ISO 22476-5:2023

Geotechnical investigation and testing — Field testing — Part 5: Prebored pressuremeter test

This document is applicable to pressuremeter tests using cylindrical flexible probes placed in pre-existent boreholes using testing procedures other than the Menard procedure. Pressuremeter tests following the Menard procedure are provided in ISO 22476-4. NOTE A high-pressure flexible pressuremeter probe which contains transducers for the measurement of radial displacements is also known as flexible dilatometer probe or high-pressure dilatometer probe. This document applies to tests performed in any kind of grounds, starting from soils, treated or untreated fills, hard soils and soft rocks, up to hard and very hard rocks, either on land or offshore. The parameters derived from this test can include stiffness, strength, initial in-situ stress state and consolidation properties.

Reconnaissance et essais géotechniques — Essais en place — Partie 5: Essai au pressiomètre en préforage

Ce document s’applique aux essais au pressiomètre utilisant des sondes flexibles cylindriques placées dans des trous de forage pré-existants, réalisés selon des procédures autres que la procédure Ménard. Les essais au pressiomètre selon la procédure Ménard sont disponibles dans l’ISO 22476-4. NOTE Une sonde pressiométrique flexible haute pression qui comporte des capteurs destinés à la mesure des déplacements radiaux est également appelée dilatomètre flexible ou dilatomètre haute pression. Ce document s’applique aux essais réalisés dans tout type de terrain, depuis des sols, des remblais traités ou non traités, des sols durs et des roches tendres, jusqu’à des roches dures et très dures, à terre ou en mer. Les paramètres déduits de cet essai peuvent inclure le module, la résistance, l’état de contrainte in situ initial et des propriétés de consolidation.

General Information

• Status: Published
• Publication Date: 26-Mar-2023
• ICS: 93.020 - Earthworks. Excavations. Foundation construction. Underground works
• Technical Committee: ISO/TC 182 - Geotechnics
• Drafting Committee: ISO/TC 182/WG 8 - Borehole expansion tests
• Current Stage: 6060 - International Standard published
• Start Date: 27-Mar-2023
• Due Date: 02-Feb-2023
• Completion Date: 27-Mar-2023

Relations

• Revises: ISO 22476-5:2012 - Geotechnical investigation and testing — Field testing — Part 5: Flexible dilatometer test
• Effective Date: 07-Apr-2018

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 22476-5
Second edition
2023-03
Geotechnical investigation and
testing — Field testing —
Part 5:
Prebored pressuremeter test
Reconnaissance et essais géotechniques — Essais en place —
Partie 5: Essai au pressiomètre en préforage
Reference number
ISO 22476-5:2023(E)
© ISO 2023

---------------------- Page: 1 ----------------------
ISO 22476-5:2023(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2023
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
ii
  © ISO 2023 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 22476-5:2023(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 and abbreviations . 5
4 Equipment . 6
4.1 General . 6
4.2 Pressuremeter probe . 10
4.3 Connecting lines . 10
4.4 Control unit (CU) . 10
4.5 Measurement and control accuracy . 11
4.5.1 Time . 11
4.5.2 Pressure and expansion . . 11
4.5.3 Display of readings . 11
4.5.4 Expansion calibration cylinder . 11
5 Test procedures .11
5.1 Assembly of parts. 11
5.2 Calibration of the testing device and corrections of readings .12
5.3 Pressuremeter test pocket and probe placing .12
5.4 Test execution . .12
5.4.1 Test loading programmes .12
5.4.2 Reference loading programmes . 13
5.4.3 Readings and recordings before and during the test .13
5.5 End of test . 14
5.6 Backfilling of borehole . 14
5.7 Safety requirements . 14
6 Test results . .14
6.1 General . 14
6.2 Corrected pressure, radial displacement and volume . 15
6.3 Apparent pressuremeter moduli . 15
6.4 Results . . 16
6.4.1 Determination of moduli . 16
6.4.2 Reference loading programme A . 16
6.4.3 Reference loading programme B. 17
6.4.4 Reference loading programme C . 18
7 Reporting .19
7.1 General . 19
7.2 Contents . 19
7.3 Presentation of test results . 21
Annex A (normative) Calibration and corrections .22
Annex B (informative) Performing the test .30
Annex C (normative) Accuracy and uncertainties .36
Bibliography .37
iii
© ISO 2023 – All rights reserved

---------------------- Page: 3 ----------------------
ISO 22476-5:2023(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 22476-5:2012), which has been technically
revised.
The main changes are as follows:
— the title of the part has been modified;
— a reference loading programme with cyclic loading has been added;
— calibration procedures have been developed.
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.
iv
  © ISO 2023 – All rights reserved

---------------------- Page: 4 ----------------------
INTERNATIONAL STANDARD ISO 22476-5:2023(E)
Geotechnical investigation and testing — Field testing —
Part 5:
Prebored pressuremeter test
1 Scope
This document is applicable to pressuremeter tests using cylindrical flexible probes placed in pre-
existent boreholes using testing procedures other than the Menard procedure.
Pressuremeter tests following the Menard procedure are provided in ISO 22476-4.
NOTE A high-pressure flexible pressuremeter probe which contains transducers for the measurement of
radial displacements is also known as flexible dilatometer probe or high-pressure dilatometer probe.
This document applies to tests performed in any kind of grounds, starting from soils, treated or
untreated fills, hard soils and soft rocks, up to hard and very hard rocks, either on land or offshore.
The parameters derived from this test can include stiffness, strength, initial in-situ stress state and
consolidation properties.
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.
EN 16228-1, Drilling and foundation equipment – safety – Part 1:Common requirements
EN 16228-2, Drilling and foundation equipment – safety – Part 2: Mobile drill rigs for civil and geotechnical
engineering, quarrying and mining
ISO 10012, Measurement management systems — Requirements for measurement processes and measuring
equipment
ISO 14689, Geotechnical investigation and testing — Identification, description and classification of rock
ISO 22475-1, Geotechnical investigation and testing — Sampling methods and groundwater measurements
— Part 1: Technical principles for the sampling of soil, rock and groundwater
ISO 22476-4, Geotechnical investigation and testing — Field testing — Part 4: Prebored pressuremeter test
by Ménard procedure
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 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/
1
© ISO 2023 – All rights reserved

