| 摘要 |
PROBLEM TO BE SOLVED: To provide a base isolation structure by which the constitution of a pull-out preventive device is simplified and the preventive device has no influence on the behavior of the base isolation device by using a spring member adding a prestress between a foundation and an objective body and having a constant load range in which load variation against the extension and contraction quantity of the spring member is slight. SOLUTION: An objective body 3 for base isolation is supported on a foundation 1 through a base isolation device 2. A pull-out preventive device 4 resisting against a pull-out force acting in between the foundation 1 and the objective body 3 is installed therebetween. The pull-out preventive devive 4 is constituted of a spring member 5 provided with a constant load range where the load variation against the vertical displacement is slight. A prestress resistant against a pull-out force is added in between the foundation 1 and the objective body 3 within a constant load range of the spring member 5.
|
