A new type of seismic isolation system-called the core-suspended isolation (CSI) system-has been developed and first building application recently completed. The CSI system consists of a reinforced concrete core on top of which a seismic isolation mechanism composed of a double layer of inclined rubber bearings is installed to create a pendulum isolation mechanism. A multi-level structure is then suspended from a hat-truss or an umbrella girder constructed on the seismic isolation mechanism. In this paper, the mechanics of the CSI system are described, followed by a discussion of results of shaking table tests and quasi-static loading tests of rubber bearings with rotated flanges, and a description of the first building constructed utilizing the CSI system, located in Tokyo, Japan. Figure 22. Velocity response spectra of the synthetic design earthquakes for the site.Figure 23. Upper and lower layer rubber bearing tilt angles and allowable bearing flange rotations.

The Japan Meteorological Agency (JMA) has developed an earthquake early warning system to release information in the event of earthquake, and this system has been in practical use since 2007. Meanwhile, structural health monitoring technology has been attracting attention from those who want to save time in determining the structural health of buildings and who want to detect earthquake resistance performance and damage sustained. Practical applications of this technology have also begun. Seismic-isolated buildings have been developed to protect building structures and keep properties safe from earthquakes and this is significantly effective means to protect properties as a preventative measure against earthquake. The technology is based on the past experiences of the Great Hanshin Earthquake in 1995. Seismic disaster prevention technologies have been further developed since then against the severe, large scale damage to buildings and loss of human life which could be incurred by earthquakes. This should be a system as safe and secure hardware and software as a system in building structures, in addition to the current situation and earthquake disaster prevention of structure itself. This paper describes the earthquake early warning system used to tackle the threat of earthquakes. And the paper shows two applications of the earthquake early warning system and structural health monitoring technologies to seismic-isolated buildings.

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Performance of the super high-rise seismically isolated building during the Great East Japan Earthquake was reported. The response acceleration of the top floor was almost same as that of the 1 st floor. The maximum displacement of the isolation devices was 15 cm, and the cumulative displacement was about 10 m. The dynamic response analysis, considered variation of the characteristic of rubber bearing, ambient temperature and so on, was coincident with observed records.