SIST EN ISO 22476-11:2017

Geotechnical investigation and testing - Field testing - Part 11: Flat dilatometer test (ISO 22476-11:2017)

ISO 22476-11:2017 establishes guidelines for the equipment requirements, execution of and reporting on flat dilatometer tests.
NOTE          This document fulfils the requirements for flat dilatometer tests as part of the geotechnical investigation and testing according to EN 1997‑1 and EN 1997‑2.
The basic flat dilatometer test consists of inserting vertically into the soil a blade-shaped steel probe with a thin expandable circular steel membrane mounted flush on one face and determining two pressures at selected depth intervals: the contact pressure exerted by the soil against the membrane when the membrane is flush with the blade and, subsequently, the pressure exerted when the central displacement of the membrane reaches 1,10 mm.
Results of flat dilatometer tests are used mostly to obtain information on soil stratigraphy, in situ state of stress, deformation properties and shear strength. It is also used to detect slip surfaces in clays. The flat dilatometer test is most applicable to clays, silts and sands, where particles are small compared to the size of the membrane.

Geotechnische Erkundung und Untersuchung - Felduntersuchungen - Teil 11: Flachdilatometerversuch (ISO 22476-11:2017)

Dieses Dokument legt die Geräteanforderungen sowie die Durchführung von Flachdilatometerversuchen und die Erstellung entsprechender Berichte fest.
ANMERKUNG   Dieses Dokument erfüllt die Anforderungen für Flachdilatometerversuche im Rahmen der geotechnischen Erkundung und Untersuchung nach EN 1997 1 und EN 1997 2.
Der grundlegende Flachdilatometerversuch besteht darin, eine klingenförmige Stahlsonde mit einer dünnen dehnbaren kreisförmigen Stahlmembran, die auf einer Außenseite glatt anliegend angebracht ist, vertikal in den Boden einzubringen; dabei werden in ausgewählten Tiefen zwei Druckwerte bestimmt: der Kontaktdruck des Bodens gegen die glatt an der Klinge anliegende Membran und anschließend der aufgebrachte Druck, wenn die Verformung im Mittelpunkt der Membran 1,10 mm erreicht.
Der Hauptverwendungszweck der Ergebnisse von Flachdilatometerversuchen besteht in der Ermittlung von Angaben zum Schichtenaufbau des Bodens, zum In-situ-Spannungszustand, zu Verformungseigenschaften und zur Scherfestigkeit. Sie werden auch zur Erkennung von Rutschflächen in Tonen verwendet. Der Flachdilatometerversuch ist am besten geeignet für Tone, Schluffe und Sande, wenn die Körnung im Vergleich zu den Maßen der Membran klein ist.

Reconnaissance et essais géotechniques - Essais en place - Partie 11: Essai au dilatomètre plat (ISO 22476-11:2017)

Ce document établit les directives pour les exigences applicables à l'équipement, la réalisation et le compte-rendu des essais au dilatomètre plat.
NOTE       Ce document satisfait aux exigences relatives aux essais au dilatomètre plat dans le cadre des reconnaissances et essais géotechniques conformément aux normes EN 1997-1 et EN 1997-2.
L'essai de référence au dilatomètre plat consiste à insérer verticalement dans le sol une sonde en acier en forme de lame dont l'une des faces est équipée d'une fine membrane circulaire en acier extensible montée de façon affleurante et à déterminer, à des intervalles de profondeur prédéfinis, deux pressions : la pression de contact exercée par le sol sur la membrane lorsque la membrane est affleurante par rapport à la lame et la pression exercée lorsque le déplacement au centre de la membrane atteint 1,10 mm.
Les résultats des essais au dilatomètre plat sont principalement utilisés pour obtenir des informations relatives à la stratigraphie du sol, à l'état de contrainte in situ, aux propriétés de déformation ainsi qu'à la résistance au cisaillement. L'essai au dilatomètre plat convient plus particulièrement pour les argiles, les limons et les sables, lorsque les particules sont petites par rapport à la taille de la membrane.