---------------------- Page: 5 ----------------------
ISO 22476-5:2023(E)
3.1.1
pressuremeter probe
cylindrical flexible probe which can be expanded by the application of hydraulic pressure and/or
pressurised gas
Note 1 to entry: Pressuremeter probes contains means of measurement of its radial displacements or volume.
3.1.2
flexible dilatometer probe
high-pressure dilatometer probe
high-pressure flexible pressuremeter probe which contains transducers for the measurement of radial
displacements
3.1.3
pressuremeter control unit
set of suitable devices capable of supplying fluid and/or gas pressure to the probe, to control and take
readings of the probe’s pressure, radial displacements or volume of the measuring cell
3.1.4
connecting line
cable that connects the control unit to the probe, delivers fluid and/or gas pressure in the measuring
and guard cells
3.1.5
pressuremeter test pocket
circular cylindrical cavity formed in the ground to receive a pressuremeter probe (3.1.1)
3.1.6
pressuremeter test
process of expanding the pressuremeter probe so as to pressurize the flexible membrane against the
pocket wall and so measure pressure, radial displacements or volume as a function of time during the
expansion test
Note 1 to entry: See Figure 1.
3.1.7
pressuremeter sounding
series of pressuremeter tests in a borehole
3.1.8
seating pressure
pressure during the expansion of the pressuremeter at which the pressuremeter membrane contacts
the pocket wall
3.1.9
controlling parameter
variable used to define the loading programme of the test according to a pre-determined programme
and recorded in the control unit
Note 1 to entry: This variable can be the pressure, the radius displacement or the injected volume.
3.1.10
radial displacement
change in pressuremeter probe radius/diameter or in cavity wall displacement
3.1.11
pressuremeter curve
graphical plot of pressure versus the associated cavity wall displacement or measuring cell volume
2
  © ISO 2023 – All rights reserved

---------------------- Page: 6 ----------------------
ISO 22476-5:2023(E)
3.1.12
pressuremeter shear modulus
G
PBP
shear modulus obtained from the pressuremeter curve
Note 1 to entry: See 6.3
3
© ISO 2023 – All rights reserved

---------------------- Page: 7 ----------------------
ISO 22476-5:2023(E)
Key
1 ground surface
2 borehole wall
3 pocket
4 expanding pressuremeter probe
P applied pressure
A-A axial section
B-B cross section
Figure 1 — Example of a prebored pressuremeter test
4
  © ISO 2023 – All rights reserved

---------------------- Page: 8 ----------------------
ISO 22476-5:2023(E)
3.1.13
depth of test
distance between the ground level and the centre of the expanding length of the pressuremeter probe
measured along the borehole axis
Note 1 to entry: See Figure 2.
3.1.14
operator
qualified person who carries out the test
3.1.15
phase
section of the loading or expansion program characterized by a controlling parameter, a loading rate
and a loading direction
3.1.16
loop
sequence of the loading or expansion program including at least an unloading phase and a reloading
phase, and possibly an intermediate hold phase
3.2 Symbols and abbreviations
For the purposes of this document, the symbols in Table 1 apply.
Table 1 — Symbols
Symbol Description Unit
-1
a Corrected equipment radial displacement or volume mm.MPa
loss coefficient, taking into account calibration cylinder
or
self-deformability
3 -1
cm .MPa
-1
a Raw equipment radial displacement or volume loss mm.MPa
r
coefficient
or
3 -1
cm .MPa
-1
a Radial displacement or equivalent volume loss taking into mm.MPa
cc
account calibration cylinder self-deformability
or
3 -1
cm .MPa
d Calibration cylinder inside diameter mm
cc
d Initial external diameter of the pressuremeter probe mm
c
E A Young modulus derived from a prebored pressuremeter MPa
PBP
test
G Shear modulus MPa
G First loading pressuremeter shear modulus MPa
L1
G Pressuremeter shear modulus MPa
PBP
G A reloading pressuremeter shear modulus MPa
Ri
G Apparent shear modulus of the equipment or system during MPa
sys
unloading-reloading loops
G An unloading pressuremeter shear modulus MPa
Ui
G An unloading/reloading pressuremeter shear modulus MPa
URi
k Creep parameter in reference loading programme C mm
f
L Expanding length of the pressuremeter probe mm
FD
p Corrected pressure MPa
5
© ISO 2023 – All rights reserved

---------------------- Page: 9 ----------------------
ISO 22476-5:2023(E)
TTabablele 1 1 ((ccoonnttiinnueuedd))
Symbol Description Unit
p Constant full relief pressure for loops in reference loading MPa
1.1
programme A
p Pressure loss associated with membrane stiffness
e
p Corrected reversal pressure before loop i MPa
i
p Average corrected pressure in reference loading programme MPa
mean
D
p Minimum corrected pressure in reference loading pro- MPa
min
gramme D
p Maximum corrected pressure in reference loading pro- MPa
max
gramme D
p Pressure as read at the measuring unit MPa
r
p Seating pressure MPa
s
r Corrected radius mm
r Corrected radius at time t in reference loading programme mm
1 1
C
r Corrected radius at time t in reference loading programme mm
2 2
C
r Radius correction mm
e
r Nominal cavity radius mm
s
t Time min
T Period in reference loading programme D min
t Time 1 in reference loading programme C min
1
t Time 2 in reference loading programme C min
2
3
ΔV Corrected injected volume cm
3
ΔV Injected volume correction cm
e
3
ΔV Injected volume, as read at the control unit cm
r
3
V Total volume cm
z Test depth m
δ Corrected radial displacement mm
δ Radial displacement correction mm
e
δ Radial displacement, as read at the control unit mm
r
δ Radial displacement corresponding to the seating pressure mm
s
Δd Increase of diameter, as read at the control unit mm
r
Δd Corrected diameter increase mm
Δp Pressure increment, as read at the control unit MPa
r
Δp Corrected pressure increment MPa
ε Cavity strain -
c
ν Poisson’s ratio -
4 Equipment
4.1 General
The test with the pressuremeter is performed by the expanding of a pressuremeter membrane placed
in the ground (see Figure 1). The pressure and the associated expansion of the probe are measured and
recorded so as to obtain a pressure-expansion relationship for the ground as tested.
6
  © ISO 2023 – All rights reserved

