NZ502460A - Energy absorbing bearing comprising end plates connected to an integral laminate - Google Patents

Abstract

The energy absorbing bearing has a primary application in the seismic isolation of structures from the ground or parts of other structures. It may also be used to dampen other forces on structures on which it is installed. The bearing consists of a pair of end plates, separated by a laminate of resilient and stiffening layers. The resilient material is preferably rubber, and the stiffening layers comprise rigid plates of plastically deformable material. The laminate is connected to the end plates at or adjacent to a central axis running from one end plate through said laminate to the other end plate. The unconnected adjacent surface portions of the laminate are capable of limited movement relative to each end plate when an external force acts on the bearing. Figure 1 illustrates an exploded view of a first embodiment. The bearing has a pair of end plates (12 and 14), of which end plate (14) would be fixed to a foundation portion of a structure being isolated. Between the end plates is a laminate comprising a stack of steel plates (18, 19, and 20) embedded in an elastomer (16). The insert (22) comprises a plastically deformable material, preferably lead. Alternatively, the bearing may have an empty core surrounded by the laminate, or no insert or hollow core, just the laminate between the end plates. In an alternative embodiment, the top end plate is not secured to the laminate, but constrained by guiding means from moving horizontally relative to the laminate, while being capable of reciprocal vertical movement relative to the laminate.