JP2615644B2 - Seismic isolation device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a seismic isolation device for reducing or preventing vibration of equipment and structures due to an earthquake or the like, and in particular, has both a seismic isolation effect and a damping effect. It relates to an improved seismic isolation device.

[Prior art] A structure (seismic isolation rubber) in which a plurality of steel plates and rubber plates are alternately laminated is used as a support member that satisfies the anti-vibration properties during an earthquake.
It has been receiving attention recently.

When such seismic isolation rubber is interposed between a rigid building structure such as concrete and a foundation, while supporting vertical loads, it is soft in the lateral direction, that is, since the shear rigidity is small, horizontal Has the effect of shifting the natural period of the building from the period of the earthquake, and the acceleration applied to the building by the earthquake becomes extremely small.

A major feature of such seismic isolation rubber is that it undergoes elastic deformation that returns to its original position after deformation due to the earthquake, and furthermore, in order to minimize the settlement of the building due to the creep phenomenon of the seismic isolation rubber. In addition, the energy absorption capacity (damping effect) of the seismic isolation rubber itself is extremely small. For this reason, conventionally, the seismic isolation rubber is configured using a rubber material having a small hysteresis loss as a material characteristic.

However, with such a seismic isolation device using only low-damping seismic isolation rubber, the slow rolling of the building during an earthquake remains for a long time even after the earthquake has subsided. There is a danger that not only will the seismic isolation rubber earthquake be damaged, but also the collision between the building and other structures and the destruction of equipment such as water pipes, gas pipes, and wiring.

Therefore, conventionally, in order to reduce the rolling displacement as soon as possible, a method of absorbing a horizontal swing and performing a plastic deformation immediately when an earthquake force is applied is used together with a damper. The damper is composed of a steel bar or the like, one end of which is connected to a foundation, and the other end of which is connected to a building structure.

[Problems to be Solved by the Invention] Such a conventional damper has an excellent effect in terms of energy absorption during an earthquake. However, a damper such as a steel rod that undergoes plastic deformation through elastic deformation exhibits extremely high rigidity as compared with rubber used as seismic isolation rubber for small deformation.

As a result, even if only a small volume is used compared to the seismic isolation rubber, the presence of the damper significantly increases the horizontal spring stiffness of the seismic isolation device consisting of the seismic isolation rubber and the damper in the micro vibration region. Becomes For this reason, even if it is a seismic isolation rubber which has the effect of damping (vibration-isolating) even minute vibrations when used alone, there is a disadvantage that the natural frequency increases due to the combined use of the damper and the damping effect is lost. .

ICs requiring precision processing as one of the uses of seismic isolation devices
A countermeasure against micro-vibration is applied to factories, bio-factories, laser factories, railways, and houses along roads. However, conventional seismic isolation devices are not suitable for micro-vibration countermeasures.

[Means for Solving the Problems] The present invention solves the above-mentioned conventional problems and provides a seismic isolation device exhibiting a good damping effect even for minute vibrations. In a seismic isolation device including a damper that plastically deforms, at least one of between a damper and a building structure and between a damper and a foundation has a frequency of 5 Hz,
Storage elastic modulus E in dynamic test of 0.01% deformation is 5 × 10 ³ k
The rubber-like elastic body of g / cm ² or less is interposed.

[Action] In the seismic isolation device of the present invention, the seismic isolation rubber supports the vertical load of the building structure and attenuates the vibration at the time of the earthquake by being elastically deformed against the horizontal load.

On the other hand, the damper used together with the seismic isolation rubber has an energy absorption function by plastic deformation, and reduces the roll during an earthquake.

In the present invention, a rubber-like elastic body having a storage elastic modulus E of 5 × 10 ³ kg / cm ² or less in a dynamic test of 5 Hz and 0.01% deformation is interposed between the damper and the building structure or foundation. Therefore, the minute deformation that is transmitted to the building structure through the damper is absorbed by the rubber-like elastic body.

Embodiment An embodiment will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing a seismic isolation device according to one embodiment of the present invention.

The seismic isolation device of the present embodiment includes a seismic isolation rubber 1 that supports a vertical load of the building structure 3 and elastically deforms with respect to a horizontal load.
And a rod-shaped damper 2 that plastically deforms during horizontal deformation. One end 2a of the rod-shaped damper 2 is fixed to the
, But the other end 2b is fitted to the concave portion 7 of the building structure 3 via the rubber elastic body 5.

In the present invention, as the material of the rod-shaped damper 2, for example, a metal such as steel, a ceramic, a plastic, or a rod-shaped material such as FRP that exhibits plastic deformation can be used.

The rubber-like elastic body 5 is (i) a molded article of vulcanized rubber, unvulcanized rubber, plasticized plastic, or the like.

(Ii) Steel, corrugated, honeycomb, fork, and woven materials such as FRP and plastic.

And a storage elastic modulus E in a dynamic test at 5 Hz and 0.01% deformation is E ≦ 5 × 10 ³ Kg / cm ^2, preferably E ≦ 3 × 10 ³ Kg / cm ^{2, and} more preferably E ≦ 1 × 10 ³ Kg / cm ² is used.