---------------------- Page: 10 ----------------------
ISO 22476-5:2023(E)
The equipment to carry out pressuremeter tests shall consist of the components shown in Figure 2.
The following components are mandatory:
— pressuremeter probe (no. 8 in Figure 2);
— connecting line (no. 6 in Figure 2);
— signal cable (no. 5 in Figure 2);
— displacement or volume measuring unit (no. 2 in Figure 2);
— pressure control unit (no. 3 in Figure 2);
— pressure source (no. 4 in Figure 2).
— setting rods (no.1 in Figure 2).
The following components may be added to allow orientation of the instrument if needed:
— data logger (no. 9 in Figure 2);
— sediment collection tube (no. 14 in Figure 3);
— pore pressure measuring system;
— accelerometer or geophones to perform shear wave velocity measurements.
7
© ISO 2023 – All rights reserved

---------------------- Page: 11 ----------------------
ISO 22476-5:2023(E)
Key
1 setting rods 6 connecting line
2 displacement or volume measuring unit 7 probe rode coupling sediment collection tube
3 pressure control unit 8 pressuremeter probe
4 pressure source 9 data logger
5 signal cable z test depth
Figure 2 — Schematic diagram of pressuremeter equipment
8
  © ISO 2023 – All rights reserved

---------------------- Page: 12 ----------------------
ISO 22476-5:2023(E)
a) Tri-cellular or monocellular b) Monocellular probe with c) Monocellular probe with
probe with expansion followed displacement measured displacement measured
through the volume of central inside the membrane at the cavity wall
cell
Key
1 control unit (CU): 1a pressurization, differential pressurization (if any) and
injection devices
 1b pressure and displacement or 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
 2c signal cable
3 depth measurement system
4 setting rods
5 pressuremeter probe 5a upper guard cell
 5b central measuring cell
 5c lower guard cell
6 ground
7 pressuremeter test pocket
8 probe body, hollow
9 probe rod coupling
10 and 11 displacement transducers
12 metal insert at the extremities
of the displacement transducers
13 membrane clamping ring
14 sediment collection tube
15 pressure transducer (if applicable)
16 compass (if applicable)
Figure 3 — Sketch of pressuremeter probes
9
© ISO 2023 – All rights reserved

---------------------- Page: 13 ----------------------
ISO 22476-5:2023(E)
Preparation of pressuremeter test pocket shall be performed according to ISO 22476-4. The annular
space between borehole wall and the probe, if any, shall be chosen taking into account the measuring
range of the displacement transducers if any. Drilling parameters should be recorded according to
ISO 22476-15. Borehole log should be recorded according to ISO 22475-1 and ISO 14689.
4.2 Pressuremeter probe
The probe expansion shall be monitored by radial displacement [see Figure 3 b) and c)] or volume
measurement [see Figure 3 a)].
The probe shall have a cover in a shape of monocellular or be tricellular. When small strain measurement
(as defined in EN 1997-2) is needed, local displacement measurement can be implemented in the probe.
Radial displacements shall be measured by electrical transducers on two or more points, placed in the
vicinity of the mid plane [see Figure 3 b) and c)].
NOTE The arrangement shown in Figure 3 a) and b) with measurement at the inner wall of the membrane is
primarily used in soils. The arrangement shown in Figure 3 c) with measurement on inserts that penetrate the
membrane and directly bear on the cavity walls is primarily used in rocks.
In arrangement shown in Figure 3 a) and b), because membrane compression influences the readings of
pressure and displacement, proper corrections shall be determined by corresponding calibration (see
A.3).
The slenderness of the pressuremeter probe (ratio between expanding length L and initial external
FD
diameter d ) shall at least be equal to 6.
c
If included, pore pressure may be measured in the mid plane of the probe.
4.3 Connecting lines
The pressure connecting line and signal cable connect the control unit to the probe. The pressure
connecting line conveys the fluid to the probe and may be either parallel or coaxial with the signal
cable.
The injected fluid and inner diameter of the connecting lines shall be selected so that the pressure
differential between the CU and the probe remains limited.
4.4 Control unit (CU)
The control unit shall control the probe expansion and permit the reading of liquid or gas pressure and
displacement or volume as a function of time.
The pressurizing system (3 and 4 in Figure 2) shall allow:
— reaching a pressure defined by the project;
— implementing a pressure increment of 0,5 MPa as measured on the control unit in less than 20 s;
— stopping the injection when necessary.
The control unit shall include:
— equipment to apply the controlling parameters, and so to inflate or deflate 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 any;
— a device that allows, according to the type defined in Table 2, the reading and recording of the
parameters to be measured: time, pressure and displacement or volume.
10
  © ISO 2023 – All rights reserved

