THREE-DIMENSIONAL BASE ISOLATION SYSTEM

PROBLEM TO BE SOLVED: To prevent or restrain a rocking movement of a large-scale top structure base-isolated with a three-dimensional base isolation device. SOLUTION: This three-dimensional base isolation system comprises a three-dimensional device 3 arranged between a top structure 1 and a bottom structure 2 and base-isolating the top structure 1 in a horizontal direction and a vertical direction. A pair of oil dampers comprising a first oil damper 4A arranged at a corner position of the top structure 1 in plan view and attenuating vertical vibrations and a second oil damper 4B arranged at a position diagonal to the corner position and attenuating vertical vibrations are provided between the top structure 1 and the bottom structure 2. An upper oil tank chamber of the first oil damper 4A is communicated with a lower oil tank chamber of the second oil damper 4B via a first hydraulic pipe 5, and a lower oil tank chamber of the first oil damper 4A is communicated with an upper oil tank chamber of the second oil damper 4B via a second hydraulic pipe 6. COPYRIGHT: (C)2009,JPO&INPIT