types of elastomeric bearings
Post on 07-Mar-2016
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TRANSCRIPT
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1 Introduction
MK4 Elastomeric Bearings are deformable structural components constructed partially or wholly from elastomer.
They are essentially designed to transmit vertical loads and accommodate movements between a bridge and its
supporting structure simultaneously, especially for:
transmission of vertical load;
horizontal displacement in all directions;
rotation of the bearing surfaces about all axes;
accommodation of transition horizontal forces with or without additional fixings.
The bearings comprise a block of vulcanized elastomer that may be reinforced with one or more steel plates.
In addition to any internal reinforcement, bearings may have external steel load plates bonded to the upper or
lower elastomer layers or both.
MK4s Technical Department has engineers with the relevant expertise and experience to assist with the selection of
the appropriate bearing for a given application as well as providing the best solution for the clients specific problems.
Since we recognize the importance of simplicity, clarity and ease of use, we emphasize that we can offer both: the
simple standardized series of products and also highly sophisticated customized solutions for specific problems.
This brochure is intended to provide a quick and expedient reference and guide for designers, engineers and
contractors alike.
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2 Standard types
Elastomeric bearings are equipped with several vulcanized steel plates in order that internal lateral contraction will
be prevented. The result is that load carrying capacity increases, resilience is reduced, while lateral displacement
and distortion of the adjacent structural elements can be compensated by the bearing. Reinforced elastomeric
bearings are of simple construction, do not require maintenance and are corrosion proof. They have a long service
life, even under extremely onerous environmental conditions.
Bearings fully covered with ElastomerNon Anchored TypesReinforced elastomeric bearings are designed in accordance with loads to be absorbed and displacement and
distortion movements to be expected. Allowable surface contact pressures must be taken into account, as well
as the resulting bearing reaction forces, movements and installation tolerances:
Contact area Admissible Pressure Nmax Required Pressure Nmin
< 50.000 mm2 10,0 N/mm2 3,0 N/mm2
< 120.000 mm2 12,5 N/mm2 3,0 N/mm2
> 120.000 mm2 15,0 N/mm2 5,0 N/mm2 Table 1
The rubber cover is generally 2,5 mm on top and bottom surfaces and 5-6 mm laterally. The number and thickness
of layers is defined by the required translation and rotation. Therefore they are different for each bearing and are
given in page 6.
Type A: Laminated bearings fully covered with elastomer comprising only one steel reinforcing plate (former Type 1)
Type B: Laminated bearings fully covered with elastomer comprising a minimum of two steel reinforcing plates
(former Type 1)
Type A
Type B
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Bearings with outer Steel PlatesAnchored TypesWhenever the minimum surface contact pressures falls below 3 N/mm2 the following bearings should be used.
All these bearings are provided with external steel plates (see page 6).
Bearings with outer steel plates and anchorages
These bearings are especially useful where traction and high horizontal forces are to be transmitted. The anchoring
of these bearings is effected by dowels or bolts.
Type C(1): Laminated bearings with outer steel plates and bolts (former Type 2a).
Especially for use with cast-in-situ beams with occasional, temporary and irregular traction forces. These bearings
are non-replaceable.
Type C(2): Laminated bearings with outer steel plates, anchor-plates and dowels (former Type 2b).
Especially for use with steel beams with occasional, temporary and irregular traction forces. These bearings are
replaceable.
Type C(3): Laminated bearings with outer steel plates, anchor-plates and shear-keys (former Type 4).
These bearings are especially useful in case of large movements but small loads. They are replaceable.
Bearings with profiled outer steel plates
Type C(4): Laminated bearings with profiled outer steel plates (former Type 5).
These bearings can be utilized on a variety of structures. The anchoring is effected by increased friction between
substructure and bearing by the dowel-like action of the vulcanized bonded chequered or channelled plates on
the mortar bed. They are designed for both cast-in-situ concrete and precast concrete elements.
These bearings are non-replaceable.
Type C (1)
Type C (2)
Type C (3)
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Non-standard types
Low-Friction Sliding BearingsSince the deformation capacity relates to the geometrical form of the bearings, there is the facility to allow for
larger movements by adding a sliding surface in combination with a PTFE surface and stainless steel. MK4 sliding
bearings consist of a reinforced elastomeric bearing with a sliding system, including optional horizontal force
absorption. Also here the combination of all available basic types is possible.
Type D: Type B with PTFE sheet bonded to the elastomer.
Type E: Type C with one outer plate bonded to the elastomer and PTFE sheet recessed in the steel.
Plain Pad Bearings and Strip Bearings Non-reinforced elastomeric bearings also absorb displacements and distortions, but only to a limited extent due
to their reduced thickness and size, compared with reinforced elastomeric bearings. They are especially useful for
loads upto 100-150 kN.
These bearings can be produced in any desired size upto 1000 mm in length.
Type F: Plain pad bearings and strip bearings.
Guided Elastomeric Bearings Combined vertical loads and horizontal forces can be transferred with side restraints. For major horizontal forced,
as they occur in large bridge spans, it is more appropriate to use horizontal guided bearings. They transfer these
horizontal forces independently into the substructure.
Horizontal guided bearings transfer loads in both longitudinal and transverse directions.
Type G: Guided Elastomeric Bearings.
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Type D
Type E
Type G
Type F
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Type H
High Rotation BearingsIn the case of large rotations, all the above basic types can be manufactured with alternate internal steel-plates
reduced in plan size so as to offer less resistance to rotations.
The thickness of the elastomeric layers and of the steel-plates is identical to the standard bearing types.
Type H: High rotation bearings.
ILM Bearing PadsIncremental launching for bridges combines the advantage of on-site concreting with prefabricated elements.