---------------------- Page: 14 ----------------------
ISO 22476-5:2023(E)
Table 2 — Types of pressuremeter control unit
Type of control unit Type of test control Type of reading Type of recording
A manual manual manual
B manual automatic automatic
C automatic automatic automatic
Some means of measuring the depth of the test with appropriate accuracy shall be provided.
4.5 Measurement and control accuracy
4.5.1 Time
The accuracy of the device used to measure time shall be in accordance with Annex C.
4.5.2 Pressure and expansion
The pressure measuring devices for the liquid or for the gas in the measuring cell shall be located:
— at least in the control unit;
— if relevant, also inside the probe, in this case at less than 1 m above the centre of the measuring cell.
The maximum uncertainty of measurement of the devices measuring pressure and probe expansion
shall be as specified in Annex C.
4.5.3 Display of readings
On site, the pressure control and probe expansion measuring units shall give a simultaneous and
instantaneous display of the following readings: time, pressure of the fluid injected into the probe and
radial displacements or injected volume.
4.5.4 Expansion calibration cylinder
The main dimensions of the steel calibration cylinder serving the calibration for membrane compression
and additional effects shall be as follows:
— a known inside diameter which closely fits the deflated instrument;
— a thickness appropriate to the maximum pressure to be applied;
— a length appropriately greater than the expanding length of the instrument.
5 Test procedures
5.1 Assembly of parts
The cover, the membrane and possibly the rigid protection or the slotted tube if required shall be
selected according to the planned loading programme and type of the ground in which the probe is to
be used.
Then the probe shall be linked to the control unit through the connecting lines and cables. The whole
system shall be filled with working fluid and purged to remove air bubbles if relevant.
11
© ISO 2023 – All rights reserved

---------------------- Page: 15 ----------------------
ISO 22476-5:2023(E)
5.2 Calibration of the testing device and corrections of readings
Before testing, the operator shall make sure that:
— all measuring components have been calibrated according to ISO 10012;
— calibration of the whole system has been performed according to Annex A and reading corrections
are available.
Copies of the calibration documents shall be available on request.
5.3 Pressuremeter test pocket and probe placing
The test location is usually determined from design requirements. The position of the borehole into
which the probe is to be inserted shall be marked on a drawing and identified by its location details.
The pocket shall be drilled and the pressuremeter probe placed in the test location with the minimum
of disturbance to the borehole wall to be tested.
The pocket and the probe placing shall be performed, and samples shall be taken according to
ISO 22476-4, with the exception of techniques involving ground displacement (e.g. pushed probe, driven
slotted tube).
NOTE Pressuremeter testing for which placement of probes involves ground displacement is dealt by
ISO 22476-8.
If necessary, the instrument may be orientated in the
...

ISO/TC 182
Date: 2022-10-24
ISO/DISFDIS 22476-5:2022(E)
Date: 2022-12-07
ISO/TC182/WG08TC 182/WG 08
Secretariat: BSI

Geotechnical investigation and testing — Field testing — Part 5: Prebored
pressuremeter test
Reconnaissance et essais géotechniques — Essais en place — Partie 5: Essai au pressiomètre en
préforage

---------------------- Page: 1 ----------------------
Error! Reference source not found.
COPYRIGHT PROTECTED DOCUMENT
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. + 41 22 749 01 11
Fax + 41 22 749 09 47
[e-mail]
www.iso.org
ii Error! Reference source not found.

---------------------- Page: 2 ----------------------
ISO/FDIS 22476-5:2022(E)
Contents
Foreword . viii
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 2
3.1 Terms and definitions . 2
Figure 1 — Example of a prebored pressuremeter test . 5
3.2 Symbols and abbreviations . 6
Table 1 — Symbols . 6
4 Equipment . 8
4.1 General . 8
Figure 2 — Schematic diagram of pressuremeter equipment . 10
Figure 3 — Sketch of pressuremeter probes  . 11
4.2 Pressuremeter probe . 12
4.3 Connecting lines . 12
4.4 Control unit (CU) . 12
Table 2 — Types of pressuremeter control unit . 13
4.5 Measurement and control accuracy . 13
4.5.1 Time . 13
4.5.2 Pressure and expansion . 13
4.5.3 Display of readings . 13
4.5.4 Expansion calibration cylinder . 13
5 Test procedures . 13
5.1 Assembly of parts . 13
5.2 Calibration of the testing device and corrections of readings . 13
5.3 Pressuremeter test pocket and probe placing . 14
5.4 Test execution . 14
5.4.1 Test loading programmes . 14
5.4.2 Reference loading programmes . 15
Figure 4 — Reference loading programmes A, B, C and D . 15
5.4.3 Readings and recordings before and during the test . 16
5.5 End of test . 16
5.6 Backfilling of borehole . 17
5.7 Safety requirements . 17
6 Test results . 17
6.1 General . 17
6.2 Corrected pressure, radial displacement and volume . 17
6.3 Apparent pressuremeter moduli . 18
6.4 Results . 18
6.4.1 Determination of moduli . 18
6.4.2 Reference loading programme A . 19
Table 3 —Pressuremeter shear moduli for reference loading programme A . 19
© ISO 2022 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO/FDIS 22476-5:2022(E)
Figure 5 — Prebored pressuremeter shear moduli GPBP in reference procedure A . 20
6.4.3 Reference loading programme B . 20
Table 4 — Pressuremeter shear moduli for reference loading programme B . 20
Figure 6 — Prebored pressuremeter Shear moduli G in reference procedure B . 21
PBP
6.4.4 Reference loading programme C . 22
Figure 7 — Obtention of the creep parameter k in the reference loading programme C . 23
f
7 Test report . Error! Bookmark not defined.
7.1 General . 23
7.2 Reporting . Error! Bookmark not defined.
7.3 Presentation of test results . 25
Annex A (normative) Calibration and corrections . 26
A.1 Measuring devices . 26
A.2 Pressure correction . 26
A.2.1 Preparation of pressuremeter for membrane pressure loss calibration . 26
A.2.2 Membrane pressure loss calibration . 26
Figure A.1 — Membrane stiffness calibration, a) with radial displacement measurement, b)
with injected volume measurement . 27
A.3 Displacement or volume correction . 27
A.3.1 General . 27
A.3.2 Calibration cylinder(s) . 28
A.3.3 Calibration in the general case . 28
A.3.3.1 Calibration including one single cylinder . 28
Figure A.2 — Determination of the combined correction for membrane compression and
connecting lines dilatation (if relevant) . 30
A.3.3.2 Calibration including several cylinders . 30
Figure A.3 — Set of expansion calibration curves . 31
Figure A.4 — Determination of cavity radial displacement when using several calibration
cylinders (example when probe expansion is followed through its volume) . 32
A.3.4 Additional calibration in case of unloading-reloading loops . 32
Figure A.5 — Determination of the apparent system stiffness G .34
sys
Figure A.6 — Determination of the apparent system stiffness G as a function of the
sys
pressure at the beginning of the unloading-reloading loops . 34
Annex B (normative) Performing the test . 36
B.1 Common elements to reference loading programmes A and B . 36
B.2 Details of reference loading programme A . 36
Figure B.1 — Example of reference loading programme A . 37
B.3 Details of reference loading programme B . 38
Figure B.2 — Example of reference loading programme B . 39
B.4 Details of reference loading programme C . 39
iv © ISO 2022 – All rights reserved.

