MULTI-STAGE BASE ISOLATION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a multi-stage base isolation device which more efficiently and rationally suppresses a tremor that affects a heavy construction and the like at the time of an earthquake and avoids damage and the like of the construction in the multi-stage base isolation device made up of unit base isolation devices and connection members. SOLUTION: In the multi-stage base isolation device in which plural pieces of laminated rubbers 2 per stage are arranged in multiple stages via the connection members 3, the laminated rubbers 2 of the upper stage and the laminated rubbers 2 of a lower stage are arranged so as to be displaced from each other and their plane cross sections are made to overlap partially. By making the plane cross sections of the laminated rubbers 2 of the upper and lower stages overlap partially, stress is transmitted in the vertical direction from the laminated rubbers 2 of the upper stage to the laminated rubbers 2 of the lower stage via the connection members 3. The device is excellent in stability because the overlapped portions transmit the stress in the vertical direction straight. In addition, a difference of dynamic characteristics in the horizontal direction can be made small as plane cross sections of the laminated rubbers 2 are displaced in the upper and lower stages. Thus, directivity can be eliminated and efficient base isolation becomes possible. COPYRIGHT: (C)2011,JPO&INPIT