Geotehnično preiskovanje in preskušanje - Preskušanje na terenu - 11. del: Ploskovni dilatometrski preskus (ISO 22476-11:2017)

Ta dokument podaja smernice v zvezi z zahtevami glede opreme, izvajanja ploskovnega dilatometrskega preskusa ter poročanja v zvezi z njim.
OPOMBA: Ta dokument izpolnjuje zahteve za ploskovne dilatometrske preskuse v okviru geotehničnega preiskovanja in preskušanja v skladu s standardoma EN 1997-1 in EN 1997-2.
Osnovni ploskovni dilatometrski preskus je sestavljen iz vstavitve jeklene preskuševalne glave v obliki rezila s tanko razširljivo krožno jekleno membrano, ki je na eni strani poravnana z glavo, navpično v tla in določitve dveh tlakov pri izbranih intervalih globine: kontaktni tlak, s katerim tla pritiskajo na membrano,
ko je membrana poravnana z glavo, in tlak, ki nastane, ko je membrana odmaknjena od sredine za 1,10 mm.
Rezultati ploskovnega dilatometrskega preskusa večinoma uporabljajo za pridobivanje informacij o stratigrafiji tal, obremenitvi na mestu preskusa, deformacijskih lastnostih in strižni trdnosti. Uporablja se tudi za odkrivanje drsnih površin v glini. Ploskovni dilatometrski preskus je najbolj primeren za glino, mulj in pesek, kjer so delci majhni v primerjavi z velikostjo membrane.

General Information

• Status: Published
• Public Enquiry End Date: 14-Feb-2016
• Publication Date: 11-Sep-2017
• ICS: 93.020 - Earthworks. Excavations. Foundation construction. Underground works
• Technical Committee: KON.007 - Geotechnics
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 02-Aug-2017
• Due Date: 07-Oct-2017
• Completion Date: 12-Sep-2017
• Ref Project: EN ISO 22476-11:2017 - Geotechnical investigation and testing - Field testing - Part 11: Flat dilatometer test (ISO 22476-11:2017)

Relations

• Replaces: SIST-TS CEN ISO/TS 22476-11:2008 - Geotechnical investigation and testing - Field testing - Part 11: Flat dilatometer test (ISO 22476-11:2005)
• Effective Date: 01-Oct-2017

Overview

EN ISO 22476-11:2017 - Geotechnical investigation and testing - Part 11: Flat dilatometer test (DMT) - provides standardized guidelines for equipment, execution and reporting of the flat dilatometer test. This ISO-adopted CEN standard describes the DMT procedure used in in situ geotechnical investigation and fulfils requirements of EN 1997‑1 and EN 1997‑2 for site investigation.

The flat dilatometer test uses a blade-shaped steel probe with a thin circular steel membrane mounted flush on one face. Two key pressure readings are obtained at selected depth intervals: the contact pressure when the membrane is flush and the pressure when the membrane centre reaches 1.10 mm deflection (with an initial signal at 0.05 mm). DMT results inform soil stratigraphy, in situ stress state, deformation properties and shear strength, and can detect slip surfaces in clays. It is most applicable to clays, silts and fine sands.

Key Topics and Requirements

• Equipment: Requirements for the dilatometer blade, membrane, pneumatic-electric cable, control and calibration unit, insertion apparatus and pressure source.
• Switch mechanism & signals: Internal blade switch that signals membrane deflections at 0.05 mm (A-pressure) and 1.10 mm (B-pressure).
• Measured pressures: Definitions and use of A-pressure, B-pressure and C-pressure (pressure when membrane returns towards A-position).
• Membrane calibration: Procedures to calibrate A and B membrane responses (air calibration pressures ΔA and ΔB) and gauge zero checks.
• Test procedure: Guidance on maintenance, insertion, sounding increments (commonly 100–300 mm), basic test sequence, dissipation tests (DMTA and DMTA‑s), and safety.
• Reporting: Required test documentation, site and equipment details, raw and corrected pressure data, interpretation notes and presentation of results.
• Informative annexes: Example interpretation formulae and references to other parts of the ISO 22476 series.

