Lead Rubber Bearing (LRB)

LRB lead rubber bearing is a seismic isolator, which can reduce and limit the energy transferred from the ground to the upper structures during earthquakes. This bearing includes a lead plug embedded at the center of a laminated natural rubber structure, where the rubber incorporates the spring capability and the lead plug provides the damping capability and dissipates the energy. Thanks to the lead core these devices have a higher initial stiffness and rigid-plastic behaviour, and thus allow very small movement due to loads including wind and braking.

Generally, a separate damper is not required making it a good choice for cases of space constraints. Its hysteresis resembles elasto-plastic materials. The attenuation can be tuned by varying the lead plug diameter.

Due to its simplicity and economy, LRB bearings are widely applied in numerous kinds of bridges, sky-scraping buildings and steel structural constructions, especially in earthquake-prone areas. LRB bearings can work as laminated rubber bearing in normal conditions and as seismic isolator during earthquakes.

After an earthquake, the bearings will restore to its initial position due to the self-recovery characteristics of the rubber and lead.