The elastomeric bearings might be incorporated in bridge structures as well as in buildings. They are commonly used in every type of the bridge - both in short-span as well as in long-span. They might be also applied in footbridges and can be used in bearing plans known as swimming support. The advantage of this kind of bearings is easy installation, resistance to atmospheric factors and anti-vibration features.
Products
Elastomeric bearings
Construction
The structure of the elastomeric bearings is layered – steel plates are vulcanized with caoutchouc. The most popular shape is rectangular in plane.
The EN 1337-3:2005 standard distinguishes 6 types of elastomeric bearings: A, B, C, D, E and F. The most commonly used types in bridge structures are type B, which has at least two reinforcing steel plates inside and type C, which has at least two reinforcing steel plates inside and two steel plates outside. To allow for movement capacity larger than ±40 mm, the sliding surface is provided and the bearing therefore is described as type D. It is allowed to combine the types in single bearing – for example B and C.
Function of elastomeric bearings
The principle of the provision of movements (horizontal and rotational) in elastomeric bearing is deformation of the elastomeric block. Each type of elastomeric bearing according to EN 1337-3:2005 might function as free movement bearings which is the feature resulting from its construction.
Combination of elastomeric bearings with restraint and guide bearings
In order to exclude the possibility of movements in one or more directions, additional restraining elements should be provided. These elements work as guides or restraints. According to EN 1337-3:2005 p. 4.2., EN 1337-8:2007 appendix B and table 1 and figure 1 in EN 1337-1:2000 such combined bearings consist of elastomeric bearing and guide or restraint bearing. Elastomeric bearing and guide bearing form guided bearing, elastomeric bearing and restraint bearing form fixed bearing.
|
|
Reactions |
Movements |
Rotations |
|||||
|---|---|---|---|---|---|---|---|---|
|
N (vertical force) |
Vx (horizontal force along axis “x”) |
Vy
(horizontal force along axis “y”) |
vx
(movement along axis “x”) |
vy
(movement along axis “y”) |
αy
(rotation around axis “x”) |
αy
(rotation around axis “y”) |
||
|
fixed (elastomeric bearing combined with restraint bearing) |
+ | + | + | - | - | + | + | |
|
guided (elastomeric bearing combined with guide bearing) |
+ | + | - | - | + | + | + | |
| + | - | + | + | - | + | + | ||
|
free movement (elastomeric bearing) |
+ | - | - | + | + | + | + | |
In case of uplifting forces the bearings must be properly designed to withstand them. However the bearings which are subjected to uplift force are not covered by the standard EN 1337-2:2005 and cannot be marked with CE. The elastomeric bearing itself cannot be designed to carry tension loads.
Technical data
|
Harmonized standard |
EN 1337-3:2005 |
|
Indended use |
in bridge structures or any other structure with comparable support conditions where requirements on individual bearings are critical |
|
Maximal designed vertical load capacity |
12 000 kN |
|
Maximal rotation capacity |
±0,034 rad |
|
Construction material |
Natural rubber (NR) |
|
Reinforcement plates |
S235 |
|
Operating temperature |
from -40 °C to 50 °C (bearings without sliding elements) from -35 °C to 48 °C (bearings with sliding elements) |
Accessories
Our elastomeric bearings combined with guide and restraint bearings are equipped with nameplates which present the basic characteristics (i.e. trade name, allowable loads both vertical and horizontal, allowable movements and rotations as well as information about place of installation and the manufacturer). Movable bearings are equipped with movements indicators.
Documents
The bearings manufactured by B2 have the Certificate of Constancy of Performance no. 0754 – CPD – 13-0149 issued by Karlsruher Institut für Technologie. According to the regulations, the bearings are CE-marked and have the Declaration of Performance issued, which are delivered to the customer at the latest with the delivery.
It is worth mentioning that for combined bearings (elastomeric bearing coupled with restraint or guide bearing) the manufacturer should present separate documents1 for these elements, because the combination of them is not a “set” according to the regulation and they do not share common essential characteristics. For more information please visit Knowledge base.
Offer B2
Our offers are tailored to the individual customer’s needs, therefore we do not follow any catalogue solutions. We focus on high quality and short production and delivery time.
We encourage to contact with us and send the inquiries by the following link: Contact.
Additional technical and legal information might be found at Knowledge base.
1 Regulation (EU) No 305/2011 of the European Parliament and of the Council of 9 March 2011 laying down harmonised conditions for the marketing of construction products and repealing Council Directive 89/106/EEC
