JPH09184540A - Base isolation supporting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exhibit the damping effect in the range of micro vibration to the large earthquake by providing a lead body filled in a hollow part provided on a load supporting part, and providing an visco-elastic layer surrounded with the load supporting part in the hollow part between the load supporting part and the hollow part with it surrounding the lead body. SOLUTION: When small horizontal displacement acts on a base isolation supporting device 1 through a lower structure by micro vibration or the small earthquake, shear deformation is generated between reinforcing plates 6 of the base isolation supporting device and respective alternately laminated visco-elastic bodies, transmitted to a visco- elastic layer 9 between the inner wall of a hollow part 8 and a lead body 10, and absorbed, and thus the transmission of the vibration to the upper structure is small. When large horizontal displacement acts on the base isolation supporting device 1 through the lower structure by the large scale earthquake, shear deformation is generated on the reinforcing plates 6 and respective alternately laminated visco-elastic bodies 5 and transmitted to the lead body 10 through the visco-elastic layer 9 between the inner wall of the hollow part 8 and the lead body 10. The lead body 10 is plastically deformed by the horizontal displacement and the large scale earthquake is absorbed by the energy loss of the plastic deformation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation support device for protecting a structure from an earthquake, and more specifically, it exerts an excellent damping effect from slight vibrations such as traffic vibrations to medium and large scale earthquakes. Regarding seismic isolation support device.

[0002]

As a seismic isolation support device for protecting a structure from an earthquake, conventionally, a seismic isolation support device, in which a viscoelastic body and a reinforcing plate are alternately laminated, is provided in a laminating direction. Practical use is one in which an energy absorber made of lead is hermetically sealed in the hollow portion.

Such a conventional seismic isolation support device generally determines a damping force and a relative displacement on the assumption of a large-scale earthquake (seismic intensity of 5 or more). Therefore, not to mention slight vibrations such as traffic vibrations. For small and medium-scale earthquakes (seismic intensity 2-4), the equivalent rigidity is large and the natural period is small, so the seismic isolation effect cannot be obtained.

The present invention has been devised in view of the above-mentioned circumstances, and an object of the present invention is to prevent a slight vibration such as a traffic vibration.
It is to provide a seismic isolation support device that exhibits excellent damping effects even for medium- and large-scale earthquakes.

[0005]

In order to achieve the above object, the present invention has the following constitution.

That is, the present invention comprises a load bearing portion formed by alternately laminating viscoelastic bodies and reinforcing plates, and an energy absorbing portion arranged in the load bearing portion. A seismic isolation support device used by being interposed between a structure and an energy absorbing part, wherein the energy absorbing part is a lead body enclosed in a hollow part provided in the load bearing part and the load bearing part in the hollow part. While being surrounded, it also includes a viscoelastic layer that surrounds the lead body and is interposed between the load bearing portion and the lead body. In the case of a relatively small horizontal displacement between them, the horizontal displacement is absorbed by the viscoelastic layer to prohibit the transmission of the horizontal displacement to the lead body. At large horizontal displacements relative to the structure, viscoelasticity To transmit the horizontal displacement into the lead body through the lead body by plastically deforming a seismic isolation support device designed to absorb the horizontal displacement energy by plastic deformation of the lead body.

The viscoelastic layer is formed to have a thickness of 1 to 20 mm in consideration of the diameter of the lead body enclosed in the hollow portion and the amount of vibration displacement which is expected in advance. Further, the viscoelastic body and the reinforcing plate are integrated with each other by vulcanization adhesion, and in this vulcanization adhesion, the viscoelastic layer of the energy absorbing portion is also integrally formed with the load bearing portion.

The viscoelastic layer may have a structure of two or more layers. For example, when the viscoelastic layer has a two-layer structure, the first layer has a small spring constant and the second layer has a large spring constant. The spring constant of the elastic layer is nonlinear. As a result, it is possible to exert a superior damping effect from small vibrations to small-scale earthquakes, medium- and large-scale earthquakes.

