JP2000283230A - Base isolation device and base isolation structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a base isolating effect obtained by a base isolation device using two sliding members in slidable connect with each other. SOLUTION: This base isolation device comprises a pair of supporting members 18 facing to each other; a first sliding member 20 and a second sliding member 22 respectively supported by both sliding members, and slidably contacted with each other; and a plurality of elastic elements 24 arranged around the first and second sliding members 20, 22, having fixed both ends parts on both supporting members respectively, and exerting a pulling force, acting from one supporting member to the other, on both supporting member. Instead of the plural elastic elements, at least one elastic element surrounding the first and second sliding members 20, 22 can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation device and a seismic isolation structure applied to structures such as buildings and bridges.

[0002]

2. Description of the Related Art Conventionally, two types of sliding members which are slidably in contact with each other have been installed between them to seismically isolate structures on a foundation.

[0003] According to this, the relative movement of the structure with respect to the horizontal movement of the foundation accompanying the occurrence of an earthquake can be increased through the two sliding members.
Seismic isolation of the structure is achieved.

The vertical stress of the structure on the two sliding members contributes to a reduction in the coefficient of kinetic friction therebetween. If the coefficient of kinetic friction between the two sliding members is further reduced, the structure of the structure during an earthquake can be reduced. The relative movement distance of the object can be made larger, so that the seismic isolation effect can be further enhanced.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the seismic isolation effect obtained by a seismic isolation device using two sliding members slidably contacting each other.

[0006]

According to the present invention, there is provided a seismic isolation device for a structure, comprising a pair of support members opposed to each other, and a first support member respectively supported by the two support members and slidably in contact with each other.
And a plurality of elastic bodies disposed around the first and second sliding members and having both ends fixed to the two supporting members, respectively. And a plurality of elastic bodies exerting a tensile force toward each other with respect to each other. In place of the plurality of elastic bodies, a first
And at least one surrounding the two sliding members
One elastic body.

[0007] These seismic isolation devices are arranged between the upper foundation slab and the lower foundation slab opposed to each other at an interval, and both support members of the seismic isolation device are fixed to both foundation slabs. It can be a seismic structure. .

[0008]

According to the present invention, both supporting members for supporting the first and second sliding members of the seismic isolation device are pulled toward each other by an elastic body such as a coil spring. Therefore, both sliding members receive a compressive force toward each other. Therefore, when the seismic isolation device is placed under the structure, the first and second sliding members receive the compressive force of the elastic body and the load of the structure. For this reason, compared with the case where only the load of the structure is received, the two sliding members receive a greater compressive stress, and the dynamic friction coefficient between the two sliding members is smaller. Therefore, it is possible to obtain a higher seismic isolation effect in which the lateral movement amount of the structure with respect to the shaking of the ground is small.

Further, regarding the arrangement of the elastic member, the elastic member may be arranged so as to surround the two sliding members or surround the two sliding members, so that the mutual sliding motion of the two sliding members is not hindered. For example, it facilitates the selection and arrangement of coil springs with a larger spring constant.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 3, there is shown a seismic isolation structure 15 including a part of a structure 14 to which seismic isolation devices 10 and 12 according to the present invention are applied.

Each of the seismic isolation devices 10, 12 has an upper foundation slab 16, which is a part of the structure 14, and faces each other.
And the lower base slab 17.

A seismic isolation device 10 shown in FIG. 1 has a pair of upper and lower support members 18 facing each other, a first sliding member 20 and a second sliding member 22, and a plurality of coils as an example of a plurality of elastic bodies. And a spring 24. On the other hand, the seismic isolation device 12 shown in FIG. 3 differs from the seismic isolation device 10 shown in FIG. 1 only in the number of coil springs 24, which are examples of the elastic body, and in the arrangement thereof.

The support member 18 of each of the seismic isolation devices 10 and 12 includes:
It comprises a plate-like portion 26 and a columnar portion 28 connected to the plate-like portion. The plate-like portion 26 and the columnar portion 28 can be made of, for example, a steel disk and a steel cylinder arranged coaxially with each other.

First and second sliding members 20, 22
Are fixed and supported on free end surfaces (upper end surface and lower end surface) of both columnar portions 28 of both support members 18 facing each other, and slidably contact each other.

In the illustrated example, the upper first sliding member 20 is a single disk, and the lower second sliding member 22 is a rectangular parallelepiped block.

The number of the second sliding members 22 can be a single number, or a plurality of (for example, three) as shown in the illustrated example. Further, the block may be selected from other forms such as a column, for example, instead of the rectangular parallelepiped.

The first and second sliding members 20, 22 are:
They are made of a material that has a dynamic friction coefficient as small as possible when sliding. For example, the first sliding member 20 made of a mirror-finished stainless steel material or a tetrafluoroethylene resin material or the first sliding member 20 made of a steel material coated with a low-friction material (tetrafluoroethylene resin, molybdenum disulfide, etc.) And a second sliding member 22 made of a low friction material such as a tetrafluoroethylene resin material.

The plurality (two in the illustrated example) of the coil springs 24 in the apparatus 10 shown in FIG. 1 are arranged so as to be equally spaced from each other on a circumference around the vertical axis of both support members 18. A pair of upper and lower plate-like portions 2 of both support members 18
6 and both ends of each of the two plate-like portions 26 are provided.
(See FIG. 4).

In the example shown in FIG. 4, in order to fix each end of each coil spring 24 to each plate-like portion 26, each plate-like portion 26
Are provided with a plurality of protrusions 30.

Each of the projections 30 is provided on its peripheral surface with a helical groove 32 which can be engaged with the end of the coil spring 24. It is fixed to the plate portion 26.