In the present invention, there is no particular limitation on the thickness, width, and the like of the rubber-like elastic body 5. It is appropriately determined according to the conditions.

In the illustrated embodiment, one end 2a of the damper 2 is provided.
Is fixed to the base 4, but the damper 2 may be installed on the base 4 side via a rubber-like elastic body, or the rubber-like elastic body may be interposed only on the base 4 side.

In the seismic isolation device of the present invention, the rod-shaped damper 2 may have any shape as long as the energy loss at the time of its shearing deformation or bending deformation can be used well as a damping effect, but a columnar body is generally suitable. ing. The damper used in the present invention is not limited to a columnar shape, but may be a bar-shaped member obtained by bending four rods and setting them in a flower leaflet shape.

In the seismic isolation device of the present invention, the seismic isolation rubber 1 is preferably formed by alternately laminating a plurality of rigid plates 11 having rigidity and soft plates 12 having viscoelastic properties as shown in the figure. . In the figure, 13 and 14 are flanges.

The material of the hard plate 11 constituting the seismic isolation rubber is metal,
Ceramics, plastics, FRP, polyurethane,
Wood, paper board, slate board, decorative board and the like can be used. As the soft plate 12, various kinds of vulcanized rubber, unvulcanized rubber, organic materials such as plastics, foams thereof,
Various materials such as inorganic materials such as asphalt and clay, and mixed materials thereof can be used. These hard plates 11
And the shape of the soft plate 12 is circular, square, other, pentagonal,
It may be a polygon such as a pentagon.

The seismic isolation rubber 1 is easily manufactured by laminating hard plates and soft plates alternately and bonding them by an adhesive or co-vulcanization.

The ratio of the number of arrangements of the seismic isolation rubber 1 and the rod-shaped damper 2 and the arrangement interval are appropriately selected according to the purpose of use of the seismic isolation device.

By the way, in the seismic isolation device of the present invention, a more excellent seismic isolation effect can be obtained by making the following improvements to the seismic isolation rubber 1.

I By coating the outer periphery with a rubber material having excellent weather resistance, weather resistance such as oxidation deterioration resistance, ozone resistance and heat aging resistance can be improved, and durability can be greatly improved.

In addition, such a coating layer of a highly weather-resistant rubber material may be provided on a rod-shaped damper.

II As described above, when the coating layer is provided, the edge of the hard plate is bulged in an arc shape or an arc-like shape, so that excessive stress is applied to the portion of the soft plate in contact with the edge of the hard plate. And distortion can be prevented from being caused in this portion.

III The outer surface of the part of the seismic isolation rubber 1 that comes into contact with the flanges 13 and 14 has a curved surface whose inner surface is curved in an arc shape or arc-like shape so that the cross-sectional area gradually increases toward the flanges 13 and 14. By preventing the local strain from being concentrated near the flange, the maximum local strain is greatly reduced, and the strain is distributed evenly. The problem can be solved.

IV By adopting the following and / or configuration, the occurrence of local strain due to bending deformation of the hard plate near the flange is reduced, and the problem of damage and breakage of the base-isolated structure due to local strain is solved. .

The bending rigidity of the hard plate on the flange mounting side is higher than the bending rigidity of the hard plate on the center side.

The tensile stress of the soft plate on the flange mounting side is higher than the tensile stress of the soft plate on the center side.

V Combine hard plates with different diameters so that at least the portion of the seismic isolation structure that is in contact with the flange gradually increases in cross-sectional area toward the flange, so that its outer surface has an arc-shaped or arc-like shape with a longitudinal cross section inside. By having a curved surface, large local distortion such as maximum local distortion is prevented from being concentrated near the flange, and the distortion is widely and evenly distributed throughout the whole, and the maximum local distortion is greatly reduced. Buckling can be prevented, and problems such as damage and breakage of the seismic isolation structure due to local distortion and buckling can be solved.

VI By making the rigidity of the peripheral part of the seismic isolation structure higher than that of the inner part, large local distortion is prevented from occurring at the peripheral part of the laminated structure, especially the flexible plate, and as a result, the maximum local distortion is greatly increased. It becomes possible to reduce to.

Specifically, the following and / or can be adopted.

The rigidity of the peripheral portion of the soft plate is higher than the rigidity of the inner portion.

The number of laminated hard plates is increased at the periphery of the seismic isolation structure.

[Effects of the Invention] As described in detail above, the seismic isolation device of the present invention has not only the seismic isolation effect but also the damper effect, and the absorption characteristics of minute deformation have a storage elasticity in a dynamic test of 5 Hz and 0.01% deformation. Since the rate E is improved by a rubber-like elastic body of 5 × 10 ³ kg / cm ² or less, extremely excellent vibration can be obtained in a wide range from small vibration such as traffic vibration to small deformation or large deformation due to earthquake. The damping effect is exhibited.

It should be noted that the seismic isolation device of the present invention can be expected to have excellent effects such as vibration isolation (vibration isolation and vibration suppression) in addition to the seismic isolation effect.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a seismic isolation device according to one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Seismic isolation rubber, 2 ... Bar-shaped damper, 3 ... Building structure, 4 ... Foundation, 5 ... Rubber-like elastic body, 6 ... Fixed part, 7 ... Fitting recess, 11 ... