SIST EN ISO 22476-4:2021

SLOVENSKI STANDARD
01-december-2021
Nadomešča:
SIST EN ISO 22476-4:2013
Geotehnično preiskovanje in preskušanje - Preskušanje na terenu - 4. del: Preskus
z Ménardovim presiometrom (ISO 22476-4:2021)
Geotechnical investigation and testing - Field testing - Part 4: Prebored pressuremeter
test by Ménard procedure (ISO 22476-4:2021)
Geotechnische Erkundung und Untersuchung - Felduntersuchungen - Teil 4:
Vorgebohrter Pressiometerversuch nach Ménard (ISO 22476-4:2021)
Reconnaissance et essais géotechniques - Essais en place - Partie 4: Essai
pressiomètrique dans un forage préalable selon la procédure Ménard (ISO 22476-
4:2021)
Ta slovenski standard je istoveten z: EN ISO 22476-4:2021
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 22476-4
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2021
EUROPÄISCHE NORM
ICS 93.020 Supersedes EN ISO 22476-4:2012
English Version
Geotechnical investigation and testing - Field testing - Part
4: Prebored pressuremeter test by Ménard procedure (ISO
22476-4:2021)
Reconnaissance et essais géotechniques - Essais en Geotechnische Erkundung und Untersuchung -
place - Partie 4: Essai pressiomètrique dans un forage Felduntersuchungen - Teil 4: Vorgebohrter
préalable selon la procédure Ménard (ISO 22476- Pressiometerversuch nach Ménard (ISO 22476-
4:2021) 4:2021)
This European Standard was approved by CEN on 15 August 2021.

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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, 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
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 22476-4:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 22476-4:2021) 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 March 2022, and conflicting national standards shall
be withdrawn at the latest by March 2022.
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 EN ISO 22476-4:2012.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN websites.
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, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 22476-4:2021 has been approved by CEN as EN ISO 22476-4:2021 without any
modification.
INTERNATIONAL ISO
STANDARD 22476-4
Second edition
2021-09
Geotechnical investigation and
testing — Field testing —
Part 4:
Prebored pressuremeter test by
Ménard procedure
Reconnaissance et essais géotechniques — Essais en place —
Partie 4: Essai pressiomètrique dans un forage préalable selon la
procédure Ménard
Reference number
ISO 22476-4:2021(E)
©
ISO 2021
ISO 22476-4:2021(E)
© ISO 2021
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: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

ISO 22476-4:2021(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 1
3.1 Terms and definitions . 1
3.2 Symbols . 3
4 Equipment . 6
4.1 General description . 6
4.2 Pressuremeter probe . 6
4.2.1 General. 6
4.2.2 Probe with flexible cover . 8
4.2.3 Probe with flexible cover and an additional more rigid protection . 8
4.2.4 Probe with flexible cover and slotted tube. 9
4.3 Connecting lines and injected fluid .10
4.4 Pressure and volume control unit .11
4.4.1 General.11
4.4.2 Measurement and control .11
4.4.3 Data logger .12
5 Test procedure .12
5.1 Assembling the parts .12
5.2 Calibration and corrections .13
5.3 Pressuremeter test pocket and probe placing .13
5.4 Preparation for testing .13
5.5 Establishing the loading programme .14
5.6 Establishing the pressure of the guard cells for tri-cell probes .15
5.7 Expansion .15
5.7.1 General.15
5.7.2 Readings and recordings .15
5.7.3 End of test .16
5.8 Back-filling of the pockets .16
5.9 Safety requirements .16
6 Test results .16
6.1 Data sheet and field print-out or display .16
6.1.1 Data sheet for type A control unit .16
6.1.2 Site print-out for type B and C control units .17
6.1.3 Raw pressuremeter curve .17
6.2 Corrected pressuremeter curve .17
6.3 Calculated results.18
7 Reporting .19
7.1 General .19
7.2 Field report .19
7.3 Test report .19
7.3.1 General.19
7.3.2 Ménard pressuremeter test report .19
7.3.3 Pressuremeter tests log .20
Annex A (normative) Geometrical features of pressuremeter probes .22
Annex B (normative) Calibration and corrections .24
Annex C (normative) Placing the pressuremeter probe in the ground .33
Annex D (normative) Obtaining pressuremeter parameters .41
ISO 22476-4:2021(E)
Annex E (normative) Uncertainties .51
Annex F (informative) Pressuremeter test records .53
Bibliography .60
iv © ISO 2021 – All rights reserved

ISO 22476-4:2021(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 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).
This second edition cancels and replaces the first edition (ISO 22476-4:2012), which has been
technically revised.
The main changes compared to the previous edition are as follows:
— types of probes;
— correction procedures;
— probe placing techniques in Annex C;
— clarification of D;
— harmonization of terms and symbols.
A list of all parts in the ISO 22476 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.
ISO 22476-4:2021(E)
Introduction
The Ménard pressuremeter test is performed by the radial expansion of a cylindrical probe of a
minimum slenderness of 6, placed in the ground (see Figure 1). During the injection of the fluid volume
in the probe, the inflation of the measuring cell first brings the outer cover of the probe into contact
with the pocket wall and then producing ground displacement. Pressure applied to and the associated
radial expansion of the probe are measured either by volume or radial transducers and recorded so as
to obtain the stress-strain relationship of ground as tested.
Key
1 ground surface p applied pressure
2 ground A-A axial section
3 pressuremeter test pocket B-B cross section
4 expanding pressuremeter probe
Figure 1 — Principle of a Ménard pressuremeter test
Together with results of investigations with ISO 22475-1 being available or at least with identification and
description of the ground according to ISO 14688-1 and ISO 14689 obtained during the pressuremeter
vi © ISO 2021 – All rights reserved

ISO 22476-4:2021(E)
test operations, the tests are performed in order to obtain the quantitative determination of a ground
profile, including
— the Ménard pressuremeter modulus E ,
M
— the Ménard pressuremeter limit pressure p , and
lM
— the Ménard creep pressure p .
f
NOTE 1 This document fulfils the requirement for the Ménard pressuremeter test, as part of geotechnical
investigation and testing according to EN 1997-1 and EN 1997-2.
NOTE 2 This document refers to a probe historically described as the “60 mm (also called BX) G type probe”,
that corresponds to a 58 mm diameter probe with a drilling diameter between 60 mm and 66 mm with a pressure
limitation of 5 MPa. If specified by the relevant authority or agreed for a specific project by the relevant parties, a
different pressure, not higher than 8 MPa, can be set.
NOTE 3 G type probe refers to probes with an external cover creating guard cells (see 4.2).
NOTE 4 Ménard pressuremeter tests can be carried out with other diameter probes such as 32 mm, 44 mm and
76 mm probes.
NOTE 5 Examples of other probe and pocket drilling dimensions are indicated in Table 1.
Table 1 — Probe and pocket drilling dimensions
Probe Probe Drilling diameter
(mm)
Designation Diameter Min Max
mm
AX 44 46 52
NX 70/74 74 80
NOTE 6 Tests with maximum pressures higher than 8 MPa are dealt by ISO 22476-5.
NOTE 7 For the scope of this document (and the associated measuring device and maximum uncertainties
given in Table E.1), E values up to 500 MPa (that can be determined by calculation) can be commonly obtained.
M
Enhancement of equipment to reduce uncertainties can be implemented to increase the range of measurements.
For example, use of GA type equipment and of a shunt for volume measurement can allow measuring E values
M
up to 10 000 MPa. Uncertainty calculation can be used to confirm the relevance of these pressuremeter moduli.
INTERNATIONAL STANDARD ISO 22476-4:2021(E)
Geotechnical investigation and testing — Field testing —
Part 4:
Prebored pressuremeter test by Ménard procedure
1 Scope
This document specifies equipment requirements, the execution of and reporting on the Ménard
pressuremeter test.
This document describes the procedure for conducting a Ménard pressuremeter test in natural grounds,
treated or untreated fills, either on land or off-shore.
The pressuremeter tests results of this document are suited to a quantitative determination of ground
strength and deformation parameters. They can yield lithological information in conjunction with
measuring while drilling performed when creating the borehole (according to ISO 22476-15). They can
also be combined with direct investigation (e.g. sampling according to ISO 22475-1) or compared with
other in situ tests (see 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 14689, Geotechnical investigation and testing — Identification, description and classification of rock
ISO 22475-1, Geotechnical investigation and testing – Sampling by drilling and excavation and ground
water measurements – Part 1: Technical principles for execution
ISO 22476-15, Geotechnical investigation and testing — Field testing — Part 15: Measuring while drilling
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:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1.1
pressuremeter probe
cylindrical flexible probe which can be expanded by the application of hydraulic pressure and/or
pressurised gas
ISO 22476-4:2021(E)
3.1.2
pressuremeter control unit
set of suitable devices capable of supplying fluid and/or gas pressure to the probe, to adjust pressure
steps and take readings of the probe’s pressure and the volume or radius of the measuring cell
3.1.3
connecting line
cable that connects the control unit to the probe, delivers fluid and/or gas pressure in the measuring
and guard cells
3.1.4
pressuremeter test pocket
circular cylindrical cavity formed in the ground to receive a pressuremeter probe (3.1.1)
Note 1 to entry: See Annex C.
3.1.5
pressuremeter borehole
borehole in which pressuremeter test pockets (3.1.4) with circular cross sections are made in the ground,
and into which the pressuremeter probe (3.1.1) is to be placed
Note 1 to entry: See Figure 1.
3.1.6
Ménard pressuremeter test
process during which a pressuremeter probe (3.1.1) is inflated in the pressuremeter test pocket (3.1.4) and
the resulting pocket expansion is measured as a function of time and pressure increments according to
a defined programme
Note 1 to entry: See Figure 4.
3.1.7
pressuremeter sounding
sequence of Ménard pressuremeter tests (3.1.6) executed from the same station in the pressuremeter
borehole (3.1.5)
3.1.8
pressure reading
pressure as read at the control unit (CU) elevation in the fluid and/or gas circuit supplying the
measuring cell
3.1.9
pressure loss
difference between the pressure inside the probe and the pressure applied to the pressuremeter test
pocket (3.1.4) wall
3.1.10
volume loss
volume readings on the control unit while probe is kept at constant external diameter
Note 1 to entry: They are due to system compressibility (including membrane, probe, tubing, fluid and control
unit).
3.1.11
raw pressuremeter curve
graphical plot of the injected volumes recorded at time 60 s, noted V , versus the applied pressure at
each pressure step, p
r
2 © ISO 2021 – All rights reserved

ISO 22476-4:2021(E)
3.1.12
corrected pressuremeter curve
graphical plot of the corrected volumes V or radial displacements versus the corrected pressure p
i
Note 1 to entry: See Figure 5.
3.1.13
pressuremeter creep
difference in volumes recorded at 60 s and at 30 s at each pressure step: V – V = V
60 30 60/30
3.1.14
corrected pressuremeter creep curve
graphical plot of the corrected pressuremeter creep versus the corrected applied pressure at each
,
pressure step
Note 1 to entry: See Figure 5.
3.1.15
pressuremeter log
graphical report of the results of the pressuremeter sounding (3.1.7), together with all the information
gathered during the drilling
Note 1 to entry: See F.3.
3.1.16
Ménard pressuremeter modulus
modulus obtained from the section between (p V ) and (p V ) of the pressuremeter curve
1, 1 2, 2
Note 1 to entry: See Figure D.6.
3.1.17
Ménard pressuremeter limit pressure
pressure at which the volume of the pressuremeter test pocket (3.1.4) at the depth of the measuring cell
has doubled its original volume
Note 1 to entry: See Figure D.5.
3.1.18
pressuremeter creep pressure
pressure defined as the intersection of two straight lines fitted on the creep curve
Note 1 to entry: See Figure D.4.
3.1.19
operator
person who carries out the test
3.1.20
casing
lengths of tubing inserted into a borehole to prevent the hole caving in or to prevent the loss of flushing
medium to the surrounding formation, above pocket location
3.2 Symbols
For the purposes of this document, the symbols in Table 2 apply:
Table 2 — Symbols
Symbol Description Unit
3 3
A, B Parameters for reciprocal curve fitting method cm , cm /MPa
ISO 22476-4:2021(E)
Table 2 (continued)
Symbol Description Unit
A to A Parameters for hyperbolic curve fitting methods variable
1 6
a Apparatus volume loss coefficient cm /MPa
Parameters of power law type interpolation for the probe pressure loss correc-
b, c variable
tion
d, e Parameters of linear type interpolation for the probe volume loss correction variable
Outside diameter of the central measuring cell, including any additional protec-
d mm
c
tion such as a slotted tube
d Outside diameter of the inner part of the probe with slotted tube mm
ci
d Outside diameter of the guard cells mm
g
d Inside diameter of the calibration cylinder used for the volume loss calibration mm
i
Outside diameter of the central measuring cell during expansion as read on the
d cm
r
CU, before data correction
d Drilling tool diameter mm
t
E Ménard pressuremeter modulus MPa
M
K Factor to determine the differential pressure for tri-cell probes -
Length of the central measuring cell of the probe, when the cell membrane is
l mm
c
fixed on the probe steel core
l Length of each guard cell mm
g
l Length along the tube axis of the slotted section of the slotted tube mm
m
l Length of the calibration cylinder used for the volume loss calibration mm
p
l Length of the cover mm
t
m Parameter of power law type interpolation for the probe pressure loss correction -
m Minimum value, strictly positive, of the m slopes cm /MPa
E i
Slope of the corrected pressuremeter curve between the two points with coordi-
m cm /MPa
i
nates (p , V ) and (p , V )
i-1 i-1 i i
p Pressure applied to the ground after correction MPa
p Fluid or gas pressure in the measuring cell of the pressuremeter probe. MPa
c
p Correction for probe pressure loss MPa
e
p Pressure at the origin of the segment exhibiting the slope m MPa
E E
p' Pressure at the end of the segment exhibiting the slope m MPa
E E
p Ultimate pressure loss of the probe MPa
el
p Pressuremeter creep pressure MPa
f
p Pressure in the guard cells, read at the CU transducer elevation -
g
Hydrostatic pressure between the control unit indicator and the central measur-
p MPa
h
ing cell of the pressuremeter probe
p Pressuremeter corrected pressure MPa
i
p Ménard pressuremeter limit pressure of the ground MPa
lM
Ménard pressuremeter limit pressure as extrapolated by the double hyperbolic
p MPa
lMDH
method
p Ménard pressuremeter limit pressure as extrapolated by the hyperbolic method MPa
lMH
Ménard pressuremeter limit pressure as extrapolated by the reciprocal curve
p MPa
lMR
method
p Pressure loss of the central measuring cell membrane for a specific expansion MPa
m
Pressure in the measuring cell fluid or gas circuit, read at the CU transducer
p MPa
r
elevation
p Target pressure for each pressure step according to loading program MPa
t
4 © ISO 2021 – All rights reserved

ISO 22476-4:2021(E)
Table 2 (continued)
Symbol Description Unit
p Pressuremeter horizontal at rest pressure MPa
p Corrected pressure at the origin of the pressuremeter modulus pressure range MPa
p Corrected pressure at the end of the pressuremeter modulus pressure range MPa
t Time s
t Time the loading pressure level is held s
h
u Pore water pressure in the ground at the depth of the test MPa
s
Value, after zeroing and data correction, of the volume injected in the central
V cm
measuring cell and measured 60 s after starting a pressure step
Original volume of the central measuring cell, including the slotted tube, if appli-
V cm
c
cable
Value, after data correction, of the volume injected in the central measuring cell
V cm
E
for pressure p
E
Value, after data correction, of the volume injected in the central measuring cell
V’ cm
E
for pressure p’
E
V Correction for volume loss of the whole equipment
e
V Corrected volume cm
i
Value, after data correction, of the volume injected in the central measuring cell
V cm
L
when the original volume of the pressuremeter cavity has doubled
V The average corrected volume between V and V cm
m 1 2
Volume corresponding is the intercept on the volume axis of the straight line best
V fitting the data points on the p-V curve obtained in the volume loss calibration cm
p
test (see Figure B.2)
V Volume injected in the probe as read on the CU, before data correction cm
r
V Volume of the central measuring cell including the slotted tube cm
t
V Corrected volume at the origin of the pressuremeter modulus pressure range cm
V Corrected volume at the end of the pressuremeter modulus pressure range cm
Volume injected in the central measuring cell as read 30 s after the beginning of
V cm
the pressure step
Volume injected in the central measuring cell as read 60 s after the beginning of
V cm
the pressure step
Injected volume change from 30 s to 60 s after reaching the pressure step, also
V cm
60/30
called pressuremeter creep
V 60 s injected volume change between two successive pressure steps cm
60/60
z Elevation, positively counted above datum m
Elevation of the pressure measuring device for the fluid and/or gas injected in
z m
CU
the probe
z Elevation of the ground surface at the location of the pressuremeter sounding m
N
z Elevation of the measuring cell centre during testing m
p
Elevation of the ground water table (or free water surface in a marine or river
z m
w
environment)
β Coefficient used to determine the pressuremeter modulus pressure range ---
γ Unit weight of ground at the time of testing kN/m
γ Unit weight of the liquid injected in the central measuring cell kN/m
i
γ Unit weight of water kN/m
w
Δp Loading pressure increment MPa
Δp Initial pressure increment MPa
r Radius of the measuring cell for transducer i m
i
ISO 22476-4:2021(E)
Table 2 (continued)
Symbol Description Unit
Δt Duration to achieve pressure step i s
i
δV Tolerance for volume measurement cm
-1
λ Rate of change of pressure head of gas at p per metre depth m
g k
ν Poisson’s ratio -
σ Total horizontal stress in the ground at test elevation kPa
hs
σ Total vertical stress in the ground at test depth kPa
vs
4 Equipment
4.1 General description
The pressuremeter shown schematically in Figure 2 shall include:
— the pressuremeter probe;
— the string of rods to handle the probe;
— the control unit (CU);
— the connecting lines between the control unit and the probe.
