JP2000064657A - Three-dimensional base isolation device and structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a three-dimensional base isolation device efficiently isolating a base vertically as well as horizontally and eliminating possibility of buckling. SOLUTION: Vertical base isolation can be provided by assembling in series a spherical sliding bearing 10 and a thick-wall laminated rubber 20 whose each rubber layer 21 is designed thick so as to set the natural frequency in the vertical direction less than 10 Hz and at the same time the deformation of the thick-wall laminated rubber 20 is surely settled in a range smaller than the shearing force by which the sliding bearing 10 starts to slide, so that the horizontal allowable deformation can be enlarged without any possibility of buckling. When the vertical movement is amplified within the natural frequency range, an oil damper 30 is attached between the top and bottom flanges 23, 24 of the thick-wall laminated rubber 20 or a vertically tuned mass damper 40 is attached to the building in the upper part of a base isolation layer having a base isolation device I interposed therein so that the short frequency components of the vertical movement can be efficiently cut off.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional seismic isolation device and a three-dimensional seismic isolation structure. In particular, it is capable of seismic isolation not only in the horizontal direction but also in the vertical direction with respect to buildings, building floors, equipment and the like.
The present invention relates to a three-dimensional seismic isolation device and a three-dimensional seismic isolation structure.

[0002]

2. Description of the Related Art In a normally designed seismic isolation structure, the natural frequency in the vertical direction may appear at 10 to 20 Hz, and the response in the vertical direction of large span floors, equipment, pipes, etc. may become large, especially in nuclear facilities. It becomes a big problem in the computer center.

In order to isolate the vibration in the vertical direction as well, it may be considered that the vertical seismic isolation is applied to the inside of the seismic isolation structure independently of the horizontal seismic isolation. If the scale is large, it is economically advantageous to isolate the entire building. As a method to do so, it is conceivable to increase the thickness of each rubber layer and the total rubber layer of the laminated rubber to lower the natural frequency in the vertical direction. Therefore, there is a problem that a large horizontal deformation cannot be taken and the axial force (contact pressure) that can be supported is small, so that the horizontal seismic isolation period does not extend and the seismic isolation effect becomes weak.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to enable effective seismic isolation not only in the horizontal direction but also in the vertical direction, and may cause buckling. It is to provide a three-dimensional seismic isolation device and a three-dimensional seismic isolation structure.

[0005]

A three-dimensional seismic isolation device according to the present invention has a sliding bearing and a vertical natural frequency of 10 Hz.
It is characterized by being combined in series with a thick laminated rubber in which each rubber layer is designed to be thicker than the above.

That is, in the present invention, the natural frequency in the vertical direction is set to 10 Hz by the thick laminated rubber with each rubber layer thickened.
In the case of deformation with sufficient margin for buckling and breaking limit deformation of thick rubber laminated by combining the thick rubber laminated with sliding bearings in series (vertical) while effectively isolating the vertical direction By allowing the sliding bearing to start to slide, the risk of buckling of the thick laminated rubber can be eliminated, and by making the sliding bearing bear most of the horizontal deformation of the seismic isolation layer, only the thick laminated rubber can be It is possible to greatly improve the support capacity when the base isolation layer is largely deformed, compared to the case where it is supported.

The natural frequency of the thick laminated rubber in the vertical direction is
It is set to less than 10 Hz (10 to 20 Hz for conventional laminated rubber) in order to effectively show vertical seismic isolation, but for example, 5 Hz to effectively seismically isolate devices with a natural frequency of 8 Hz or more. It is particularly preferable to set the following.

As the sliding bearing, a known spherical sliding bearing,
A simple sliding bearing or the like can be used, and as the material of the laminated rubber, known natural rubber, high damping rubber, lead-containing rubber, or the like can be used.

In the seismic isolation structure, the vertical movement is amplified near the upper and lower natural frequencies of the thick laminated rubber. In the present invention, this amplification is performed between the upper and lower flanges of the thick laminated rubber. Attaching viscous dampers such as etc. parallel to the axis, or attaching a vertical tuned mass damper that tunes to the vertical natural frequency of the base isolation to the superstructure of the base isolation layer with the above-mentioned three-dimensional base isolation device. Can be effectively suppressed.

[0010]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic explanatory sectional view of a three-dimensional seismic isolation device I according to the present invention. The three-dimensional seismic isolation device I includes a well-known spherical slide bearing 10 selected as a slide bearing and a vertical slide bearing 10 in the vertical direction. Each rubber layer (rubber sheet) 2 compared to general laminated rubber so that the natural frequency is 5 Hz or less (about 4.8 Hz)
This is an example in which the thick laminated rubber 20 designed thicker than 1 is combined in series (vertically) with the former as the upper side (the effect of the invention is also the same as the lower side).