---------------------- Page: 4 ----------------------
ISO/FDIS 22476-5:2022(E)
Figure B.3 — Example of reference loading programme C . 40
Figure B.4 — Corrected applied pressure in reference procedure C with pressure as
controlling parameter. 41
B.5 Details of reference loading programme D . 41
Figure B.5 — Reference loading programme D . 42
Annex C (normative) Accuracy and uncertainties . 43
C.1 Uncertainties of the measurements . 43
Table C.1 — Maximum allowed uncertainties . 43
C.2 Uncertainties of the tests results . 43
Bibliography. 45
Foreword . vii
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 2
3.1 Terms and definitions . 2
Figure 1 — Example of a prebored pressuremeter test . 5
3.2 Symbols and abbreviations . 6
Table 1 — Symbols . 6
4 Equipment . 8
4.1 General . 8
Figure 2 — Schematic diagram of pressuremeter equipment . 10
Figure 3 — Sketch of pressuremeter probes . 11
4.2 Pressuremeter probe . 12
4.3 Connecting lines . 12
4.4 Control unit (CU) . 12
Table 2 — Types of pressuremeter control unit . 13
4.5 Measurement and control accuracy . 13
4.5.1 Time . 13
4.5.2 Pressure and expansion . 13
4.5.3 Display of readings . 13
4.5.4 Expansion calibration cylinder . 13
5 Test procedures . 13
5.1 Assembly of parts . 13
5.2 Calibration of the testing device and corrections of readings . 13
5.3 Pressuremeter test pocket and probe placing . 14
5.4 Test execution . 14
5.4.1 Test loading programmes . 14
5.4.2 Reference loading programmes . 15
Figure 4 — Reference loading programmes A, B, C and D . 15
5.4.3 Readings and recordings before and during the test . 16
5.5 End of test . 16
5.6 Backfilling of borehole . 17
5.7 Safety requirements . 17
6 Test results . 17
© ISO 2022 – All rights reserved v

---------------------- Page: 5 ----------------------
ISO/FDIS 22476-5:2022(E)
6.1 General . 17
6.2 Corrected pressure, radial displacement and volume . 17
6.3 Apparent pressuremeter moduli . 18
6.4 Results . 18
6.4.1 Determination of moduli . 18
6.4.2 Reference loading programme A . 19
Table 3 — Pressuremeter shear moduli for reference loading programme A . 19
Figure 5 — Prebored pressuremeter shear moduli G in reference procedure A . 20
PBP
6.4.3 Reference loading programme B . 20
Table 4 — Pressuremeter shear moduli for reference loading programme B . 20
Figure 6 — Prebored pressuremeter shear moduli G in reference procedure B . 21
PBP
6.4.4 Reference loading programme C . 22
Figure 7 — Obtention of the creep parameter k in the reference loading programme C . 23
f
7 Reporting . 23
7.1 General . 23
7.2 Contents . 23
Table 5 — General information . 23
7.3 Presentation of test results . 25
Annex A (normative) Calibration and corrections . 26
A.1 Measuring devices . 26
A.2 Pressure correction . 26
A.2.1 Preparation of pressuremeter for membrane pressure loss calibration . 26
A.2.2 Membrane pressure loss calibration . 26
A.3 Displacement or volume correction . 27
A.3.1 General . 27
A.3.2 Calibration cylinder(s) . 28
A.3.3 Calibration in the general case . 28
A.3.3.1 Calibration including one single cylinder . 28
A.3.3.2 Calibration including several cylinders . 30
A.3.4 Additional calibration in case of unloading-reloading loops . 32
Annex B (informative) Performing the test . 36
B.1 Common elements to reference loading programmes A and B . 36
B.2 Details of reference loading programme A . 36
Figure B.1 — Example of reference loading programme A . 37
B.3 Details of reference loading programme B . 38
Figure B.2 — Example of reference loading programme B . 39
B.4 Details of reference loading programme C . 39
Figure B.3 — Example of reference loading programme C . 40
Figure B.4 — Corrected applied pressure in reference procedure C with pressure as
controlling parameter . 41
B.5 Details of reference loading programme D . 41
Figure B.5 — Reference loading programme D . 42
vi © ISO 2022 – All rights reserved.

---------------------- Page: 6 ----------------------
ISO/FDIS 22476-5:2022(E)
Annex C (normative) Accuracy and uncertainties . 43
C.1 Uncertainties of the measurements . 43
Table C.1 — Maximum allowed uncertainties . 43
C.2 Uncertainties of the tests results . 43
Bibliography. 45

© ISO 2022 – All rights reserved vii

---------------------- Page: 7 ----------------------
ISO/FDIS 22476-5:2022(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 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 22476-5:2012), which has been
technically revised.
The main changes are as follows:
— the title of the part has been modified;
— a reference loading programme with cyclic loading has been added;
— calibration procedures have been developed.
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.
viii © ISO 2022 – All rights reserved.