Some means of measuring the depth of the test with appropriate measurement error shall be provided
(see also Annex E).
4.2 Pressuremeter probe
4.2.1 General
The probe shall be made up of cylindrical cells of circular cross-section along the same axis (see
Figure 2). The probe shall consist of a hollow steel core with passages to inject the proper fluids to
inflate the cells. The steel core, on its outside curved surface, shall usually bear a network of grooves
which uniformly distribute the liquid (if relevant) in the measuring cell under the membrane, applying
a uniform pressure on the pressuremeter test pocket wall. The top of the core shall be threaded and
coupled to the string of rods handling the probe from ground level.
If the measuring cell has slenderness at least equal to 6, the probe may be mono-cell. Conversely the
probe may be tri-cell to respect this criterion. A central measuring cell membrane shall isolate the fluid
in the central measuring cell from the gas of the guard cells.
NOTE 1 Compliance with this criterion ensures that the stress field is two-dimensional.
The central measuring cell may be:
— covered by the cover creating guard cell (tri-cell G type probe);
— covered by the cover with specific membranes for guard cells (tri-cell E type probe);
— covered by the cover without guard cells (mono-cell type).
All probes can be equipped for volumetric measurement or by radial transducer or any device providing
a reliable measure of either probe volume or radius. Pressure can be measured at control unit level or
at probe level.
6 © ISO 2021 – All rights reserved

ISO 22476-4:2021(E)
a) Tri-cell probe, G type, with measurement of b) Tri-cell probe, E type, with measurement of
volume of the measuring cell volume of the measuring cell
c) Mono-cell probe, with measurement of radial d) Tri-cell probe, with measurement of radial
displacement (optional) displacement
Key
1a pressurization, differential pressurization and injection devices
1b pressure and volume measuring devices
1c acquisition, storage and printing out of the data (required for CU type B and C)
2 connecting lines: 2a line for liquid injection
2b line for gas injection
3 depth measurement system 6 ground
4 rods 7 pressuremeter test pocket
5 pressuremeter probe 8 hollow probe body
ISO 22476-4:2021(E)
5a upper guard cell 9 probe rod coupling
5b central measuring cell 10 transducers
5c lower guard cell
Figure 2 — Diagram of a Ménard pressuremeter
If expansion is followed by the volume of the measuring cell, the measuring cell shall be inflated by
injecting a liquid of low compressibility.
NOTE 2 Alternatively air can be used to inflate the measuring cell and the expansion followed by displacement
transducers.
Three types of pressuremeter probes shall be used depending of ground type and conditions according
to Annex C:
— hollow probe body with a flexible cover;
— hollow probe body with a flexible cover and an additional more rigid protection;
— hollow probe body with a flexible cover and a slotted steel tube.
These probes are respectively described in Figure 3 a) and Figure 3 b) and their geometrical features
are given in Table A.1.
The pressuremeter probe shall be capable of a volumetric expansion such as to enable assessing the
Ménard pressuremeter limit pressure within its pressure capabilities.
NOTE 3 For 60 mm probes and probes in 60 mm slotted tubes, 200 + V can be used, where 200 and V are in
c c
cm .
NOTE 4 For other dimensions of tri-cell probes and for mono-cell probes, a specific assessment can be made.
