A State of Art on Effectiveness of Isolation System

This paper investigate the effectiveness of isolation system under seismic response. Base isolation reduce the response of short building under seismic condition, but for tall building or mid-rise building base isolation doesn't prove to be more effective. In base-isolated (BI) buildings, although the relative displacement with in the superstructure is usually small, the displacement across the base isolation system can be relatively large. The base displacement is therefore of main concern in the seismic code provisions for base-isolated buildings. Because of the large displacement demand on the isolation system, the necessary flexibility of base isolation is usually provided at the foundation level in a low- to medium-rise building. In addition, the effectiveness of base isolation reduces as the superstructure becomes more flexible and therefore the application of the base isolation technique is limited, in practice, to buildings in the low- to medium-rise range. In order to alleviate the above problem, Pan et al. proposed a new isolation concept in which the superstructure of a base-isolated building is divided into several segments. The individual segments, which may comprise a few stories are interconnected by additional vibration isolation systems. Segmental building has also possesses the ability to decoupled the building from the harmful horizontal earthquake ground motions. compared with a conventional base isolated building, while keeping the acceleration response low, segmentation of the superstructure significantly reduces the base displacement. The result of numerical example shows a 46% reduction in the base displacement for the segmental building when compared with that of the base isolated building.