The two coil springs 24 are in a state of exerting a tensile force on the two plate-like portions 26, so that the two support members 18 are connected to each other via the two coil springs 24,
Further, the first and second sliding members 20, 22 receive a compressive force toward each other.

Therefore, when the seismic isolation device 10 is disposed between the two base slabs 16 and 17 and the two plate-like portions 26 of the two support members are fixed to the two base slabs 16 and 17, the two sliding members 20 and 22 receives the weight of the structure 14 and the compressive force of the coil spring 24.

Both plate-like portions 26 on both base slabs 16 and 17
For example, the anchor bolts (not shown) provided in the base slabs 16 and 17 are inserted through bolt holes (not shown) provided in the plate-like portions 26 in advance. This can be performed by screwing a nut (not shown) to the anchor bolt.

The first and second sliding members 20, 22 are subjected to a greater compressive stress than if only the weight of the structure 14 acts on them, and therefore both sliding members 20, 22
The coefficient of sliding friction between the two 22 is smaller. As a result, the relative movement amount of the upper foundation slab 16 with respect to the lower foundation slab 17 at the time of an earthquake becomes larger, and a greater seismic isolation effect is exerted.

In the seismic isolation device 12 shown in FIG. 3, a single coil spring 24 coaxially surrounds both the columnar portions 28 of both support members 18 and the two slide members 20 and 22. Both ends of the spring 24 are fixed to both plate-like portions 26 of both support members 18, respectively.

A single coil spring 2 for each plate 26
4 can be fixed in the same manner as in the examples shown in FIGS. However, in the example of FIG. 3, all or a part of each columnar portion 28 that supports the sliding member is accommodated in a hole 34 provided in the projection 30 of each plate-like portion 26 and has a plate-like shape. It is fixed to the part 26.

As in the example shown in FIG. 1, the single coil spring 24 exerts a tensile force on the two plate-like portions 26, so that the first and second sliding members 20, 22 are provided.
Are under compressive force toward each other.

Therefore, when the seismic isolation device 12 is disposed between the two base slabs 16 and 17 and the two plate-like portions 26 of the two support members are fixed to the two base slabs 16 and 17, similarly, the two slides are used. The members 20 and 22 receive the weight of the structure 14 and the compressive force of the coil spring 24.

In order to obtain a greater seismic isolation effect, the magnitude of the compressive stress applied to the sliding members 20 and 22 may be increased. And the set values of the spring constant and the like of the coil spring 24 may be set to be larger, and the set value of the spring constant of the coil spring 24 may be set to be larger in the seismic isolation device 12 of FIG.

In the apparatus 10 shown in FIG. 1, in order to increase the number of coil springs 24 and increase the size of the coil springs 24 in accordance with the increase in the spring constant, the circumference of the circumference on which the plurality of coil springs 24 are arranged is determined. It is necessary to increase the diameter and in the device 12 shown in FIG.
These problems can be easily solved by increasing the size of both plate-like portions 26 of both support members 18 where the diameter of the support members 18 is increased in order to increase the size of the support member 18.

The method or means for solving this problem is the operation of the seismic isolation devices 10 and 12, that is, both sliding members 20 and 22.
Does not hinder the relative movement of The coil spring 2
By setting the spring constant of 4 to a larger one,
The elastically deformed coil spring 24 can apply a greater elastic return force to the sliding members 20, 22 after the relative movement to return the sliding members 20, 22 to the original position.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a seismic isolation device and a seismic isolation structure of the present invention.

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG.

FIG. 3 is a schematic longitudinal sectional view of a seismic isolation device and a seismic isolation structure according to another example of the present invention.

FIG. 4 is a partially enlarged cross-sectional view illustrating an example of a fixing structure of a support member and an elastic body.

[Explanation of symbols]

 10, 12 Seismic isolation device 14 Structure 15 Seismic isolation structure 16, 17 Base slab 18 Support member 20, 22 First and second sliding members 24 Elastic body (coil spring) 30 Projection

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16F 15/06 F16F 15/06 A (72) Inventor Norio Watanabe 2-1 Tsukudocho, Shinjuku-ku, Tokyo Stock (72) Inventor Hiroshi Kita 4-5-33 Kitahama, Osaka-shi, Osaka Sumitomo Metal Industries, Ltd. (72) Inventor Masanobu Okamoto 4-5-33 Kitahama, Osaka-shi, Osaka Sumitomo Metal Industry Co., Ltd. (72) Inventor Kenichi Takizawa 5-1-1109 Shimaya, Konohana-ku, Osaka-shi, Osaka Sumitomo Metal Industries Co., Ltd. Kansai Works Steelworks Office F-term (reference) BC02 BE12 CB01 DA03 EA38

Claims (4)

[Claims] 1. A pair of support members opposed to each other, and a first support member supported by both support members and slidably in contact with each other.
And a plurality of elastic bodies disposed around the first and second sliding members and having both ends fixed to the two supporting members, respectively. And a plurality of elastic bodies exerting a tensile force on each other toward each other. 2. A pair of support members opposed to each other, and a first support member respectively supported by the support members and slidably in contact with each other.
A sliding member and a second sliding member, at least one elastic body surrounding both the first and second sliding members and having both ends fixed to the both supporting members,
A seismic isolation device for a structure, comprising: at least one elastic body that exerts a tensile force on both support members toward each other. 3. The seismic isolation device according to claim 1, which is disposed between an upper foundation slab and a lower foundation slab opposed to each other of the structure and between the two foundation slabs. A seismic isolation structure, including a seismic isolation device fixed to each of the foundation slabs. 4. The seismic isolation device according to claim 2, which is disposed between the upper foundation slab and the lower foundation slab opposed to each other in the structure and between the two foundation slabs. A seismic isolation structure, including a seismic isolation device fixed to each of the foundation slabs.