Applications and Users

Who uses EN ISO 22476-11:2017:

• Geotechnical and geotechnical site investigation engineers
• Engineering geologists and consultants
• Construction contractors and piling/subsurface works teams
• Testing laboratories and QA/QC personnel
• Regulators and authors of ground investigation specifications

Practical applications:

• Characterising soil stratigraphy and layering
• Estimating in situ stress, stiffness and deformation properties
• Assessing shear strength and detection of potential slip surfaces in clayey ground
• Complementing CPT, SPT and laboratory testing in foundation and earthworks design

Related Standards

• EN 1997‑1 / EN 1997‑2 (geotechnical design & investigations) - DMT fulfils their field-testing requirements
• Other parts of ISO 22476 (field testing series) for complementary in situ tests

Keywords: EN ISO 22476-11:2017, flat dilatometer test, DMT, geotechnical investigation, in situ testing, A-pressure, B-pressure, C-pressure, membrane calibration, dilatometer blade, soil stratigraphy.

Standards Content (Sample)

SLOVENSKI STANDARD
01-oktober-2017
1DGRPHãþD
SIST-TS CEN ISO/TS 22476-11:2008
*HRWHKQLþQRSUHLVNRYDQMHLQSUHVNXãDQMH3UHVNXãDQMHQDWHUHQXGHO
3ORVNRYQLGLODWRPHWUVNLSUHVNXV,62
Geotechnical investigation and testing - Field testing - Part 11: Flat dilatometer test (ISO
22476-11:2017)
Geotechnische Erkundung und Untersuchung - Felduntersuchungen - Teil 11:
Flachdilatometerversuch (ISO 22476-11:2017)
Reconnaissance et essais géotechniques - Essais en place - Partie 11: Essai au
dilatomètre plat (ISO 22476-11:2017)
Ta slovenski standard je istoveten z: EN ISO 22476-11:2017
ICS:
93.020 Zemeljska dela. Izkopavanja. Earthworks. Excavations.
Gradnja temeljev. Dela pod Foundation construction.
zemljo Underground works
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 22476-11
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2017
EUROPÄISCHE NORM
ICS 93.020 Supersedes CEN ISO/TS 22476-11:2005
English Version
Geotechnical investigation and testing - Field testing - Part
11: Flat dilatometer test (ISO 22476-11:2017)
Reconnaissance et essais géotechniques - Essais en Geotechnische Erkundung und Untersuchung -
place - Partie 11: Essai au dilatomètre plat (ISO 22476- Felduntersuchungen - Teil 11:
11:2017) Flachdilatometerversuch (ISO 22476-11:2017)
This European Standard was approved by CEN on 20 March 2017.

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: Avenue Marnix 17, B-1000 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 22476-11:2017 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 22476-11:2017) 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 AFNOR.
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 November 2017 and conflicting national standards
shall be withdrawn at the latest by November 2017.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
This document supersedes CEN ISO/TS 22476-11:2005.
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 22476-11:2017 has been approved by CEN as EN ISO 22476-11:2017 without any
modification.
INTERNATIONAL ISO
STANDARD 22476-11
First edition
2017-04
Geotechnical investigation and
testing — Field testing —
Part 11:
Flat dilatometer test
Reconnaissance et essais géotechniques — Essais en place —
Partie 11: Essai au dilatomètre plat
Reference number
ISO 22476-11:2017(E)
©
ISO 2017
ISO 22476-11:2017(E)
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2017 – All rights reserved

