EN ISO 22476-4:2012

SLOVENSKI STANDARD
01-junij-2013
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Geotechnical investigation and testing - Field testing - Part 4: Ménard pressuremeter test
(ISO 22476-4:2012)
Geotechnische Erkundung und Untersuchung - Felduntersuchungen - Teil 4:
Pressiometerversuch nach Ménard (ISO 22476-4:2012)
Reconnaissance et essais géotechniques - Essais en place - Partie 4: Essai au
pressiomètre Ménard (ISO 22476-4:2012)
Ta slovenski standard je istoveten z: EN ISO 22476-4:2012
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.

EUROPEAN STANDARD
EN ISO 22476-4
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2012
ICS 93.020
English Version
Geotechnical investigation and testing - Field testing - Part 4:
Ménard pressuremeter test (ISO 22476-4:2012)
Reconnaissance et essais géotechniques - Essais en place Geotechnische Erkundung und Untersuchung -
- Partie 4: Essai au pressiomètre Ménard (ISO 22476- Felduntersuchungen - Teil 4: Pressiometerversuch nach
4:2012) Ménard (ISO 22476-4:2012)
This European Standard was approved by CEN on 30 November 2012.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same
status as the official versions.

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

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2012 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 22476-4:2012: E
worldwide for CEN national Members.

Contents Page
Foreword .3
Foreword
This document (EN ISO 22476-4:2012) has been prepared by Technical Committee CEN/TC 341
“Geotechnical Investigation and Testing”, the secretariat of which is held by ELOT, in collaboration with
Technical Committee ISO/TC 182 "Geotechnics".
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 June 2013, and conflicting national standards shall be withdrawn at
the latest by June 2013.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
INTERNATIONAL ISO
STANDARD 22476-4
First edition
2012-12-01
Geotechnical investigation and testing —
Field testing —
Part 4:
Ménard pressuremeter test
Reconnaissance et essais géotechniques — Essais en place —
Partie 4: Essai au pressiomètre de Ménard
Reference number
ISO 22476-4:2012(E)
©
ISO 2012
ISO 22476-4:2012(E)
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO’s
member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2012 – All rights reserved

ISO 22476-4:2012(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 2
3 Terms, definitions and symbols . 2
3.1 Terms and definitions . 2
3.2 Symbols . 4
4 Equipment . 6
4.1 General description . 6
4.2 Pressuremeter probe . 7
4.3 Pressure and volume control unit (CU) . 11
4.4 Connecting lines . 11
4.5 Injected liquid . 11
4.6 Measurement and control . 11
4.7 Data logger .12
5 Test procedure .12
5.1 Assembling the parts .12
5.2 Calibration and corrections .12
5.3 Pressuremeter pocket and probe placing .12
5.4 Preparation for testing .13
5.5 Establishing the loading programme .13
5.6 Establishing the differential pressure .14
5.7 Expansion .15
5.8 Back-filling of the pockets .15
5.9 Safety requirements .15
6 Test results .16
6.1 Data sheet and field print-out .16
6.2 Corrected pressuremeter curve .17
6.3 Calculated results .17
7 Reporting .18
7.1 General .18
7.2 Field report .18
7.3 Test report .18
Annex A (normative) Geometrical features of pressuremeter probes .20
Annex B (normative) Calibration and corrections .23
Annex C (normative) Placing the pressuremeter probe in the ground .31
Annex D (normative) Obtaining pressuremeter parameters .38
Annex E (normative) Resolution and uncertainties .46
Annex F (normative) Pressuremeter test records .47
Bibliography .51
ISO 22476-4:2012(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 22476-4 was prepared by the European Committee for Standardization (CEN) Technical Committee
CEN/TC 341, Geotechnical investigation and testing, in collaboration with Technical Committee ISO/TC 182,
Geotechnics, Subcommittee SC 1, Geotechnical testing, in accordance with the Agreement on technical
cooperation between ISO and CEN (Vienna Agreement).
ISO 22476 consists of the following parts, under the general title Geotechnical investigation and testing —
Field testing:
— Part 1: Electrical cone and piezocone penetration test
— Part 2: Dynamic probing
— Part 3: Standard penetration test
— Part 4: Ménard pressuremeter test
— Part 5: Flexible dilatometer test
— Part 7: Borehole jack test
— Part 9: Field vane test
— Part 10: Weight sounding test [Technical Specification]
— Part 11: Flat dilatometer test [Technical Specification]
— Part 12: Mechanical cone penetration test (CPTM)
iv © ISO 2012 – All rights reserved