---------------------- Page: 8 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/DIS FDIS 22476--5:2022(E)

Geotechnical investigation and testing — Field testing — Part 5:
Prebored pressuremeter test
Geotechnical investigation and testing — Field testing — Part 5:
Prebored pressuremeter test
1 Scope
This document is applicable to pressuremeter tests using cylindrical flexible probes placed in pre-existent
boreholes using testing procedures other than the Menard procedure.
Pressuremeter tests following the Menard procedure are provided in ISO 22476-4.
NOTE A high-pressure flexible pressuremeter probe which contains transducers for the measurement of radial
displacements i
...

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 22476-5
ISO/TC 182
Geotechnical investigation and
Secretariat: BSI
testing — Field testing —
Voting begins on:
2022-12-21
Part 5:
Voting terminates on:
Prebored pressuremeter test
2023-02-15
Reconnaissance et essais géotechniques — Essais en place —
Partie 5: Essai au pressiomètre en préforage
ISO/CEN PARALLEL PROCESSING
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 SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 22476-5:2022(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. © ISO 2022

---------------------- Page: 1 ----------------------
ISO/FDIS 22476-5:2022(E)
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 22476-5
ISO/TC 182
Geotechnical investigation and
Secretariat: BSI
testing — Field testing —
Voting begins on:
Part 5:
Voting terminates on:
Prebored pressuremeter test
Reconnaissance et essais géotechniques — Essais en place —
Partie 5: Essai au pressiomètre en préforage
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
ISO/CEN PARALLEL PROCESSING
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.
RECIPIENTS OF THIS DRAFT ARE INVITED TO
ISO copyright office
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
CP 401 • Ch. de Blandonnet 8
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
CH-1214 Vernier, Geneva
DOCUMENTATION.
Phone: [phone]
IN ADDITION TO THEIR EVALUATION AS
Reference number
Email: [e-mail]
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 22476-5:2022(E)
Website: www.iso.org
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
Published in Switzerland
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
ii
  © ISO 2022 – All rights reserved
NATIONAL REGULATIONS. © ISO 2022

---------------------- Page: 2 ----------------------
ISO/FDIS 22476-5:2022(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 and abbreviations . 5
4 Equipment . 6
4.1 General . 6
4.2 Pressuremeter probe . 10
4.3 Connecting lines . 10
4.4 Control unit (CU) . 10
4.5 Measurement and control accuracy . 11
4.5.1 Time . 11
4.5.2 Pressure and expansion . . 11
4.5.3 Display of readings . 11
4.5.4 Expansion calibration cylinder . 11
5 Test procedures .11
5.1 Assembly of parts. 11
5.2 Calibration of the testing device and corrections of readings .12
5.3 Pressuremeter test pocket and probe placing .12
5.4 Test execution . .12
5.4.1 Test loading programmes .12
5.4.2 Reference loading programmes . 13
5.4.3 Readings and recordings before and during the test .13
5.5 End of test . 14
5.6 Backfilling of borehole . 14
5.7 Safety requirements . 14
6 Test results . .14
6.1 General . 14
6.2 Corrected pressure, radial displacement and volume . 15
6.3 Apparent pressuremeter moduli . 15
6.4 Results . . 16
6.4.1 Determination of moduli . 16
6.4.2 Reference loading programme A . 16
6.4.3 Reference loading programme B. 17
6.4.4 Reference loading programme C . 18
7 Reporting .19
7.1 General . 19
7.2 Contents . 19
7.3 Presentation of test results . 21
Annex A (normative) Calibration and corrections .22
Annex B (informative) Performing the test .30
Annex C (normative) Accuracy and uncertainties .36
Bibliography .37
iii
© ISO 2022 – All rights reserved

---------------------- Page: 3 ----------------------
ISO/FDIS 22476-5:2022(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 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 22476-5:2012), which has been technically
revised.
The main changes are as follows:
— the title of the part has been modified;
— a reference loading programme with cyclic loading has been added;
— calibration procedures have been developed.
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.
iv
  © ISO 2022 – All rights reserved

---------------------- Page: 4 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 22476-5:2022(E)
Geotechnical investigation and testing — Field testing —
Part 5:
Prebored pressuremeter test
1 Scope
This document is applicable to pressuremeter tests using cylindrical flexible probes placed in pre-
existent boreholes using testing procedures other than the Menard procedure.
Pressuremeter tests following the Menard procedure are provided in ISO 22476-4.
NOTE A high-pressure flexible pressuremeter probe which contains transducers for the measurement of
radial displacements is also known as flexible dilatometer probe or high-pressure dilatometer probe.
This document applies to tests performed in any kind of grounds, starting from soils, treated or
untreated fills, hard soils and soft rocks, up to hard and very hard rocks, either on land or offshore.
The parameters derived from this test can include stiffness, strength, initial in-situ stress state and
consolidation properties.
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.
EN 16228-1, Drilling and foundation equipment – safety – Part 1:Common requirements
EN 16228-2, Drilling and foundation equipment – safety – Part 2: Mobile drill rigs for civil and geotechnical
engineering, quarrying and mining
ISO 10012, Measurement management systems — Requirements for measurement processes and measuring
equipment
ISO 14689, Geotechnical investigation and testing — Identification, description and classification of rock
ISO 22475-1, Geotechnical investigation and testing — Sampling methods and groundwater measurements
— Part 1: Technical principles for the sampling of soil, rock and groundwater
ISO 22476-4, Geotechnical investigation and testing — Field testing — Part 4: Prebored pressuremeter test
by Ménard procedure
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 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/
1
© ISO 2022 – All rights reserved