Furthermore, by providing a plurality of grooves extending in the laminating direction of the seismic isolation support device on the viscoelastic layer to make the spring constant of the viscoelastic layer non-linear, similar to the above, small vibrations can be avoided. Excellent damping effect can be achieved even for earthquakes and medium- and large-scale earthquakes.

Examples of the viscoelastic body used in the viscoelastic layer include ethylene propylene rubber, nitrile rubber,
A rubber material such as butyl rubber, natural rubber, silicon rubber or polyurethane, a material obtained by mixing a filler such as graphite, carbon black or asphalt with the rubber material, or a sponge material such as foamed polyurethane is used.

According to the present invention, when a small horizontal change acts on the seismic isolation support device due to a slight vibration or a small-scale earthquake, the horizontal displacement causes shear deformation of the seismic isolation support device. The shear deformation hardly acts on the lead body having a large equivalent rigidity enclosed in the hollow portion of the seismic isolation support device, and is absorbed by the viscoelastic layer interposed between the inner wall and the lead body. The seismic isolation support device of the invention exhibits an excellent seismic isolation effect against the slight vibration.

Further, when a large horizontal displacement acts on the seismic isolation support device due to a large-scale earthquake, the horizontal displacement causes shear deformation of the seismic isolation support device. The shear deformation is transmitted to the lead body having a large equivalent rigidity via the viscoelastic layer interposed between the inner wall of the seismic isolation support device and the lead body. The lead body is plastically deformed by the horizontal displacement, and energy loss due to the plastic deformation promptly absorbs a large-scale earthquake and exhibits an excellent seismic isolation effect.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention and the embodiments of the present invention will be described in detail with reference to the preferred embodiments shown in the drawings. The present invention is not limited to these examples.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a seismic isolation support device of the present invention, 1 is a seismic isolation support device, 2 is an upper mounting plate for fixing the seismic isolation support device 1 to an upper structure, and 3 is The seismic isolation support device 1
Is a lower mounting plate for fixing the to the lower structure. The mounting plates 2 and 3 include a plurality of dowel pins 4 for mounting the mounting plates 2 and 3 on the seismic isolation support device 1.

The seismic isolation support device 1 includes a viscoelastic body 5 and a reinforcing plate 6.
And are laminated alternately, and at both ends in the lamination direction,
A reinforcing mounting plate 7 having a hole for fitting the dowel pin 4 is provided. The viscoelastic body 5, the reinforcing plate 6, and the reinforcing mounting plate 7.
After being stacked in a predetermined direction, they are integrated by vulcanization adhesion.

A hollow portion 8 penetrating in the stacking direction is formed in the center of the seismic isolation support device 1, and a lead body 10 having a viscoelastic layer 9 on the periphery is densely formed in the hollow portion 8. It is enclosed. The lead body 10 has a diameter of 50 mm and the viscoelastic layer 9 has a thickness of 5 mm.

The horizontal displacement that occurs in the seismic isolation support device due to a small-scale earthquake is absorbed by the viscoelastic layer 9 with almost no effect on the lead body 10. The viscoelastic layer 9 is integrally formed in advance at the time of the vulcanization adhesion, or is formed by forming a viscoelastic layer around the lead body at the time of encapsulating the lead body and encapsulating together with the lead body.

Next, the operation of the seismic isolation support device 1 of the present invention will be described.

When a small horizontal displacement acts on the seismic isolation support device 1 through the substructure due to a slight vibration or a small-scale earthquake, the viscoelasticity alternately laminated with the reinforcing plate 6 of the seismic isolation support device 1 due to the horizontal displacement. Shear deformation occurs in the body 5. The shear deformation is caused by the inner wall of the hollow portion 8 of the seismic isolation support device 1 and the lead body 10.
Since it is transmitted to the viscoelastic layer 9 interposed between and and is absorbed by the viscoelastic layer 9, the transmission of the horizontal displacement to the superstructure is slight.