INTERNATIONAL STANDARD ISO 22476-4:2012(E)
Geotechnical investigation and testing — Field testing —
Part 4:
Ménard pressuremeter test
1 Scope
This part of ISO 22476 specifies the equipment requirements, execution of and reporting on the Ménard
pressuremeter test.
NOTE 1 This part of ISO 22476 fulfils the requirements for the Ménard pressurermeter test, as part of the geotechnical
investigation and testing according to EN 1997-1 and EN 1997-2.
This part of ISO 22476 describes the procedure for conducting a Ménard pressuremeter test in natural soils,
treated or untreated fills and in weak rocks, either on land or off-shore.
The pressuremeter test results of this part of ISO 22476 are suited to a quantitative determination of ground
strength and deformation parameters. They may yield lithological information. 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-
2:2007, 2.4.1.4(2) P, 4.1 (1) P and 4.2.3(2) P).
The Ménard pressuremeter test is performed by the radial expansion of a tricell probe placed in the ground
(see Figure 1). During the injection of the liquid volume in the probe, the inflation of the three cells first brings
the outer cover of the probe into contact with the pocket wall and then presses on them resulting in a soil
displacement. Pressure applied to and the associated volume expansion of the probe are measured and
recorded so as to obtain the stress-strain relationship of the soil as tested.
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 14689-1 obtained during the pressuremeter test
operations, the test results of this part of ISO 22476 are suited to the quantitative determination of a ground
profile, including
— the Ménard E
modulus,
M
— the Ménard limit pressure p and
LM
— the Ménard creep pressure p .
fM
This part of ISO 22476 refers to a probe historically described as the 60 mm G type probe. This part of
ISO 22476 applies to test depths limited to 50 m and test pressure limited to 5 MPa.
NOTE 2 Ménard pressuremeter tests are carried out with other probe diameters and pocket dimensions such as shown
below.
Probe Drilling diameter (mm)
Designation Diameter (mm) min max
AX 44 46 52
BX 58 60 66
NX 70/74 74 80
Two alternative methods of measurement are provided as follows.
— Procedure A: data are recorded manually.
— Procedure B: data are recorded automatically.
ISO 22476-4:2012(E)
2 Normative references
The following referenced documents are indispensable for the application 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 14689-1, Geotechnical investigation and testing — Identification and classification of rock — Part 1:
Identification and description
ISO 22475-1, Geotechnical investigation and testing — Sampling methods and groundwater measurements —
Part 1: Technical principles for execution
ENV 13005:1999, Guide to the expression of uncertainty in measurement
3 Terms, definitions and symbols
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1.1
pressuremeter
whole equipment which is used to carry out a Ménard pressuremeter test, excluding the means necessary to
place the pressuremeter probe into the ground
NOTE 1 A pressuremeter includes a pressuremeter probe, a pressure and volume control unit, called CU, lines to
connect the probe to the CU and, in the case of procedure B, a data logger which is either built into the CU or linked to it.
NOTE 2 See Figure 2.
3.1.2
pressuremeter test pocket
circular cylindrical cavity formed in the ground to receive a pressuremeter probe
3.1.3
pressuremeter borehole
borehole in which pressuremeter pockets with circular cross sections are made in the ground, and into which
the pressuremeter probe is to be placed
3.1.4
pressuremeter test
process during which a pressuremeter probe is inflated in the ground and the resulting pocket expansion is
measured by volume as a function of time and pressure increments according to a defined programme
NOTE See Figure 4 and F.1.
3.1.5
pressuremeter sounding
whole series of sequential operations necessary to perform Ménard pressuremeter testing at a given location,
i.e. forming pressuremeter test pockets and performing pressuremeter tests in them
NOTE See F.2.
3.1.6
pressuremeter pressure reading, p
r
pressure p as read at the CU elevation in the liquid circuit supplying the central measuring cell
r
2 © ISO 2012 – All rights reserved

