New Structure Technology - "Seismic Base Isolation System", proven during large-scale earth tremors
The Seismic Isolating Rubber Bearing consists of alternating laminations of thin rubber layers and steel plates (shims), bonded together to provide vertical rigidity and horizontal flexibility.
Vertical rigidity assures the isolator will support the weight of the structure, while horizontal flexibility converts destructive horizontal shaking into gentle movement.
A standard rubber block can be easily compressed and sheared because of its biaxial softness. A laminated rubber bearing can be easily sheared, but its high vertical stiffness allows it to support a heavy structure such as a building.
|Rubber block||Laminated rubber bearing (LRB)||Comparison of compressive and horizontal shear features|
Bridgestone offers several types of rubber bearing and handle a wide rage of sizes from small to large diameters.
Seismic Isolation Bearing
(Updated on Apr, 2015)
For details, please contact the local dealers in your area or Head office.
[Certifications(Minister of Land, Infrastructure and Transportation)] MVBR-0468(X0.4R)、MVBR-0430(X0.6R)
Rubber bearing that uses high damping rubber; where the rubber material itself demonstrates spring and damping capability. Generally, separate damper is not required; good for space-constraint installation.
Since its hysteresis curves are relatively smooth, seismic isolation effect can also be expected for in-building precision equipments, etc., rather than for buildings only. Rubber material has two different kinds of elastic modulus(refer red as E0.4, X0.6R), it's also applicable to light column load.
[Certifications(Minister of Land, Infrastructure and Transportation)] MVBR-0447
Rubber bearing that has a lead plug embedded at the centre of laminated natural rubber; where the"laminated natural rubber" demonstrates spring capability, while the "lead plug" demonstrates damping capability.
Generally, separate damper is not required; good for space-constraint installation. It shows hysteresis of elasto-plastic characteristics, and it is possible to fine adjust the attenuation setting by varying the lead plug diameter.
Only one kind of rubber material is used.(referred as G0.40).
[Certifications(Minister of Land, Infrastructure and Transportation)] MVBR-0295(N3.G3.G5),MVBR-0446(G4)
Rubber bearing that uses natural rubber. It has low damping performance (about 2~3% at
equivalent damping factor), excellent linearity, and stable restoring force characteristic.
Separate damper is required, but with combination of damper types, attenuation, etc., it is possible to design with greater flexibility.
Rubber material has four different kinds of elastic modulus(referred as G0.30,G0.35,G0.40, G0.45), able to support wide range of column loads.
[Certifications(Minister of Land, Infrastructure and Transportation)] MVBR-0349(SL series),MVBR-0469(SP series),MVBR-0479(SK series)
It is consist of 2 pieces: 1) a natural rubber bearing bonded with PTFE(Teflon) material and 2) a stainless steel slide plate. Small displacements are absorbed by the rubber itself, while large displacements cause the rubber bearing to slide on the plate.
Since the restoring function will be lost when the sliding occur r ed, normally it is used in combination with NRB, LRB or HDR.
There are three different type offriction coefficient, which type to be used is based on necessity of damping.