ISO 22762-3:2024

International
Standard
ISO 22762-3
Fourth edition
Elastomeric seismic-protection
2024-09
isolators —
Part 3:
Applications for buildings —
Specifications
Appareils d'appuis structuraux en élastomère pour protection
sismique —
Partie 3: Applications pour bâtiments — Spécifications
Reference number
© ISO 2024
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Published in Switzerland
ii
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 3
5 Classification . 6
5.1 General .6
5.2 Classification by construction .7
5.3 Classification by tolerance on shear properties .8
6 Requirement . 8
6.1 General .8
6.2 Type tests and routine tests .9
6.3 Functional requirements . .10
6.4 Design compressive force and design shear displacement .10
6.5 Performance requirements .10
6.5.1 General .10
6.5.2 Compressive properties .11
6.5.3 Shear properties . 12
6.5.4 Tensile properties . . 12
6.5.5 Dependences of shear properties . 13
6.5.6 Dependences of compressive properties .14
6.5.7 Shear displacement capacity . 15
6.5.8 Durability . 15
6.6 Rubber material requirements .16
6.6.1 General .16
6.6.2 Tensile properties . .16
6.6.3 Properties after ageing in air .16
6.6.4 Hardness .17
6.6.5 Ozone resistance .17
6.6.6 Other properties .17
6.7 Dimensional requirements .17
6.8 Requirements on steel used for flanges and reinforcing plates .18
6.9 Requirement on lead material for LRB .19
7 Design rules. 19
7.1 General .19
7.2 Shape factor . .19
7.2.1 First shape factor .19
7.2.2 Second shape factor . 20
7.3 Compression and shear properties . 20
7.3.1 Compressive stiffness . 20
7.3.2 Shear stiffness and equivalent damping ratio . 20
7.4 Ultimate properties .21
7.4.1 Stability at zero displacement .21
7.4.2 Stability and failure under large shear displacements . 22
7.4.3 Roll-out properties of elastomeric isolators with recessed or dowelled
connections (Type III) . 22
7.4.4 Tensile properties . . 23
7.5 Reinforcing steel plates .24
7.6 Connections .24
8 Manufacturing tolerances . .24
8.1 General .24

iii
8.2 Measuring instruments . 25
8.3 Plan dimensions . 25
8.3.1 Measurement method . 25
8.3.2 Tolerances . 25
8.4 Product height . 26
8.4.1 Measurement method . 26
8.4.2 Tolerances .27
8.5 Flatness .27
8.5.1 Measurement method .27
8.5.2 Tolerances .27
8.6 Horizontal offset .27
8.7 Plan dimensions of flanges . 28
8.8 Flange thickness . . 28
8.9 Tolerances on positions of flange bolt holes . 29
9 Marking and labelling .29
9.1 General . 29
9.2 Information to be provided . 29
9.3 Additional requirements . 30
9.4 Marking and labelling examples . 30
10 Test methods .30
11 Quality assurance .30
Annex A (normative) Tensile stress in reinforcing steel plate .31
Annex B (normative) Determination of ultimate property diagram based on experimental
results .33
Annex C (informative) Minimum recommended physical properties of rubber material .36
Annex D (informative) Effect of inner-hole diameter and second shape factor on shear
properties .37
Annex E (informative) Determination of compressive properties of elastomeric isolators .40
Annex F (informative) Determination of shear properties of elastomeric isolators.43
Annex G (informative) Method of predicting buckling limit at large deformations .48
Annex H (informative) Design of fixing bolts and flanges.55
Bibliography .58

iv
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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 45, Rubber and rubber products, Subcommittee
SC 4, Products (other than hoses).
This fourth edition cancels and replaces the third edition (ISO 22762-3:2018), of which it constitutes a minor
revision.
The changes are as follows:
— the relation of this document to ISO 22762-5 and ISO 22762-6 have been added in Introduction;
— the use of the terms "elastomeric isolators" and "seismic isolators have been made consistent throughout
the document;
— the term "fracture" has been replaced by "break" throughout the document.