The spherical sliding bearing 10 is a building side footing 1
An upper plate-shaped member 11 fixed to the upper plate-shaped member 11, a lower plate-shaped member 12 fixed to the upper flange 23 of the thick laminated rubber 20, and a movable body 13 interposed between the upper and lower plate-shaped members 11 and 12. Each concave spherical surface 1 of the upper and lower plate-shaped members 11 and 12 facing each other
Teflon-coated steel plates etc. are attached to the movable body 13 as 1'and 12 '.
Teflon or the like is used for each convex spherical surface.

The thick laminated rubber 20 includes a rubber layer 21 and a steel plate 22, which are alternately stacked in a predetermined number, and an upper flange 23.
And the lower flange 24, and the lower flange 24 is fixed to the foundation-side footing 2.

In the three-dimensional seismic isolation device I constructed as described above, the thick laminated rubber 10 having a reduced natural frequency in the vertical direction provides a seismic isolation effect in the vertical direction, and as shown in FIG. Since the deformation of the laminated rubber 20 always falls within a range smaller than the shearing force at which the sliding bearing 10 starts slipping, there is no risk of buckling and the horizontal allowable deformation amount can be increased.

The vertical movement is in the natural frequency range (5H in the above example).
3), the upper and lower flanges 23, 24 of the thick laminated rubber 20 of the three-dimensional seismic isolation device I are amplified.
A plurality of oil dampers 30 as viscous dampers may be attached in parallel with the laminated rubber 20 in between, or as shown in FIG.
As shown in FIG. 4, by providing a seismic isolation structure in which a vertical tuned mass damper 40 that matches the vertical natural frequency of the seismic isolation device I is attached to the bottom of the upper building of the seismic isolation device I , It is possible to effectively cut the short period component of vertical movement.

The vertical oil damper 30 has a small stroke (vertical direction), and the vertical tuned mass damper 40 has a movable weight 4 as is well known.
1, the spring 42 and the damper 43 are used to absorb the vibration energy to the building as the kinetic energy (vertical direction) of the movable weight 41 via the spring 42 and to dissipate it by the damping force of the damper 43.

In the above embodiments, the sliding bearing is the spherical sliding bearing 10, but instead of this, a Teflon sliding member,
Even if a sliding bearing (not shown) made of a stainless plate (sliding mating material) is used, the same effect as the above can be obtained.

[0018]

As described above, according to the present invention, by combining the sliding bearing and the thick laminated rubber in series,
It is possible to obtain a stable three-dimensional seismic isolation device that has a seismic isolation effect not only in the horizontal direction but also in the vertical direction, does not buckle during large horizontal deformation, and does not lose the building load supporting capacity. By adding a viscous damper to the seismic device, or by installing a vertical tuned mass damper on the upper part of the seismic isolation layer, the short-period component of vertical motion is cut and a large horizontal allowable deformation is obtained. It can be a seismic device and a three-dimensional seismic isolation structure.

[Brief description of drawings]

FIG. 1 is a schematic explanatory sectional view of a three-dimensional seismic isolation device according to the present invention.

FIG. 2 is an explanatory cross-sectional view schematically showing a three-dimensional seismic isolation device during horizontal deformation.

FIG. 3 is an explanatory cross-sectional view schematically showing a three-dimensional seismic isolation device equipped with an oil damper during horizontal deformation.

[Fig. 4] 3 with vertical tuned mass damper attached
It is an explanatory cross-sectional view schematically showing a horizontal deformation of the three-dimensional seismic isolation structure.

[Explanation of symbols]

I 3D seismic isolation device 1 Building side footing 2 Foundation side footing 10 Spherical slide bearing 20 thick laminated rubber 21 rubber layer 23 Upper flange 24 lower flange 30 oil damper 40 Vertical tuned mass damper

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI Theme Coat (Reference) F16F 15/04 F16F 15/04 E

Claims (3)

[Claims] 1. A sliding bearing and a vertical natural frequency of 1
A three-dimensional seismic isolation device, characterized in that it is formed by combining in series a thick laminated rubber in which each rubber layer thickness is designed to be thicker than 0 Hz. 2. The three-dimensional seismic isolation device according to claim 1, wherein a viscous damper is attached axially parallel between the upper and lower flanges of the thick laminated rubber. 3. A three-dimensional seismic isolation structure, wherein a vertical tuned mass damper is attached to the upper structure of the seismic isolation layer provided with the three-dimensional seismic isolation device according to claim 1.