ISO 22476-11:2017(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 1
3.1 Terms and definitions . 1
3.2 Symbols . 4
4 Equipment . 4
4.1 Dilatometer equipment . 4
4.2 Insertion apparatus . 6
5 Test procedure . 7
5.1 Maintenance and checks . 7
5.2 Membrane calibration procedure . 8
5.3 Flat dilatometer test . 8
5.3.1 Operations before testing . 8
5.3.2 Basic test procedure . 8
5.3.3 C-pressure readings . 9
5.3.4 Operations after testing . 9
5.4 DMT dissipation test (DMTA) . 9
5.5 DMT short dissipation test (DMTA-s) . 9
5.6 Safety requirements .10
6 Test results .10
7 Report .11
7.1 General .11
7.2 Reporting of test results .11
7.2.1 General information .11
7.2.2 Location of sounding .12
7.2.3 Test equipment .12
7.2.4 Test procedure .13
7.2.5 Test results .13
7.3 Presentation of results .13
Annex A (informative) Example interpretation formulae .15
Bibliography .17
ISO 22476-11:2017(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: w w w . i s o .org/ iso/ foreword .html.
ISO 22476-11 was prepared by the European Committee for Standardization (CEN) Technical Committee
CEN/TC 341, Geotechnical investigating and testing, in collaboration with ISO Technical Committee
TC 182, Geotechniques, in accordance with the agreement on technical cooperation between ISO and
CEN (Vienna Agreement).
This first edition of ISO 22476-11 cancels and replaces ISO/TS 22476-11:2005, which has been
technically revised.
A list of all parts in the ISO 22476 series can be found on the ISO website.
iv © ISO 2017 – All rights reserved

INTERNATIONAL STANDARD ISO 22476-11:2017(E)
Geotechnical investigation and testing — Field testing —
Part 11:
Flat dilatometer test
1 Scope
This document establishes guidelines for the equipment requirements, execution of and reporting on
flat dilatometer tests.
NOTE This document fulfils the requirements for flat dilatometer tests as part of the geotechnical
investigation and testing according to EN 1997-1 and EN 1997-2.
The basic flat dilatometer test consists of inserting vertically into the soil a blade-shaped steel probe
with a thin expandable circular steel membrane mounted flush on one face and determining two
pressures at selected depth intervals: the contact pressure exerted by the soil against the membrane
when the membrane is flush with the blade and, subsequently, the pressure exerted when the central
displacement of the membrane reaches 1,10 mm.
Results of flat dilatometer tests are used mostly to obtain information on soil stratigraphy, in situ state
of stress, deformation properties and shear strength. It is also used to detect slip surfaces in clays. The
flat dilatometer test is most applicable to clays, silts and sands, where particles are small compared to
the size of the membrane.
2 Normative references
There are no normative references in this document.
3 Terms, definitions and symbols
3.1 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
3.1.1
dilatometer blade
dilatometer probe
blade-shaped steel probe that is inserted into the soil to perform a flat dilatometer test
3.1.2
membrane
thin circular steel diaphragm that is mounted flush on one face of the blade and is expanded by applying
a gas pressure at its back
ISO 22476-11:2017(E)
3.1.3
switch mechanism
apparatus housed inside the blade, behind the membrane, capable of switching on and off an electric
contact when the membrane expands and reaches two preset deflections equal, respectively, to
0,05 mm (A-pressure (3.1.10) reading) and 1,10 mm (B-pressure (3.1.11) reading)
3.1.4
signal
activation (signal on) or disconnection (signal off) by the switch mechanism between the blade and the
membrane to detect two preset positions of the membrane equal to 0,05 mm and 1,10 mm
3.1.5
pneumatic-electric cable
cable that connects the control unit to the blade, delivers gas pressure at the back of the membrane and
provides electric continuity between the control unit and the switch mechanism
3.1.6
control and calibration unit
set of suitable devices capable of supplying gas pressure to the back of the membrane and measuring
the pressure when the switch mechanism activates and disconnects the electric contact behind the
membrane
3.1.7
earth wire
wire connecting the control unit to the earth
3.1.8
pressure source
pressurized gas tank filled with any dry non-flammable and non-corrosive gas incorporating a pressure
regulator
3.1.9
dilatometer sounding
sequence of dilatometer tests executed from the same station at ground level in a vertical direction at
closely spaced intervals with depth increments ranging from 100 mm to 300 mm
3.1.10
A-pressure
A
pressure that is applied to the back of the membrane to expand its centre 0,05 mm against the soil
3.1.11
B-pressure
B
pressure that is applied to the back of the membrane to expand its centre 1,10 mm against the soil
3.1.12
C-pressure
C
pressure that is applied to the back of the membrane when the centre of the membrane returns to the
A-pressure position during a controlled, gradual deflection following the B-pressure
3.1.13
A-membrane-calibration-pressure
ΔA
suction recorded as a positive value that is applied to the back of the membrane to retract its centre to
the 0,05 mm deflection in air
2 © ISO 2017 – All rights reserved