ISO 22476-4:2012(E)
3.1.7
pressure loss
difference between the pressure inside the probe and the pressure applied to the pocket wall
3.1.8
volume loss
difference between the volume actually injected into the probe and the volume read on the measuring device
3.1.9
raw pressuremeter curve
graphical plot of the injected volumes recorded at time 60 s, V , versus the applied pressure at each
pressure hold, p
r
3.1.10
corrected pressuremeter curve
graphical plot of the corrected volume V versus the corrected pressure p
NOTE See Figure 5.
3.1.11
Ménard creep
difference in volumes recorded at 60 s and at 30 s at each pressure hold: V − V = ΔV
60 30 60/30
3.1.12
corrected Ménard creep curve
graphical plot of the corrected Ménard creep versus the corrected applied pressure at each pressure hold
NOTE See Figure 5.
3.1.13
pressuremeter log
graphical report of the results of the pressuremeter tests performed in pockets at a succession of depths in the
same pressuremeter borehole, together with all the information gathered during the drilling
NOTE See Annex F.
3.1.14
Ménard pressuremeter modulus, E
M
E-modulus obtained from the section between (p V ) and (p V ) of the pressuremeter curve
1, 1 2, 2
NOTE See Figure 5 and Annex D.
3.1.15
Ménard pressuremeter limit pressure, p
LM
pressure at which the volume of the test pocket at the depth of the measuring cell has doubled its original volume
NOTE See Annex D.
3.1.16
pressuremeter creep pressure, p
fM
pressure derived from the creep curve
NOTE See Annex D.
3.1.17
operator
qualified person who carries out the test
3.1.18
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
ISO 22476-4:2012(E)
3.2 Symbols
For the purposes of this document, the symbols given in Table 1 apply.
Table 1 — Symbols
Symbol Description Unit
a Apparatus volume loss coefficient cm /MPa
d Outside diameter of the inner part of the probe with slotted tube mm
ci
d Inside diameter of the calibration cylinder used for the volume loss calibration mm
i
Outside diameter of the central measuring cell, including any additional protection such as a
d mm
c
slotted tube
d Drilling tool diameter mm
t
e Wall thickness of the calibration cylinder used for the volume loss calibration mm
l Length of the calibration cylinder used for the volume loss calibration mm
p
l Length of each guard cell mm
g
l Length of each guard cell for a short central measuring cell pressuremeter probe mm
gs
l Length of each guard cell for a long central measuring cell pressuremeter probe mm
gl
l Length along the tube axis of the slotted section of the slotted tube mm
m
l Length of the central measuring cell of the probe, measured after fitting the membrane mm
c
l Length of the short central measuring cell after fitting the membrane mm
cs
l Length of the long central measuring cell after fitting the membrane mm
cl
m Minimum value, strictly positive, of the m slopes cm /MPa
E i
Slope of the corrected pressuremeter curve between the two points with coordinates (p ,
i-1
m cm /MPa
i
V ) and (p , V ).
i-1 i i
p Pressure applied by the probe to the ground after correction MPa
p Correction for membrane stiffness usually called pressure loss of the probe MPa
e
p Pressure at the origin of the segment exhibiting the slope m MPa
E E
p Ultimate pressure loss of the probe MPa
el
p Pressuremeter creep pressure MPa
fM
Gas pressure applied by the control unit indicator to the guard cells of the pressuremeter
p MPa
g
probe
Hydrostatic pressure between the control unit indicator and the central measuring cell of the
p MPa
h
pressuremeter probe
p Gas pressure in the guard cells MPa
k
p Ménard pressuremeter limit pressure of the ground MPa
LM
p * Ménard net pressuremeter limit pressure of the ground MPa
LM
p Ménard pressuremeter limit pressure as extrapolated by the hyperbolic best fit method MPa
LMH
p Ménard pressuremeter limit pressure as extrapolated by the double hyperbolic method MPa
LMDH
p Ménard pressuremeter limit pressure as extrapolated by the reciprocal curve method MPa
LMR
p Pressure loss of the central measuring cell membrane for a specific expansion MPa
m
p Pressure reading at the CU transducer elevation in the central measuring cell liquid circuit MPa
r
p Liquid pressure in the central measuring cell of the pressuremeter probe MPa
c
p Target pressure for each pressure hold according to loading programme MPa
t
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 required for incrementing to the next pressure hold s
i
t Time the loading pressure level is held s
h
4 © ISO 2012 – All rights reserved