---------------------- Page: 5 ----------------------
ISO/FDIS 22476-5:2022(E)
3.1.1
pressuremeter probe
cylindrical flexible probe which can be expanded by the application of hydraulic pressure and/or
pressurised gas
Note 1 to entry: Pressuremeter probes contains means of measurement of its radial displacements or volume.
3.1.2
flexible dilatometer probe
high-pressure dilatometer probe
high-pressure flexible pressuremeter probe which contains transducers for the measurement of radial
displacements
3.1.3
pressuremeter control unit
set of suitable devices capable of supplying fluid and/or gas pressure to the probe, to control and take
readings of the probe’s pressure, radial displacements or volume of the measuring cell
3.1.4
connecting line
cable that connects the control unit to the probe, delivers fluid and/or gas pressure in the measuring
and guard cells
3.1.5
pressuremeter test pocket
circular cylindrical cavity formed in the ground to receive a pressuremeter probe (3.1.1)
3.1.6
pressuremeter test
process of expanding the pressuremeter probe so as to pressurize the flexible membrane against the
pocket wall and so measure pressure, radial displacements or volume as a function of time during the
expansion test
Note 1 to entry: See Figure 1.
3.1.7
pressuremeter sounding
series of pressuremeter tests in a borehole
3.1.8
seating pressure
pressure during the expansion of the pressuremeter at which the pressuremeter membrane contacts
the pocket wall
3.1.9
controlling parameter
variable used to define the loading programme of the test according to a pre-determined programme
and recorded in the control unit
Note 1 to entry: This variable can be the pressure, the radius displacement or the injected volume.
3.1.10
radial displacement
change in pressuremeter probe radius/diameter or in cavity wall displacement
3.1.11
pressuremeter curve
graphical plot of pressure versus the associated cavity wall displacement or measuring cell volume
2
  © ISO 2022 – All rights reserved

---------------------- Page: 6 ----------------------
ISO/FDIS 22476-5:2022(E)
3.1.12
pressuremeter shear modulus
G
PBP
shear modulus obtained from the pressuremeter curve
Note 1 to entry: See 6.3
3
© ISO 2022 – All rights reserved

---------------------- Page: 7 ----------------------
ISO/FDIS 22476-5:2022(E)
Key
1 ground surface
2 borehole wall
3 pocket
4 expanding pressuremeter probe
P applied pressure
A-A axial section
B-B cross section
Figure 1 — Example of a prebored pressuremeter test
4
  © ISO 2022 – All rights reserved

---------------------- Page: 8 ----------------------
ISO/FDIS 22476-5:2022(E)
3.1.13
depth of test
distance between the ground level and the centre of the expanding length of the pressuremeter probe
measured along the borehole axis
Note 1 to entry: See Figure 2.
3.1.14
operator
qualified person who carries out the test
3.1.15
phase
section of the loading or expansion program characterized by a controlling parameter, a loading rate
and a loading direction
3.1.16
loop
sequence of the loading or expansion program including at least an unloading phase and a reloading
phase, and possibly an intermediate hold phase
3.2 Symbols and abbreviations
For the purposes of this document, the symbols in Table 1 apply.
Table 1 — Symbols
Symbol Description Unit
-1
a Corrected equipment radial displacement or volume mm.MPa
loss coefficient, taking into account calibration cylinder
or
self-deformability
3 -1
cm .MPa
-1
a Raw equipment radial displacement or volume loss coeffi- mm.MPa
r
cient
or
3 -1
cm .MPa
-1
a Radial displacement or equivalent volume loss taking into mm.MPa
cc
account calibration cylinder self-deformability
or
3 -1
cm .MPa
d Calibration cylinder inside diameter mm
cc
d Initial external diameter of the pressuremeter probe mm
c
E A Young modulus derived from a prebored pressuremeter MPa
PBP
test
G Shear modulus MPa
G First loading pressuremeter shear modulus MPa
L1
G Pressuremeter shear modulus MPa
PBP
G A reloading pressuremeter shear modulus MPa
Ri
G Apparent shear modulus of the equipment or system during MPa
sys
unloading-reloading loops
G An unloading pressuremeter shear modulus MPa
Ui
G An unloading/reloading pressuremeter shear modulus MPa
URi
k Creep parameter in reference loading programme C mm
f
L Expanding length of the pressuremeter probe mm
FD
p Corrected pressure MPa
5
© ISO 2022 – All rights reserved

---------------------- Page: 9 ----------------------
ISO/FDIS 22476-5:2022(E)
TTabablele 1 1 ((ccoonnttiinnueuedd))
Symbol Description Unit
p Constant full relief pressure for loops in reference loading MPa
1.1
programme A
p Pressure loss associated with membrane stiffness
e
p Corrected reversal pressure before loop i MPa
i
p Average corrected pressure in reference loading programme MPa
mean
D
p Minimum corrected pressure in reference loading pro- MPa
min
gramme D
p Maximum corrected pressure in reference loading pro- MPa
max
gramme D
p Pressure as read at the measuring unit MPa
r
p Seating pressure MPa
s
r Corrected radius mm
r Corrected radius at time t in reference loading programme mm
1 1
C
r Corrected radius at time t in reference loading programme mm
2 2
C
r Radius correction mm
e
r Nominal cavity radius mm
s
t Time min
T Period in reference loading programme D min
t Time 1 in reference loading programme C min
1
t Time 2 in reference loading programme C min
2
3
ΔV Corrected injected volume cm
3
ΔV Injected volume correction cm
e
3
ΔV Injected volume, as read at the control unit cm
r
3
V Total volume cm
z Test depth m
δ Corrected radial displacement mm
δ Radial displacement correction mm
e
δ Radial displacement, as read at the control unit mm
r
δ Radial displacement corresponding to the seating pressure mm
s
Δd Increase of diameter, as read at the control unit mm
r
Δd Corrected diameter increase mm
Δp Pressure increment, as read at the control unit MPa
r
Δp Corrected pressure increment MPa
ε Cavity strain -
c
ν Poisson’s ratio -
4 Equipment
4.1 General
The test with the pressuremeter is performed by the expanding of a pressuremeter membrane placed
in the ground (see Figure 1). The pressure and the associated expansion of the probe are measured and
recorded so as to obtain a pressure-expansion relationship for the ground as tested.
6
  © ISO 2022 – All rights reserved

