Building-Use Lead Rubber Bearing, LRB

Maintains the Performance after Repeated Severe Earthquake, The Sure Durability and Reliability

Features

Wide range of supporting load (Approx. 100 – 2,000 tons/unit)
Flexible setting of vibration damping function and habitability preservation function (trigger) by the adjustment of the size of Lead Plug will provide the flexible design in accordance with the magnitude and characteristics of structure.
All in one laminated rubber and Lead Plug (damper) provides a good working performance requiring no big space for installation.
Excellent durability with maintained performance after the repeated earthquake waves.

Structure

LRB is an all in one seismic isolation device assembly of the laminated rubber to function as a load supporting and vibration isolation, and the lead plug to function as an energy absorbing function (damper).

More economical Square Type LRB(LRB-S) design is available as well.

Function of Laminated Rubber (Isolator)

(1) Load supporting function
Steel reinforced rubber will firmly support the building.High rigidity in the vertical direction as compared to the single rubber provides with the stable support of the building.
(2) Horizontal Elasticity Function (Elongated period)
Transforms the vibration of earthquake to a slow movement.Softness in the horizontal direction will calm down the severe vibration of earthquake, and elongates the period of vibration of the building.
(3) Restoring Function
Restores the building to the original position.The restoration force of the rubber will return the building to the original position after the earthquake terminated.

Function of Lead Plug (Damper)

(4) Vibration Damping Function
Damps the severe vibration of building The Lead Plug will be plastically deformed along with the deformation of laminated rubber to absorb the seismic energy, and quickly damps the vibration.
(5) Trigger Function
Depresses the vibration other than the earthquake. High rigidity of the lead plug will hold the building until the external force becomes as high as a certain level to prevent the vibration due to the storm wind etc.

Basic Characteristics

This graph shows the relation of force and displacement when the certain deformation is applied to the LRB, under the estimation of a severe earthquake.
The design model and the actual measurement show a good match, proving the stable performance of the LRB and high design precision. The restoration characteristics of the LRB is indicated in the two lines (bi-linear model), which provides a simple modeling for structural analysis. *The more precise model is available other than the LRB in the figure as well. For details please contact us.