4.2.2 Probe with flexible cover
The probe includes:
— one measuring cell, with an outside diameter d and a minimum length l , which shall expand radially
c c
in a pocket and shall apply a uniform pressure to the pocket wall;
— two guard cells if applicable with an outside diameter d and a length l located above and below
g g
the central measuring cell. These cells shall be designed to apply to the pocket wall a pressure close
to, but not greater than, the pressure induced by the central measuring cell. These cells should be
inflated by gas pressure.
The tri-cell probe should be fitted with a central measuring cell membrane and a flexible cover sleeve.
The membrane and the flexible cover shall be fixed to the steel core with sealing system in order to
avoid any leakage or pressure loss.
The flexible cover can be reinforced by textile or metallic canvas.
4.2.3 Probe with flexible cover and an additional more rigid protection
A flexible protection made of thin plastic or steel strips, either overlapping (up to half-way) or isolated,
running between fixing rings may be added over the cover.
NOTE The flexible protection can be added to reduce damage to the cover from sharp fragments protruding
from the pocket wall.
8 © ISO 2021 – All rights reserved

ISO 22476-4:2021(E)
4.2.4 Probe with flexible cover and slotted tube
This probe shall consist of two parts:
— an inner part corresponding to previously described probes, and
— an outer part which shall be made of a slotted steel tube (see Figure 3). When this slotted tube
is pushed or driven into the soil it shall be fitted with an extension pipe ending with a point or a
cutting shoe.
The outside steel tube shall carry at least 6 axial slots, evenly distributed round the circumference
[Figure 3 b)].
The diameter of the slotted tube shall be verified at intervals appropriate to the use the probe has
received, so that it remains compliant with tool diameter (see C.2.2).
The slotted tube should be kept clean, so that it is able to recover its original shape and size.
The assembly within the slotted tube shall be located so as to allow the probe to expand radially with
a minimum of resistance. The mid plane of the measuring cell shall correspond to the mid plane of the
slots.
ISO 22476-4:2021(E)
a) pressuremeter probe with flexible cover b) pressuremeter probe with slotted tube
Key
1 hollow probe body 6 measuring cell drain outlet
2 measuring cell membrane 7 slotted tube
3 external sleeve or flexible cover 8 rods
4 liquid inlet to the measuring cell 9 probe-rod coupling
5 gas inlet to the guard cell
Figure 3 — Description of the pressuremeter probe
4.3 Connecting lines and injected fluid
The flexible lines shall connect the pressure and volume control unit to the probe. They shall convey the
liquid to the measuring cell and the gas to the guard cells. They may be parallel or coaxial. When the
lines are coaxial the central line shall convey the liquid and the outer line the gas.
10 © ISO 2021 – All rights reserved

ISO 22476-4:2021(E)
The liquid injected into the measuring cell is either water or a liquid of similar viscosity and shall not
freeze under the conditions of use.
The injected fluid and inner diameter of the connecting lines shall be selected in order to transmit
the fluid from the CU to the probe in a time acceptable for pressure step to apply to the ground. The
increment of volume V should be lower than 30 cm at the ultimate pressure loss of the probe p
60/30 el
during central membrane pressure loss test.
NOTE Additives such as ethylene glycol increase notably the viscosity of the fluid and therefore the time to
transmit the fluid from the CU to the probe is increased. Alternative fluid like oil can also be chosen.
4.4 Pressure and volume control unit
4.4.1 General
The control unit shall include:
— equipment to pressurize, and so to inflate the probe, and to maintain constant pressures as required
during the test;
— equipment to maintain an appropriate pressure difference between the central measuring cell and
the guard cells, if relevant;
— device which permits, according to the type defined in Table 1, the reading and recording of the
parameters to be measured: time, pressure and volume.
Table 3 — Types of pressuremeter control unit
Type of control unit Type of test regulation Type of reading and recording
A manual manual
B manual automatic
C automatic automatic
The control unit shall control the probe cell expansion and permit the simultaneous reading of liquid
and/or gas pressures and injected liquid volume or radius of the measuring cell as a function of time.
The pressurizing device shall allow:
— reaching the pressuremeter limit pressure or a pressure p at least equal to the maximum pressure
r
defined for the test;
— holding constant each loading pressure level in the measuring cell and in the guard cells during the
set time;
— implementing a pressure increment of 0,5 MPa in less than 20 s as measured on the control unit;
— controlling the pressure difference between the measuring cell and the guard cells;
— injecting a volume of liquid in the measuring cell larger than at least its volume at rest V , i.e. 700 cm
c
for a 60 mm pressure
...