---------------------- Page: 10 ----------------------
ISO/FDIS 22476-5:2022(E)
The equipment to carry out pressuremeter tests shall consist of the components shown in Figure 2.
The following components are mandatory:
— pressuremeter probe (no. 8 in Figure 2);
— connecting line (no. 6 in Figure 2);
— signal cable (no. 5 in Figure 2);
— displacement or volume measuring unit (no. 2 in Figure 2);
— pressure control unit (no. 3 in Figure 2);
— pressure source (no. 4 in Figure 2).
— setting rods (no.1 in Figure 2).
The following components may be added to allow orientation of the instrument if needed:
— data logger (no. 9 in Figure 2);
— sediment collection tube (no. 13 in Figure 3);
— pore pressure measuring system;
— accelerometer or geophones to perform shear wave velocity measurements.
7
© ISO 2022 – All rights reserved

---------------------- Page: 11 ----------------------
ISO/FDIS 22476-5:2022(E)
Key
1 setting rods 6 connecting line
2 displacement or volume measuring unit 7 probe rode coupling sediment collection tube
3 pressure control unit 8 pressuremeter probe
4 pressure source 9 data logger
5 signal cable z test depth
Figure 2 — Schematic diagram of pressuremeter equipment
8
  © ISO 2022 – All rights reserved

---------------------- Page: 12 ----------------------
ISO/FDIS 22476-5:2022(E)
a) Tri-cellular or monocellular b) Monocellular probe with c) Monocellular probe with
probe with expansion followed displacement measured displacement measured
through the volume of central inside the membrane at the cavity wall
cell
Key
1 control unit (CU): 1a pressurization, differential pressurization (if any) and
injection devices
 1b pressure and displacement or 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
 2c signal cable
3 depth measurement system
4 setting rods
5 pressuremeter probe 5a upper guard cell
 5b central measuring cell
 5c lower guard cell
6 ground
7 pressuremeter test pocket
8 probe body, hollow
9 probe rod coupling
10 and 11 displacement transducers
12 metal insert at the extremities
of the displacement transducers
13 membrane clamping ring
14 sediment collection tube
15 pressure transducer (if applicable)
16 compass (if applicable)
Figure 3 — Sketch of pressuremeter probes
9
© ISO 2022 – All rights reserved

---------------------- Page: 13 ----------------------
ISO/FDIS 22476-5:2022(E)
Preparation of pressuremeter test pocket shall be performed according to ISO 22476-4. The annular
space between borehole wall and the probe, if any, shall be chosen taking into account the measuring
range of the displacement transducers if any. Drilling parameters should be recorded according to
ISO 22476-15. Borehole log should be recorded according to ISO 22475-1 and ISO 14689.
4.2 Pressuremeter probe
The probe expansion shall be monitored by radial displacement [see Figure 3 b) and c)] or volume
measurement [see Figure 3 a)].
The probe shall have a cover in a shape of monocellular or be tricellular. When small strain measurement
(as defined in EN 1997-2) is needed, local displacement measurement can be implemented in the probe.
Radial displacements shall be measured by electrical transducers on two or more points, placed in the
vicinity of the mid plane [see Figure 3 b) and c)].
NOTE The arrangement shown in Figure 3 a) and b) with measurement at the inner wall of the membrane is
primarily used in soils. The arrangement shown in Figure 3 c) with measurement on inserts that penetrate the
membrane and directly bear on the cavity walls is primarily used in rocks.
In arrangement shown in Figure 3 a) and b), because membrane compression influences the readings of
pressure and displacement, proper corrections shall be determined by corresponding calibration (see
A.3).
The slenderness of the pressuremeter probe (ratio between expanding length L and initial external
FD
diameter d ) shall at least be equal to 6.
c
If included, pore pressure may be measured in the mid plane of the probe.
4.3 Connecting lines
The pressure connecting line and signal cable connect the control unit to the probe. The pressure
connecting line conveys the fluid to the probe and may be either parallel or coaxial with the signal
cable.
The injected fluid and inner diameter of the connecting lines shall be selected so that the pressure
differential between the CU and the probe remains limited.
4.4 Control unit (CU)
The control unit shall control the probe expansion and permit the reading of liquid or gas pressure and
displacement or volume as a function of time.
The pressurizing system (3 and 4 in Figure 2) shall allow:
— reaching a pressure defined by the project;
— implementing a pressure increment of 0,5 MPa as measured on the control unit in less than 20 s;
— stopping the injection when necessary.
The control unit shall include:
— equipment to apply the controlling parameters pressurize, and so to inflate or deflate 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 any;
— a device that allows, according to the type defined in Table 2, the reading and recording of the
parameters to be measured: time, pressure and displacement or volume.
10
  © ISO 2022 – All rights reserved

---------------------- Page: 14 ----------------------
ISO/FDIS 22476-5:2022(E)
Table 2 — Types of pressuremeter control unit
Type of control unit Type of test control Type of reading Type of recording
A manual manual manual
B manual automatic automatic
C automatic automatic automatic
Some means of measuring the depth of the test with appropriate accuracy shall be provided.
4.5 Measurement and control accuracy
4.5.1 Time
The accuracy of the device used to measure time shall be in accordance with Annex C.
4.5.2 Pressure and expansion
The pressure measuring devices for the liquid or for the gas in the measuring cell shall be located:
— at least in the control unit;
— if relevant, also inside the probe, in this case at less than 1 m above the centre of the measuring cell.
The maximum uncertainty of measurement of the devices measuring pressure and probe expansion
shall be as specified in Annex C.
4.5.3 Display of readings
On site, the pressure control and probe expansion measuring units shall give a simultaneous and
instantaneous display of the following readings: time, pressure of the fluid injected into the probe and
radial displacements or injected volume.
4.5.4 Expansion calibration cylinder
The main dimensions of the steel calibration cylinder serving the calibration for membrane compression
and additional effects shall be as follows:
— a known inside diameter which closely fits the deflated instrument;
— a thickness appropriate to the maximum pressure to be applied;
— a length appropriately greater than the expanding length of the instrument.
5 Test procedures
5.1 Assembly of parts
The cover, the membrane and possibly the rigid protection or the slotted tube if requ
...