Shaking table tests with large test specimens of seismically isolated FBR plants, 3; Ultimate behavior of upper structure and rubber bearings

Yabana, Shuichi*; Kanazawa, Kenji*; Nagata, Seiji*; Kitamura, Seiji ; Sano, Takeshi*

This paper describes results of shaking table tests to grasp ultimate behavior of seismic isolation system under extremely strong earthquake motions, including failure of rubber bearings. In the test, lead rubber bearings, of which the diameter is 505 mm and about 1/3 scale of a prototype in planning FBR plants, are used; the test specimens are loaded by the largest three-dimensional shaking table in E-defense of National Research Institute for Earth Science and Disaster Prevention of Japan. Failure of rubber bearings occurs with amplified tentative design earthquake motions. From the tests, the ultimate responses of the upper structure and rubber bearings are presented. In particular, the change of floor response spectra and restoring force characteristics of rubber bearings according to increase of input motions is discussed.