lead rubber bearing - Antiseismic devices - Alga LRB

The Algasism LRB isolators consist of alternate layers of rubber and vulcanised reinforcement steel plates of limited thickness and a central lead core. They allow the isolation of the structure by a proper selection of the horizontal stiffness and they can dissipate energy up to 30% damping due, to the high damping capacity of the lead core. The damping value of 30% is normally the maximum damping to model the device as linear according to the international design standards.
The Algasism LRB isolators fulfil the following requirements:

Transmit the vertical loads due to permanent and accidental effects;
Capacity to support horizontal loads due to service load conditions with very low displacements
Capacity to isolate the structure by shifting the fundamental vibration period to an optimal and safe level
Capacity to dissipate energy to reduce the horizontal displacement of the isolated structure with respect to the ground

LRB isolators assure the following advantages:

- No damage to the structure that remains due to the elastic response for high intensity earthquakes with no interruption of the structural function. This is a primary goal for strategic structures (hospitals, control rooms, ecc…)
- Very well known and used in many application both for building and bridges
- Very simple maintenance mainly limited to a periodic visual inspection for all the design life
- Capacity to reduce the seismic energy from the ground to the structure with consequent simplification of the structure design