摘要 |
Unbonded fiber reinforced elastomeric isolators (FREIs) have desirable characteristics for seismic isolation, but the unbonded application also introduces several design limitations in comparison to bonded elastomeric isolators. Unbonded FREIs are not capable of resisting tensile forces, making this type of isolator inappropriate for situation where overturning is of concern or regions where large vertical accelerations are anticipated. Furthermore, since unbonded FREIs rely on friction to transfer horizontal forces, permanent slip could occur. Concerns over both transfer of tensile forces and permanent displacement can be obviated by partially bonding the FREI to the supports. In this way, partially bonded FREIs (PB-FREIs) retain the beneficial characteristics of an unbonded FREI, but also demonstrate characteristics of a bonded isolator, notably tensile forces can be transferred and potential permanent displacement is inhibited. |