Square-Shaped Base Isolation System, Multilayer Natural Rubber Construction with internal Lead Plug Advanced seismic isolation and economical design Advantages Support and isolation system can be provided economically, with the same performance as round LRB-S. Stability is provided in all horizontal directions and capacity for large deformations is also provided. Due to the square geometry, fire protection can be provided at low cost. A smaller bearing can be made with the same characteristics as a round LRB, saving space and reducing cost. Structure LRB-S is an isolation system which combines multilayer rubber construction with lead plugs; the former bears the load and isolates vibration, and the latter absorbs energy as a damper. Low profile and versatile. BasicFeatures This chart shows the relationship between force and displacement when LRB-S is subjected to extreme deformation as would be expected in a major earthquake. Design values concur closely with physical measurements of performance, demonstrating high accuracy of the design method. Characteristic restoring force of LRB-S is shown by two lines (bi-linear model). This characteristic makes structural modelling relatively simple. * LRB-S series can conform more precisely than the result shown in the chart. Contact OILES for more information. Function Function of multilayer rubber isolator 1) Load supporting function Rubber reinforced with steel plates provides stable support for structures. Multilayer construction provides better vertical rigidity than single layer rubber pads for supporting a building. 2) Horizontal elasticity function (prolonged oscillation period) Earthquake vibration is converted to low speed motion. As horizontal stiffness of the multi-layer rubber bearing is low, strong earthquake vibration is alleviated and the oscillation period of the building is increased. 3) Restoration function Horizontal elasticity returns the building to its original position. After an earthquake the restoring force of the rubber layers returns the building to the original position. Function of lead plug (damper) 4) Vibration damping function It absorbs large vibration of the building. As the layers of rubber are distorted, the lead plug is plastically deformed, which absorbs the earthquake energy and quickly damps the vibration. 5) Trigger function Reduces vibration from sources other than earthquake. Vibration generated by strong winds are avoided as the relative rigidity of the lead plug restricts the flexibility of the isolation system until the plug is subjected to a certain level of force.