— the definition of some symbols in Table 1 have been changed to make use of terms consistent;
— the information in the Table 5 has been changed to be kept consistent with Table 4;
— reference to Annex B has been added in 7.1;
— information in B.1 has been changed to be kept consistent with Table 4;
— the information in Table D.1 has been updated;
— the information in E.1 has been updated;
— the reference in Bibliography has been updated.
A list of all parts in the ISO 22762 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.

v
Introduction
The ISO 22762 series includes two parts related to specifications for elastomeric isolators, i.e. ISO 22762-2
for bridges and ISO 22762-3 for buildings. This is because the elastomeric isolator requirements for bridges
and buildings are quite different, although the basic concept of the two products is similar. Therefore,
ISO 22762-2 and the relevant clauses in ISO 22762-1 are used when ISO 22762 (all parts) is applied to the
design of bridge isolators whereas ISO 22762-3 and the relevant clauses of ISO 22762-1 are used when it is
applied to building isolators.
The main differences to be noted between elastomeric isolators for bridges and elastomeric isolators for
buildings are the following.
a) Elastomeric isolators for bridges are mainly square in shape and those for buildings are circular in shape.
b) Elastomeric isolators for bridges are designed to be used for both rotation and horizontal displacement,
while elastomeric isolators for buildings are designed for horizontal displacement only.
c) Elastomeric isolators for bridges are designed to perform on a daily basis to accommodate length
changes of bridges caused by temperature changes as well as during earthquakes, while elastomeric
isolators for buildings are designed to perform only during earthquakes.
d) Elastomeric isolators for bridges are designed to withstand dynamic loads caused by vehicles on a daily
basis as well as earthquakes, while elastomeric isolators for buildings are mainly designed to withstand
dynamic loads caused by earthquakes only.
For structures other than buildings and bridges (e.g. tanks), the structural engineer uses either ISO 22762-2
or ISO 22762-3, depending on the requirements of the structure.
ISO/TS 22762-4 is the guidance for use of ISO 22762-3. ISO 22762-5 applies to specifications and test methods
for sliding seismic-protection isolators which are not specified as elastomeric isolators. ISO 22762-6 applies
to specifications and test methods for high-durability and high-performance elastomeric isolators. Three
grades of requirements for each test item are introduced in ISO 22762-6.

vi
International Standard ISO 22762-3:2024(en)
Elastomeric seismic-protection isolators —
Part 3:
Applications for buildings — Specifications
1 Scope
This document specifies minimum requirements and test methods for elastomeric seismic elastomeric
isolators used for buildings and the rubber material used in the manufacture of such elastomeric isolators.
It is applicable to elastomeric seismic elastomeric isolators used to provide buildings with protection
from earthquake damage. The elastomeric isolators covered consist of alternate elastomeric layers and
reinforcing steel plates. They are placed between a superstructure and its substructure to provide both
flexibility for decoupling structural systems from ground motion, and damping capability to reduce
deflection at the isolation interface and the transmission of energy from the ground into the structure at the
isolation frequency.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 630 (all parts), Structural steels
ISO 22762-1:2024, Elastomeric seismic-protection isolators — Part 1: Test methods
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp/
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
breaking
rupture of elastomeric isolator (3.8) due to compression- (or tension-) shear loading
3.2
buckling
state when elastomeric isolator (3.8) lose their stability under compression-shear loading
3.3
compressive properties
K
v
compressive stiffness for all types of elastomeric isolator

3.4
cover rubber
rubber wrapped around the outside of inner rubber and reinforcing steel plates before or after curing of
elastomeric isolators for the purposes of protecting the inner rubber from deterioration due to oxygen,
ozone and other natural elements and protecting the reinforcing plates from corrosion
3.5
design compressive stress
long-term compressive force on the elastomeric isolator (3.8) imposed by the structure
3.6
effective loaded area
area sustaining vertical load in elastomeric isolator (3.8), which corresponds to the area of reinforcing steel plates
3.7
effective width
the smaller of the two side lengths of inner rubber to which direction
shear displacement is not restricted
3.8
elastomeric isolator
rubber bearing, for seismic isolation of buildings, bridges and other structures, which consists of multi-
layered vulcanized rubber sheets and reinforcing steel plates
EXAMPLE High-damping rubber bearings, linear natural rubber bearings and lead rubber bearings.
