| 摘要 |
PROBLEM TO BE SOLVED: To provide a base isolation structure capable of more freely designing without considering the magnitude of weight of an upper structure. SOLUTION: The arc surface of an upper rolling par 5 provided at the upper end of a pillar body 4 and that of a lower rolling part 6 provided at the lower end of the pillar body 4 are perpendicular to each other in plan view; and the arc surface of the upper rolling part 5 is abutted on the undersurface of an upper structure 2 so as to be capable or rolling. and the arc surface of the lower rolling part 6 is abutted on the upper surface of a lower structure 1 so as to be capable of rolling. so that even if the lower structure 1 is vibrated by earthquake force in the horizontal direction, the upper structure 2 is not vibrated in follow-up thereto and remains nearly in a constant position. Thus, an excellent base isolation effect can be produced. The natural frequency is determined by the vertical length of the pillar 3 and the radii of curvature both of the arc surface of the upper rolling part 5 and of the arc surface of the lower rolling part 6, and is not changed by the mass of the upper structure 2, so that a freer design can be carried out without considering the magnitude of weight of the upper structure 2.
|