ISO 22476-4:2012(E)
Table 1 (continued)
Symbol Description Unit
u Pore water pressure in the ground at the depth of the test MPa
s
z Elevation, positively counted above datum m
z Elevation of the pressure measuring device for the liquid injected in the measuring cell m
c
Elevation of the pressure measuring device for the gas injected in the guard cells of the
z m
cg
pressuremeter 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
z Elevation of the ground water table (or free water surface in a marine or river environment) m
w
CU Pressure and volume control unit —
Type of pressuremeter probe where the three cells are formed by three separate
E —
membranes in line
E Ménard pressuremeter modulus MPa
M
Type of pressuremeter probe where the central measuring cell is formed by a dedicated
G —
membrane over which an external membrane is fitted to form the guard cells (see Figure 2)
K Coefficient of earth pressure at rest at the test depth —
o
Value, after zeroing and data correction, of the volume injected in the central measuring cell
V cm
and measured 60 s after starting a pressure hold
V Original volume of the central measuring cell, including the slotted tube, if applicable cm
c
V The average corrected volume between V and V cm
m 1 2
V Volume obtained in the volume loss calibration test (see Figure B.2) cm
p
Value, after data correction, of the volume injected in the central measuring cell for pressure
V cm
E
p
E
Value, after data correction, of the volume injected in the central measuring cell when the
V cm
L
original volume of the pressuremeter cavity has doubled
V Volume injected in the probe as read on the CU, before data correction cm
r
V Volume of the central measuring cell possibly including the slotted tube cm
t
V Corrected volume at the origin of the pressuremeter modulus pressure range (see Figure 5) 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 the
V cm
pressure hold
Volume injected in the central measuring cell as read 60 s after the beginning of the
V cm
pressure hold
β Coefficient used to determine the pressuremeter modulus pressure range —
γ
Unit weight of soil 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
−1
λ Rate of change of pressure head of gas at p per metre depth m
g k
ν Poisson’s ratio —
σ Total vertical stress in the ground at test depth kPa
vs
σ Total horizontal stress in the ground at test elevation kPa
hs
Δp Loading pressure increment MPa
Δp Initial pressure increment MPa
Injected volume change from 30 s to 60 s after reaching the pressure hold − the Ménard
ΔV cm
60/30
creep
ΔV 60 s injected volume change between successive pressure holds cm
60/60
ISO 22476-4:2012(E)
4 Equipment
4.1 General description
The principle of the Ménard pressuremeter test is shown in Figure 1.
Key
1 ground surface
2 ground
3 pocket
4 expanding pressuremeter probe
p applied pressure
A–A axial section
B–B cross section
Figure 1 — Principle of a Ménard pressuremeter test
6 © ISO 2012 – All rights reserved