3.9
first shape factor
ratio of effectively loaded area to free deformation area of one inner rubber layer between steel plates
3.10
high-damping rubber bearing
HDR
elastomeric isolator with relatively high damping properties obtained by special compounding of the rubber
and the use of additives
3.11
inner rubber
rubber between multi-layered steel plates inside an elastomeric isolator (3.8)
3.12
lead rubber bearing
LRB
elastomeric isolator (3.8) whose inner rubber (3.11) with a lead plug or lead plugs press fitted into a hole or
holes of the elastomeric isolator body to achieve damping properties
3.13
linear natural rubber bearing
LNR
elastomeric isolator (3.8) with linear shear force-displacement characteristics and relatively low damping
properties, fabricated using natural rubber
Note 1 to entry: Any bearing with relatively low damping can be treated as an LNR bearing for the purposes of
elastomeric isolator testing.
3.14
maximum compressive stress
peak stress acting briefly on elastomeric isolator (3.8) in compressive direction during an earthquake

3.15
nominal compressive stress
long-term stress acting on elastomeric isolators (3.8) in compressive direction as recommended by the
manufacturer for the elastomeric isolator, including the safety margin
3.16
roll-out
instability of an elastomeric isolator with either dowelled or recessed connection under shear deflection
3.17
routine test
test for quality control of the production elastomeric isolators during and after manufacturing
3.18
second shape factor
ratio of the diameter of the inner rubber (3.11) to the total thickness of the
inner rubber
3.19
second shape factor
ratio of the effective width of the inner rubber (3.11) to the
total thickness of the inner rubber
3.20
shear properties
comprehensive term that covers characteristics determined from elastomeric isolator tests:
— shear stiffness, K , for LNR;
h
— shear stiffness, K , and equivalent damping ratio, h , for HDR and LRB;
h eq
— post-yield stiffness, K , and characteristic strength, Q , for LRB
d d
3.21
standard value
value of elastomeric isolator property defined by manufacturer based on the results of type test
3.22
structural engineer
engineer who is in charge of designing the structure for seismically isolated buildings and is responsible for
specifying the requirements for elastomeric isolator (3.8)
3.23
type test
test for verification either of material properties and elastomeric isolator performances during development
of the product or that project design parameters are achieved
3.24
ultimate properties
properties at either buckling, breaking, or roll-out of an elastomeric isolator under compression-shear loading
3.25
ultimate property diagram
UPD
diagram giving the interaction curve of compressive stress and buckling strain or breaking strain of an
elastomeric isolator
4 Symbols
For the purposes of this document, the symbols given in Table 1 apply.