When a large horizontal displacement is applied to the seismic isolation support device 1 through the lower structure due to a large-scale earthquake, the viscoelastic bodies alternately laminated with the reinforcing plates 6 of the seismic isolation support device 1 due to the horizontal displacement. Shear deformation occurs in No. 5. The shear deformation is transmitted to the viscoelastic layer 9 interposed between the lead body 10 and the inner wall of the hollow portion 8 of the seismic isolation support device 1. Since the displacement amount of the horizontal displacement is larger than the thickness of the viscoelastic layer 9, the horizontal displacement is transmitted to the lead body 10 via the viscoelastic layer 9. The lead body 10 is plastically deformed by the horizontal displacement, energy loss due to the plastic deformation promptly absorbs a large-scale earthquake, and the horizontal displacement is transmitted to the superstructure slightly.

2 and 3 show the seismic isolation support device 1 of the present invention.
Another embodiment of the viscoelastic layer 11 interposed between the inner wall of the hollow portion 8 and the lead body 10 will be shown.

The viscoelastic layer 11 of this embodiment has a plurality of grooves 12 extending in the direction along the hollow portion 8 of the seismic isolation support device 1. The diameter of the lead body 10 and the thickness of the viscoelastic layer 11 are the same as those in the above-mentioned embodiment, and the groove 1 formed in the viscoelastic layer 11 is the same.
2 has a depth of 2 mm. In this embodiment, the groove 12 having a depth of 2 mm is provided to reduce the spring constant of the viscoelastic layer at the groove forming portion to absorb the minute displacement caused by the minute vibration.

[0023]

The present invention has the following excellent effects by adopting the above constitution. B) By installing a viscoelastic layer between the inner wall of the hollow part of the seismic isolation support device and the lead body, an excellent seismic isolation effect can be achieved from small vibrations caused by traffic vibrations to medium and large-scale earthquake motions. Demonstrate. B) By making the spring constant of the viscoelastic layer non-linear, the seismic isolation effect of microvibration is further improved.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a seismic isolation support device according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view of a seismic isolation support device according to another embodiment of the present invention.

FIG. 3 is a cross-sectional view of the seismic isolation support device shown in FIG.

[Explanation of symbols]

 2 Upper mounting plate 3 Lower mounting plate 5 Viscoelastic body 6 Reinforcing plate 8 Hollow part 9, 11 Viscoelastic layer 10 Lead body 12 Groove

Claims (3)

[Claims] 1. A load bearing portion comprising a viscoelastic body and a reinforcing plate alternately stacked, and an energy absorbing portion disposed in the load bearing portion, and between the upper structure and the lower structure. In the seismic isolation support device, the energy absorbing portion is surrounded by the lead body enclosed in the hollow portion provided in the load bearing portion and the load bearing portion in the hollow portion. It is equipped with a viscoelastic layer that surrounds the lead body and is interposed between the load bearing part and the lead body, and the relative structure between the upper structure and the lower structure due to a slight vibration or a small earthquake. In such a small horizontal displacement, this horizontal displacement is absorbed by the viscoelastic layer to prohibit the transmission of the horizontal displacement to the lead body, and between the upper structure and the lower structure due to a large-scale earthquake that exceeds the horizontal displacement. In the case of large relative horizontal displacement of And transmitting a horizontal displacement, the lead body by plastically deforming, seismic isolation support apparatus adapted to absorb horizontal displacement energy by plastic deformation of the lead body. 2. The seismic isolation support device according to claim 1, wherein the viscoelastic layer has a thickness of 1 to 20 mm. 3. The viscoelastic body of the load bearing portion and the reinforcing plate are integrated with each other by vulcanization adhesion, and the viscoelastic layer of the energy absorbing portion is formed integrally with the load bearing portion. The seismic isolation support device according to 1 or 2.