ISO 22476-4:2012(E)
The pressuremeter as shown schematically in Figure 2 shall include:
— tri-cell probe;
— string of rods to handle the probe;
— control unit (CU);
— lines connecting the control unit to the probe.
The control unit (CU) 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;
— device which permits the direct reading and, in the case of procedure B, the automatic recording of the
parameters to be measured: time, pressure and volume.
The pressure measuring devices for the liquid in the central measuring cell and for the gas in the guard cells
shall be located either
— above the ground surface, or
— inside the probe, less than 1 m above the centre of the central measuring cell.
In the first case, the CU shall be provided with means to check the stabilized pressure value at the probe.
Some means of measuring the depth of the test with appropriate accuracy shall be provided.
4.2 Pressuremeter probe
Two types of probe shall be used according to ground type and condition:
— probe with a flexible cover;
— probe with a flexible cover and either an additional more rigid protection or a slotted steel tube.
These probes are described in Figure 3 a) and Figure 3 b), respectively, and their geometrical features are
given in Table A.1.
When the probe is driven or pushed into the ground (see C.3), it shall be fitted with the more rigid protection or
a slotted tube together with a extension tube completed by either a point or a cutting shoe.
NOTE If no slotted tube is involved, the probe body must be designed to withstand driving or pushing.
3 3
The probe shall be capable of a volumetric expansion of at least 700 cm (550 cm for a probe with a short
central measuring cell within a slotted tube).
ISO 22476-4:2012(E)
Key
1 control unit (CU): 5 pressuremeter probe:
1a pressurization, differential pressurization and injection devices 5a upper guard cell
1b pressure and volume measuring devices 5b central measuring cell
1c acquisition, storage and printing out of the data (required for procedure B) 5c lower guard cell
2 connecting lines: 6 ground
2a line for liquid injection 7 pressuremeter test pocket
2b line for gas injection 8 probe body, hollow
3 depth measurement system 9 probe rod coupling
4 rods
Figure 2 — Diagram of a Ménard pressuremeter
8 © ISO 2012 – All rights reserved

ISO 22476-4:2012(E)
4.2.1 Probe with flexible cover
The probe shall be made up of three cylindrical cells of circular cross-section along the same axis (see
Figure A.1). During a test these cells shall expand simultaneously against the pocket wall. The probe includes:
— one central measuring cell, with an outside diameter d and a length l (l for a “long probe” or l for short
c c cl cs
probe – see Table A.1), which shall expand radially in a pocket and shall apply a uniform stress to the
pocket wall. This cell shall be inflated by injecting a liquid which is assumed to be incompressible;
— two guard cells with an outside diameter d and a length l (l or l ) located above and below the central
g g gl gs
measuring cell. These cells shall be designed to apply to the pocket wall a stress close to, but not greater
than, the stress induced by the central measuring cell. These cells shall be inflated by gas pressure.
The probe shall consist of a hollow steel core with passages to inject the proper fluids to inflate the cells. The
probe shall be fitted with a central measuring cell membrane and a flexible cover sleeve. The steel core, on
its outside curved surface, shall usually bear a network of grooves which uniformly distribute the liquid in the
central measuring cell under the membrane. To this core shall be fixed the membrane and the flexible cover.
The top of the core shall be threaded and coupled to the string of rods handling the probe from ground level;
the central measuring cell membrane shall isolate the fluid in the central measuring cell from the gas of the
guard cells. The flexible cover which overlies the central measuring cell membrane shall give form to the guard
cells. A flexible protection made of thin steel strips usually 17 mm wide either overlapping (up to half-way) or
isolated, running between fixing rings (see Figure A.1) may be added over the cover. Fluid lines shall connect
the probe cells to the pressure and volume control unit (CU). The drain tap of the measuring cell shall protrude
from the bottom of the steel core.
NOTE The flexible protection may be added to reduce damage to the cover from sharp fragments protruding from
the pocket wall.
4.2.2 Probe with slotted tube
This probe shall consist of two parts:
— an inner part which shall be an assembly of three cylindrical cells of circular cross-section along the
same axis; and
— an outer part which shall be made of a slotted steel tube (see Figure A.1). 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 inner part includes:
— one central measuring cell, with an outside diameter d and a length l (l for a “long probe” or l for short
c c cl cs
probe – see Table A.1), which shall expand radially in the slotted tube and shall apply a uniform stress to
the tube wall. This cell shall be inflated by injecting a liquid which is assumed to be incompressible;
— two guard cells with an outside diameter d and a length l (l or l ), located above and below the central
g g gl gs
measuring cell. These cells shall be designed to apply to the slotted tube wall a stress close to, but not
greater than, the stress induced by the central measuring cell. These cells shall be inflated by gas pressure.
During a test these cells shall act simultaneously on the inside wall of the slotted tube, which shall transfer the
stresses to the pocket wall.
The outside steel tube shall carry at least six axial or helical slots evenly distributed round the circumference
(Figure 3 b).The tube slotted length l is measured along the tube axis. This length shall be the greater of:
m
1,3 (l + 2 l ) or 800 mm
c g
Before and after expansion, the opening of each slot of the tube shall be less than or equal to 0,4 mm. After
expansion the slotted tube and the slots shall be able to recover their original shape and size.
The assembly within the slotted tube shall be located by flexible spacers so as to allow the probe to expand
radially with a minimum of resistance.
ISO 22476-4:2012(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
Dimensions are given in Annex A.
Figure 3 — Pressuremeter probe (diagrammatic)
10 © ISO 2012 – All rights reserved