ISO 22476-11:2017(E)
3.1.14
B-membrane-calibration-pressure
ΔB
pressure that is applied to the back of the membrane to expand its centre to the 1,10 mm deflection in air
3.1.15
zero gauge value
Z
M
pressure gauge deviation from zero when venting the blade to atmospheric pressure
3.1.16
soil pressure
p
corrected A-pressure (3.1.10)
Note 1 to entry: The term “contact pressure” is also used.
3.1.17
soil pressure
p
corrected B-pressure (3.1.11)
3.1.18
soil pressure
p
corrected C-pressure (3.1.12)
3.1.19
in situ pore water pressure
u
water pressure prior to blade insertion at the depth of the centre of the membrane
3.1.20
in situ effective vertical stress
σ’
vo
vertical stress prior to blade insertion at the depth of the centre of the membrane
3.1.21
dilatometer material index
I
D
index used to classify soils according to their response to the test
3.1.22
dilatometer
horizontal stress
index
K
D
index related to the in situ horizontal stress
3.1.23
dilatometer modulus
E
D
parameter related to the stiffness of the soil
3.1.24
pore pressure index
U
D
index related to the permeability of the soil
ISO 22476-11:2017(E)
3.1.25
contraflexure time
t
flex
time corresponding to the inflection point of a dissipation curve
3.2 Symbols
Symbol Name Unit
E dilatometer modulus kPa
D
I dilatometer material index —
D
K dilatometer horizontal stress index —
D
U pore pressure index
D
A A-pressure kPa
B B-pressure kPa
C C-pressure kPa
p corrected A-pressure kPa
p corrected B-pressure kPa
p corrected C-pressure kPa
t contraflexure time s
flex
u in situ pore pressure kPa
Z zero gauge value kPa
M
ΔA A-membrane-calibration-pressure kPa
ΔB B-membrane-calibration-pressure kPa
σ’ in situ effective vertical stress kPa
vo
4 Equipment
4.1 Dilatometer equipment
The equipment shall comprise the following items:
a) dilatometer blade with suitable threaded adaptor to connect to push rods;
b) membrane;
c) control and calibration unit;
d) pressure source;
e) pneumatic-electrical cable;
f) earth wire;
g) calibration syringe;
h) (optional) automated data acquisition system;
i) (optional) load cell.
The dimensions of the blade, the membrane and the apex angle of the penetrating edge shall be within
the limits shown in Figure 1.
4 © ISO 2017 – All rights reserved

ISO 22476-11:2017(E)
Dimensions in millimetres
Key
1 push rods 4 control and calibration cable unit 7 earth wire
2 blade 5 pressure tube 8 membrane
3 pneumatic electric cable 6 pressure source
Figure 1 — Dilatometer equipment and soil pressure definition
ISO 22476-11:2017(E)
The control and calibration unit shall have the following features:
— a socket for earthing;
— ability to control the rate of gas flow while monitoring and measuring the gas pressure transmitted
from the control unit to the membrane;
— ability to perform controlled venting of the pneumatic circuit;
— ability to signal the instants when the electric switch changes from on to off and vice versa;
— pressure measurement devices able to determine the pressure applied to the membrane with
intervals of 10 kPa and a reproducibility of 2,5 kPa at least for pressures lower than 500 kPa;
— pressure gauges having an accuracy of at least 0,50 %.
The pressure source shall be provided with a suitable regulator, valves and pressure tubing to connect to
the control unit. The pressure regulator should not exceed the maximum allowable pressure of the gage.
The pneumatic-electrical cable shall have metal connectors with wire insulators to prevent short circuit
and washers to prevent gas leakage.
The calibration syringe is used for calibration of membrane rigidity, at the beginning and at the end of
the test.
If the equipment incorporates a system for automatic data acquisition, such system will
— register the gas pressure and the status of the electroacustical signal,
— have transducers with linearity
...