MK4s special launching pads are for use with the incremental launching method of construction and other
techniques of sliding bridges. They can be supplied in various formats.
Type I: ILM Bearing Pads
Special BearingsMK4s Technical Department is also well equipped and willing to provide customized solutions to specific
problems. Type I
Up-lift bearing
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6345678910
2734425055596366
54698499114129144159
384960718293104115
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121136151166181196211226
617691106121136151166
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4 Bolts M16with
Dowels40x40x200
12345678910
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4 Bolts M16with
Dowels40x40x200
4812162024283236
-
0,91,8
300300x400
915202632374346505255 -
1930415263748596107118129 -
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-7990101112123134145156167178189
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4 Bolts M16with
Dowels40x40x200
24681012141618202224
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7
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0,61,3
250250x400
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4 Bolts M16with
Dowels40x40x200
35810131518202325
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200200x250200x300200x400
12345678
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4 Bolts M16with
Dowels40x40x200
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36912151821242730
4 Bolts M16with
Dowels40x40x200
0,30 150x200
C(4)
V a*b; D n W d T W d d d T
MN - mm mm mm mm mm mm mm mm rad/ 1000
A, B
Anchorages forTypes C(2), C(3)
C(1), C(2), C(3)
Total Heightexcl. anchor
plates
Total Heightincl. anchor
plates Total Height
Effectiveelastomerthickness
NON-ANCHORED TYPES ANCHORED TYPES
Admissible load Dimension No. of layers Admissible
displacement +/- Height
Effectiveelastomerthickness
Admissibledisplacement +/-
Admissble rotation
1,93,0
23313946546065697275
273442505762677074 -
4 Bolts M20with
Dowels50x50x250
617691106121136151166181196
400400x500
3456789101112
384960718293104115126 -
9121518212427303336
681012141618202224
33445566778899110121132
121136151166181196211226241256
8196111126141156171186201216
54698499114129144159174 -
350x4502,4
3501,2
mm
1 14 102 21 153 28 204 35 255 42 306 - -
0,100,15 100x100
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4 Bolts M12with
Dowels30x30x150
-
B C(4)
V a*b; D n W d T W d d d T
MN mm - mm mm mm mm mm mm mm mm rad/ 1000
Effectiveelastomerthickness
C(1), C(2), C(3)
Total Heightexcl. anchor
plates
Total Heightincl. anchor
plates Total Height
NON-ANCHORED TYPES ANCHORED TYPES
Admissible load Dimension No. of layers Admissible
displacement +/- Total Height
Effectiveelastomerthickness
Admissibledisplacement +/-
Admissble rotationAnchorages forTypes C(2), C(3)
500 550
500x600
2,93,64,5
3456789101112131415
273442505765727782868993 -
54698499114129144159174189204219 -
23313946546269758084889194
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121136151166181196211226241256271286301
617691106121136151166181196211226241
33445566778899110121132143154165
4 Bolts M20with
Dowels50x50x250
681012141618202224262830
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4,25,06,3
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4 Bolts M20with
Dowels50x50x250
600 650
600x700
3546566777869399105109113
7090110130150170190210230250270
50658095110125140155170185200
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700 750
700x800
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45607590105120135150165180195210225
4 Bolts M24with
Dowels60x60x300
681012141618202224262830
681012141618202224262830
7,58,59,6
800 850
800x800
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79102125148171194217240263286309332
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104127150173196219242265288311334357
144167190213236259282305328351374397
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547290108126144162180198216234252
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4 Bolts M24with
Dowels60x60x300
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9,512,0
900900x900
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4154677992104117128137145152158163168
79102125148171194217240263286309332355378
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547290108126144162180198216234252270288
4 Bolts M24with
Dowels60x60x300
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450450x600
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384960718293104115126137148
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Quality Control
MK4 and all their sub-suppliers are subject to a strict quality-control system as a part of the ISO 9001/EN 29002
certification.
The quality of the MK4 bearing production is continuously monitored by independent testing laboratories and
internal quality control complies with established international standards.
Quality control procedures and other verifications are applied throughout the production phase for:
materials;
workmanship;
finished product;
to ensure that the components satisfy the relevant standards.
If required, load tests on finished bearings can be performed both in-house and externally at official testing
laboratories.
Furthermore, all elastomeric bearings can be, if required, manufactured under the control of Technical University
Munich and are entitled to display TUM-sticker or under French standards (NF-sticker).
In addition, MK4 engineers are available to provide technical advice relative to quality standards of the interfaces,
bearing installation, cement joint forming, bearing plinth design, etc. .
8
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Installation
Professional installation is the unconditional prerequisite for optimum use and service life of the bearings.
Elastomeric bearings are sensitive to rough handling during construction operations. They should therefore be
treated carefully during transportation, assembly and installation.
Handling and installation of bearings should only be carried out by qualified personnel whose knowledge and
experience are well proven.
Generally bearings should be installed horizontally on an intermediate bed of mortar which serves as a levelling
course.
It must be taken into account that, due to its type of deformation, elastomeric material will not be suitable if it is
restrained laterally.
Care should be taken to keep the bearing clean and protected to avoid damage by grout or concrete and to
ensure that it can be replaced without difficulty if required. Suitable preventative measures should also be taken to
ensure that the bearings do not come into contact with grease, solvents or similar materials.
If required, MK4 can submit a technical manual which contains a detailed description of the installation process.
9
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BARCELONA
Can Pantiquet, 47- 308100 Mollet del Valls
Tel. + 34 90 215 35 33Fax + 34 93 570 60 03
mk4@mekano4.com
MADRID
Sector Esculturas, 5 Local28760 Tres Cantos
Tel. + 34 91 804 92 60Fax + 34 91 803 28 64
mk4_mdr@mekano4.com
MeKano4, S.A.
www.mekano4.com
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