ISO 22476-4:2012(E)
4.3 Pressure and volume control unit (CU)
The control unit (CU) shall be built around a cylindrical volumeter fitted with a pressurizing device and a set
of measuring devices. The CU shall control the probe cell expansion and permit the simultaneous reading of
liquid and gas pressures and injected liquid volume as a function of time.
The pressurizing device shall allow:
— reaching the pressuremeter limit pressure or a pressure p at least equal to 5 MPa;
r
— 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 CU;
— controlling the pressure difference between the measuring cell and the guard cells;
— injecting a volume of liquid in the measuring cell larger than 700 cm .
Further, in the control unit a valve between the volumeter and the pressure measuring device shall allow
stopping the injection.
4.4 Connecting lines
The flexible lines shall connect the pressure and volume control unit (CU) 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.
4.5 Injected liquid
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.
4.6 Measurement and control
4.6.1 Time
The accuracy of the device used to measure time shall be in accordance with Annex E.
4.6.2 Pressure and volume
The resolution of measurement of the devices measuring pressure and volume shall be in accordance with Annex E.
4.6.3 Display of readings
At the site the pressure and volume control unit (CU) shall give a simultaneous and instantaneous display of
the following readings: time, pressure of the liquid injected into the measuring cell, volume of the liquid injected
and pressure of the gas in the guard cell circuit.
4.6.4 Volume loss calibration cylinder
The main features of this steel cylinder (Figure B.1) shall be as follows:
— measured inside diameter d not more than 66 mm;
i
— wall thickness e not less than 8 mm;
— length l more than 1 m or the slot length l , whichever is greater.
p m
ISO 22476-4:2012(E)
4.7 Data logger
The data logger, the device to acquire and record the data under procedure B, shall be fitted with
— an internal clock,
— a printer, and
— a memory device readable by a computer.
The data logger shall be designed to record the raw data from the transducers, the zeros, calibration coefficients
and identification of each and the resulting calibrated data of pressure and volume.
The data logger shall not interfere with the conduct of a test as specified in 5.7 and it shall not obscure any
other measuring devices. It shall be designed so as to automatically:
— record its own identification parameters: date, hour, minute, second, CU number, data logger number,
memory device number;
— require the input of the information necessary to identify the test, as described in 5.4;
— prevent the input of pressure and volume data or other information not obtained during the testing process.
The data logger shall include an alarm device or a special display for the following events:
— no memory device in place;
— no test identification parameters recorded according to 5.4;
— no electric power.
5 Test procedure
5.1 Assembling the parts
The cover, the membrane and possibly the slotted tube if required shall be selected according to the expected
stress-strain parameters of the ground in which the probe is to be used. They shall each fulfil the specifications
given in Annex A. Then the probe shall be linked to the control unit through the connecting lines.
The whole system shall be filled with liquid and purged to remove air bubbles.
5.2 Calibration and corrections
Calibration and correction shall be performed according to Annex B. Copies of the calibration results shall be
available at the testing location.
5.3 Pressuremeter pocket and probe placing
In pressuremeter testing, it is paramount to achieve a high quality pocket wall. The procedures and requirements
in Annex C shall be followed.
The preparation of satisfactory pockets shall be the most important step in obtaining acceptable pressuremeter
test results.
Three conditions shall be fulfilled to obtain a satisfactory test pocket:
— the equipment and method used to prepare the test pocket shall cause the least possible disturbance to
the soil at the cavity wall (see C.1);
— the diameter of the cutting tool shall meet the specified tolerances (see C.2.2);
12 © ISO 2012 – All rights reserved