Table 1 — Symbols and descriptions
Symbol Description
A effective plan area; plan area of elastomeric isolator, excluding cover rubber portion
A effective area of bolt
b
A overlap area between the top and bottom elastomer area of elastomeric isolator
e
A load-free area of elastomeric isolator
free
A loaded area of elastomeric isolator
load
A area of the lead plug for a lead rubber bearing
p
a side length of square elastomeric isolator, excluding cover rubber thickness, or length in longitudinal di-
rection of rectangular elastomeric isolator, excluding cover rubber thickness
a length of the shorter side of the rectangular elastomeric isolator, including cover rubber thickness
e
a′ length in longitudinal direction of the rectangular elastomeric isolator, including cover rubber thickness
B effective width for bending of flange
b length in transverse direction of the rectangular elastomeric isolator, excluding cover rubber thickness
b′ length in transverse direction of the rectangular elastomeric isolator, including cover rubber thickness
c distance from centre of bolt hole to effective flange section
D′ outer diameter of circular elastomeric isolator, including cover rubber
D diameter of flange
f
d inner diameter of reinforcing steel plate
i
d diameter of bolt hole
k
d outer diameter of reinforcing steel plate
E apparent Young's modulus of bonded rubber layer
ap
E apparent Young's modulus corrected, if necessary, by allowing for compressibility
c
s
E apparent Young’s modulus corrected for bulk compressibility depending on its shape factor (S )
c 1
E bulk modulus of rubber
∞
E Young's modulus of rubber
F tensile force on elastomeric isolator by uplift
u
G shear modulus
G (γ) equivalent linear shear modulus as a function of shear strain
eq
H height of elastomeric isolator, including mounting flange
H height of elastomeric isolator, excluding mounting flange
n
h equivalent damping ratio
eq
h (γ) equivalent damping ratio as a function of shear strain
eq
K post-yield stiffness (tangential stiffness after yielding of lead plug) of lead rubber bearing
d
K shear stiffness
h
K initial shear stiffness
i
K shear stiffness of lead plug inserted in lead rubber bearing
p
K shear stiffness of lead rubber bearing before inserting lead plug
r
K tangential shear stiffness
t
K compressive stiffness
v
L length of one side of a rectangular flange
f
M resistance to rotation
M moment acting on bolt
f
M moment acting on elastomeric isolator
r
n number of rubber layers
n number of fixing bolts
b
TTabablele 1 1 ((ccoonnttiinnueuedd))
Symbol Description
P compressive force
P design compressive force in absence of seismic action effects
P maximum compressive force including seismic action effects
max
P minimum compressive force including seismic actions effects
min
P tensile force at breaking of elastomeric isolator
Tb
Q shear force
Q shear force at breaking
b
Q shear force at buckling
buk
Q characteristic strength
d
Q shear force at roll-out
r0
S first shape factor
S second shape factor
T temperature
T standard temperature, 23 °C or 27 °C;
where specified tolerance is ±2 °C, T is standard laboratory temperature
T total rubber thickness, given by T = n × t
r r r
t thickness of one rubber layer
r
t , t thickness of rubber layer laminated on each side of plate
r1 r2
t thickness of one reinforcing steel plate
s
t thickness of outside cover rubber
U(γ) function giving ratio of characteristic strength to maximum shear force of a loop
v loading velocity
W energy dissipated per cycle
d
X shear displacement
X design shear displacement
X shear displacement at breaking
b
X shear displacement at buckling
buk
X shear displacement at roll-out
r0
X shear displacement due to quasi-static shear movement
s
X maximum shear displacement
max
X shear displacement due to dynamic shear movement
d
Y compressive displacement
Z section modulus of flange
α coefficient of linear thermal expansion
γ shear strain
γ design shear strain
γ upper limit of the total of design strains on elastomeric isolators
a
γ shear strain at breaking
b
γ local shear strain due to compressive force
c
γ shear strain due to dynamic shear movement
d
γ maximum design shear strain during earthquake
max
γ local shear strain due to rotation
r
γ shear strain due to quasi-static shear movement
s
γ ultimate shear strain
u
TTabablele 1 1 ((ccoonnttiinnueuedd))
Symbol Description
δ horizontal offset of elastomeric isolator
H
δ difference in elastomeric isolator height measured between two points at opposite extremes of the elas-
v
tomeric isolator
ε compressive strain of rubber
ε compressive creep strain
cr
ε tensile strain of elastomeric isolator
T
ε tensile-breaking strain of elastomeric isolator
Tb
ε tensile-yield strain of elastomeric isolator
Ty
ζ ratio of total height of rubber and steel layers to total rubber height
θ rotation angle of elastomeric isolator about the diameter of a circular bearing or about an axis through a
rectangular bearing
θ rotation angle of elastomeric isolator in the longitudinal direction (a)
a
θ rotation angle of elastomeric isolator in the transverse direction (b)
b
λ correction factor for calculation of stress in reinforcing steel plates
η correction factor for calculation of critical stress
κ correction factor for apparent Young's modulus according to hardness
Σγ total local shear strain
ρ safety factor for roll-out
R
ρ safety factor for tensile force
T
σ compressive stress in elastomeric isolator
σ design compressive stress
σ tensile stress in bolt
B
σ bending stress in flange
b
σ allowable bending stress in steel
bf
σ critical compressive stress in elastomeric isolator
cr
σ allowable tensile stress in steel
f
σ maximum compressive stress
max
σ minimum compressive stress
min
σ for building: nominal long-term compressive stress recommended by manufacturer
nom
σ tensile stress in reinforcing steel plate
s
σ allowable tensile stress in steel plate
sa
σ yield stress of steel for flanges and reinforcing steel plates
sy
σ tensile strength of steel for flanges and reinforcing steel plates
su
σ tensile stress
t
σ allowable tensile stress in elastomeric isolator
te
τ shear stress in bolt
B
τ allowable shear stress in steel
f
ϕ factor for computation of buckling stability
ξ factor for computation of critical stress
5 Classification
5.1 General
Elastomeric isolators are classified by construction, their ultimate properties and tolerances on their
performance.
