2018 E
worldwide for CEN national Members.

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SIST EN ISO 17892-8:2018
EN ISO 17892-8:2018 (E)
Contents Page
European foreword . 3

2

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SIST EN ISO 17892-8:2018
EN ISO 17892-8:2018 (E)
European foreword
This document (EN ISO 17892-8:2018) has been prepared by Technical Committee ISO/TC 182
"Geotechnics" in collaboration with Technical Committee CEN/TC 341 “Geotechnical Investigation and
Testing” the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by September 2018, and conflicting national standards
shall be withdrawn at the latest by September 2018.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes CEN ISO/TS 17892-8:2004.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 17892-8:2018 has been approved by CEN as EN ISO 17892-8:2018 without any
modification.

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SIST EN ISO 17892-8:2018

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SIST EN ISO 17892-8:2018
INTERNATIONAL ISO
STANDARD 17892-8
First edition
2018-02
Geotechnical investigation and
testing — Laboratory testing of soil —
Part 8:
Unconsolidated undrained triaxial test
Reconnaissance et essais géotechniques — Essais de laboratoire sur
les sols —
Partie 8: Essai triaxial non consolidé non drainé
Reference number
ISO 17892-8:2018(E)
©
ISO 2018

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SIST EN ISO 17892-8:2018
ISO 17892-8:2018(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2018
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
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CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved

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SIST EN ISO 17892-8:2018
ISO 17892-8:2018(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 2
5 Apparatus . 3
6 Test procedure . 6
6.1 General requirements and equipment preparation . 6
6.2 Preparation of specimens . 6
6.3 Application of cell pressure and initial readings . 7
6.4 Shearing . 8
6.5 Dismounting . 8
7 Test results . 9
7.1 Bulk density, dry density and water content . 9
7.2 Stage prior to shearing . 9
7.3 Shearing . 9
7.3.1 Corrected cross-sectional area . 9
7.3.2 Deviator stress . 9
7.3.3 Vertical strain .10
7.3.4 Undrained shear strength .10
7.4 Correction for elastic membrane .10
8 Test report .10
8.1 Mandatory reporting .10
8.2 Optional reporting .11
Annex A (normative) Calibration, maintenance and checks .12
Bibliography .14
© ISO 2018 – All rights reserved iii

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SIST EN ISO 17892-8:2018
ISO 17892-8:2018(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) Technical
Committee CEN/TC 341, Geotechnical investigation and testing, in collaboration with ISO Technical
Committee TC 182, Geotechnics, in accordance with the Agreement on technical cooperation between
ISO and CEN (Vienna Agreement).
This first edition of ISO 17892-8 cancels and replaces ISO/TS 17892-8:2004 and ISO/TS 17892-
8:2004/Cor.1:2006.
A list of all the parts in the ISO 17892 series can be found on the ISO website.
iv © ISO 2018 – All rights reserved

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SIST EN ISO 17892-8:2018
ISO 17892-8:2018(E)

Introduction
This document covers areas in the international field of geotechnical engineering never previously
standardized. It is intended that this document presents broad good practice throughout the world and
significant differences with national documents is not anticipated. It is based on international practice
(see Reference [1]).
© ISO 2018 – All rights reserved v

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SIST EN ISO 17892-8:2018

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SIST EN ISO 17892-8:2018
INTERNATIONAL STANDARD ISO 17892-8:2018(E)
Geotechnical investigation and testing — Laboratory
testing of soil —
Part 8:
Unconsolidated undrained triaxial test
1 Scope
This document specifies a method for unconsolidated undrained triaxial compression tests.
This document is applicable to the laboratory determination of undrained triaxial shear strength under
compression loading within the scope of geotechnical investigations.
The cylindrical specimen, which can comprise undisturbed, re-compacted, remoulded or reconstituted
soil, is subjected to an isotropic stress under undrained conditions and thereafter is sheared
under undrained conditions. The test allows the determination of shear strength and stress-strain
relationships in terms of total stresses.
Non-standard procedures such as tests with the measurement of pore pressure or tests with filter
drains are not covered in this document.
NOTE This document fulfils the requirements of unconsolidated undrained triaxial compression tests for
geotechnical investigation and testing in accordance with EN 1997-1 and EN 1997-2.
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 14688-1, Geotechnical investigation and testing — Identification and classification of soil — Part 1:
Identification and description
ISO 17892-1, Geotechnical investigation and testing — Laboratory testing of soil — Part 1: Determination
of water content
ISO 17892-2, Geotechnical investigation and testing — Laboratory testing of soil — Part 2: Determination
of bulk density
ISO 17892-3, Geotechnical investigation and testing — Laboratory testing of soil — Part 3: Determination
of particle density
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
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SIST EN ISO 17892-8:2018
ISO 17892-8:2018(E)