ISO 22476-4:2012(E)
— the pressuremeter test shall be performed immediately after the pocket is formed (see Table C.1 and
C.1.2 and C.1.3)
NOTE An indication of the quality of the test pocket is given by the shape of the pressuremeter curve and the
magnitude of scatter of the test readings (see D.2).
5.4 Preparation for testing
The pressure and volume control unit (CU) and the data logger shall be protected from direct sunlight.
The position of the pressuremeter sounding shall be marked on a drawing and identified by its location details.
If the sounding is inclined, its slope and direction shall be recorded (see Annex F).
As next step, for each sounding:
— the acquisition and recording device, i.e. the data logger, shall be initialized (procedure B);
— the initial reading of each transducer shall be checked and, if appropriate, recorded (procedures A and B).
The identification parameters of the test shall be recorded, either in the memory device or on the data sheet
with a carbon copy (see Annex F):
— test operator identification;
— file number;
— sounding number;
— type of probe;
— technique of pocket drilling (see Annex C);
— ground identification and description according to ISO 14688-1 and ISO 14689-1;
— method of probe setting;
— calibrations test references (see Annex B);
— elevation z of the pressure transducer or value of z − z for this transducer (see Figure D.1);
c c N
— elevation z of the test location or depth (z − z ) of the probe (see Figure D.1);
s N s
— differential pressure setting (see B.4.4).
5.5 Establishing the loading programme
The loading programme of a pressuremeter test shall be the relationship between time and pressure as applied
by the probe to the ground (Figure 4).
At each pressure hold the pressure shall be held constant in the central measuring cell and in the guard cells
for a time t of 60 s. In procedure A, if a variation in p during a pressure hold exceeds the greater of 25 kPa or
h r
0,5 % of the current pressure value p , the final value of pressure shall be recorded.
r
The initial pressure increment Δp to be used shall be decided by the operator after observation of the drilling
parameters, examination of the core or the drill cuttings and by instruction. Once the initial readings have
been recorded, the operator shall observe the creep parameter ΔV and the differences ΔV between
60/30 60/60
successive 60 s volume readings and as a result may change the pressure increment so as to:
— obtain approximately 10 points during the test and
— reach the end of the test (see 5.7.2).
ISO 22476-4:2012(E)
Key
p target pressures
t
Δp pressure increment
p pressure hold during th
r
C loading phase
t time
t pressure increment time
i
t duration of a pressure hold
h
D unloading phase
Figure 4 — Loading programme for a Ménard pressuremeter test
The time t for raising the pressure by the next step Δp shall be less than 20 s when the line length is less than
i
50 m. Appropriate adjustment to t shall be made for the case of the line length exceeding 50 m (when in coil).
i
Once the test is completed as described in 5.7.2, unloading shall be performed steadily and without stopping.
5.6 Establishing the differential pressure
The pressure of the gas in the guard cells shall be lower than the pressure in the central measuring cell by at
least twice the central measuring cell membrane pressure loss p as defined in B.2.
m
At the elevation of the control unit (CU), the pressure difference which is necessary to keep the above-mentioned
equilibrium is called the differential pressure. It shall be calculated according to B.4.4. This differential pressure
shall be set before the start of the test and checked at each pressure hold.
At the jobsite, before carrying out the tests, the operator shall be given a table exhibiting differential pressures
as a function of the depth according to the type of probes used.
14 © ISO 2012 – All rights reserved

ISO 22476-4:2012(E)
5.7 Expansion
The expansion process shall include:
— applying a uniform pressure to the pocket wall through the pressuremeter probe according to th
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