5.2 Classification by construction
Elastomeric isolators are classified by construction, as shown in Table 2.
Other methods not listed in Table 2 may be used to fix flanges to the laminated rubber, if the resulting
construction has adequate strength to resist the shear forces and bending moments due to shear deflection.
Furthermore, such constructions shall be capable of resisting tension if the elastomeric isolator is designed
for uplift.
Table 2 — Classification by construction
Type Construction Illustration
Mounting flanges are bolted to connect-
ing flange plate, which are bonded to
the laminated rubber.
Cover rubber is added before curing of
elastomeric isolator.
Type I
Mounting flanges are bolted to connect-
ing flange plate, which are bonded to
the laminated rubber.
Cover rubber is added after curing of
elastomeric isolator.
Mounting flanges are directly bonded
Type II
to the laminated rubber.
Recess connection
Elastomeric isolators without mounting
Type III flanges, connected to base by either
recess rings or dowell pins.
Dowell connection
5.3 Classification by tolerance on shear properties
Elastomeric isolators are classified by tolerance on shear properties, as shown in Table 3.
Table 3 — Classification by tolerance of shear properties
Class Individual Global
S-A ±15 % ±10 %
S-B ±25 % ±20 %
6 Requirement
6.1 General
Elastomeric isolators for buildings and the materials used in manufacture shall meet the requirements
specified in this clause. For test items (see Table 4) that have no specific required values, the manufacturer
shall define the values and inform the purchaser prior to production.
The standard temperature for determining the properties of elastomeric isolators is 23 °C or 27 °C in
accordance with prevailing International Standards. However, it is advisable to establish a range of working
temperatures taking into consideration actual environmental temperatures and possible changes in
temperatures at the work site where the elastomeric isolators are installed.
Table 4 — Test pieces for type test
Properties Test item Test piece
Scale Minimum number
Compressive
Compressive stiffness Full-scale only 3
properties
Shear stiffness
Equivalent damping ratio
a
Shear properties Full-scale only 3
Post-yield stiffness (for LRB)
Characteristic strength (for LRB)
Tensile breaking strength
Tensile properties Scale B 3
Tensile yield strength
a
Shear strain dependence Full-scale only 3
a
Compressive stress dependence Full-scale only 3
Dependence of shear
Frequency dependence Scale A, STD, SBS 3
properties
a
Repeated loading dependence Scale B 3
Temperature dependence Scale A, STD, SBS 3
Shear strain dependence 3
Dependence of com-
Scale B
pressive properties
Compressive stress dependence 3
Scale A: Scaling such that, for a circular elastomeric isolator, diameter ≥150 mm, for a rectangular elastomeric
isolator, side length ≥100 mm and, for both types, rubber layer thickness ≥1,5 mm and thickness of reinforcing
steel plates ≥0,5 mm.
Scale B: Scaling such that, for a circular elastomeric isolator, diameter ≥500 mm, for a rectangular elastomeric
isolator, side length ≥500 mm and, for both types, rubber layer thickness ≥1,5 mm and thickness of reinforcing
steel plates ≥0,5 mm. Minimum scale factor 0,5.