3.1
cell pressure
pressure applied to the cell fluid
3.2
deviator stress
difference between the applied vertical total stress and the horizontal total stress at the mid height of
the specimen
3.3
undrained shear strength
equal to one half of the deviator stress at failure in the unconsolidated undrained triaxial
compression test
3.4
failure
stress or strain condition at which one of the following criteria are met:
— peak deviator stress;
— a specified deformation criterion if a peak deviator stress has not been achieved, e.g., 15 %
vertical strain.
4 Symbols
A initial cross-sectional area of the specimen
i
A cross-sectional area of the specimen during shear
cor
a cross-sectional area of the piston if an external load cell is used
c undrained shear strength
u
D initial internal diameter of membrane (before it is placed on the specimen)
m
E elastic modulus for the membrane, measured in tension
m
f factor relating the vertical strain to the specimen volumetric strain
H initial height of the specimen prior to shearing (=H -ΔH )
s i i
H Initial height of specimen after preparation
i
h distance from the top of the top cap to the mid height of the specimen
P vertical load reading
t initial thickness of the unstressed membrane
m
V initial volume of the specimen after preparation
i
W gravity force acting on the sum of the deadweight hanger (if used), the piston, the top cap and
one half of the soil specimen
γ unit weight of the cell fluid
ΔH height change prior to shearing
i
ΔH height change during shearing
s
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SIST EN ISO 17892-8:2018
ISO 17892-8:2018(E)

(Δσ ) correction to vertical total stress due to the membrane
v m
ε vertical strain
v
(ε ) vertical strain of the membrane
v m
σ cell pressure at the mid height of the specimen
c
σ horizontal total stress at the mid height of the specimen
h
σ vertical total stress at the mid height of the specimen
v
ΔV specimen volume change (with reduction in volume being a positive numerical value)
5 Apparatus
5.1 General
The apparatus shall undergo regular maintenance, checks and calibration as specified in Annex A.
A schematic diagram of a typical apparatus for triaxial compression testing is shown in Figure 1.
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SIST EN ISO 17892-8:2018
ISO 17892-8:2018(E)

Key
1 alternative positions for load measuring device
2 air bleed
3 vertical displacement measuring device
4 piston
5 top cap
6 soil specimen
7 rubber membrane
8 O-rings
9 device for control and measurement of cell pressure
10 triaxial cell
P vertical load
Figure 1 — Schematic diagram of a typical unconsolidated undrained triaxial apparatus
5.2 Triaxial cell
5.2.1 The triaxial cell shall be able to withstand the applied cell pressure without leakage of cell fluid
out of the cell. Transparent cells should be used where possible.
5.2.2 The sealing bushing and piston guide shall be designed such that the piston runs smoothly with
minimal friction and maintains alignment.
5.2.3 The material of the top cap and the pedestal and the connection between the top cap and the
piston shall be such that their deformations are negligible compared to the deformations of the soil
specimen.
5.2.4 The diameter of the top cap and of the pedestal should normally be equal to the diameter of the
specimen. Specimens with diameters smaller than the diameter of the end caps may be tested provided
cavities under the membrane at the ends of the specimen can be avoided.
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SIST EN ISO 17892-8:2018
ISO 17892-8:2018(E)

5.2.5 The vertical stress applied to the specimen due to the weight of the top cap should not exceed
2 % of the estimated undrained shear strength of the specimen or 1 kPa, whichever is the greater.
5.3 Confining membrane
5.3.1 The soil specimen shall be confined by an elastic membrane which effectively prevents the cell
fluid from penetr
...