STD:  Standard test piece [see ISO 22762-1:2024, Tables 10 and 11].
SBS:  Shear-block test piece specified in ISO 22762-1:2024, 5.8.3 With LRB, SBS shall only be used for ageing tests.
a
If double-shear test configuration used, 3 tests involving 3 test-pieces shall be performed. The test pieces
shall be paired such that the properties of individual test-pieces can be obtained.
b
If double-shear test configuration used, 2 tests shall be performed.

TTabablele 4 4 ((ccoonnttiinnueuedd))
Properties Test item Test piece
Scale Minimum number
b
Ultimate properties Shear displacement capacity Scale B 3
Ageing Scale A, STD, SBS 2
Durability
Creep Scale A 2
Scale A: Scaling such that, for a circular elastomeric isolator, diameter ≥150 mm, for a rectangular elastomeric
isolator, side length ≥100 mm and, for both types, rubber layer thickness ≥1,5 mm and thickness of reinforcing
steel plates ≥0,5 mm.
Scale B: Scaling such that, for a circular elastomeric isolator, diameter ≥500 mm, for a rectangular elastomeric
isolator, side length ≥500 mm and, for both types, rubber layer thickness ≥1,5 mm and thickness of reinforcing
steel plates ≥0,5 mm. Minimum scale factor 0,5.
STD:  Standard test piece [see ISO 22762-1:2024, Tables 10 and 11].
SBS:  Shear-block test piece specified in ISO 22762-1:2024, 5.8.3 With LRB, SBS shall only be used for ageing tests.
a
If double-shear test configuration used, 3 tests involving 3 test-pieces shall be performed. The test pieces
shall be paired such that the properties of individual test-pieces can be obtained.
b
If double-shear test configuration used, 2 tests shall be performed.
Some of these properties may be determined using one of the standard test pieces detailed in
ISO 22762-1:2024, Tables 10 and 11. The standard test pieces are used for non-specific product tests, such as
testing in the development of new materials and products.
6.2 Type tests and routine tests
6.2.1 Testing to be carried out on elastomeric isolators is classified into “type tests” and “routine tests”.
6.2.2 Type tests shall be conducted either to ensure that project design parameters have been achieved (in
which case the test results shall be submitted to the structural engineer for review prior to production) or
to verify elastomeric isolator performance and material properties during development of the product. The
test piece for each type test shall be full-scale or one of the options specified in Table 4. The test piece shall
not have been subjected to any previous test programme. The tests shall be performed on test pieces not
subjected to any scragging, unless the production elastomeric isolators are to be supplied after scragging. In
that case, the test pieces shall be subjected to the same scragging procedure as the production elastomeric
isolators.
6.2.3 Previous type test results may be substituted, provided the following conditions are met.
a) Elastomeric isolators are fabricated in a similar manner and from the same compound and adhesive.
b) All corresponding external and internal dimensions are within 10 % of each other. Flange plates are
excluded.
c) First and second shape factors are equal to or larger than those in previous tests.
d) The test conditions, such as maximum and minimum vertical load applied in the ultimate property test
(see 6.5.7), are more severe.
Routine tests are carried out during production for quality control. Sampling is allowed for routine testing
for projects with agreement between structural engineer and manufacturer. Sampling shall be conducted
randomly and cover not less than 20 % of the production of any elastomeric isolator design. For a given
project, tests shall cover not less than four test pieces for each size and not less than 20 test pieces in total.
If elastomeric isolators are supplied after scragging, the routine test shall be performed on scragged
elastomeric isolators.
6.3 Functional requirements
Elastomeric isolators for buildings are designed and manufactured to have the performance characteristics
required so that they deform in all directions with the proper stiffness (with damping, if required) during
an earthquake.
In the application of elastomeric isolators, attention shall be paid to the following points.
a) The elastomeric isolators shall be installed horizontally between the structure and foundation.
b) Once installed, the elastomeric isolators shall not be subjected to a constant shear force.
c) When elastomeric isolators are to be installed under relatively flexible columns, the rotation at the top
of the elastomeric isolator caused by be
...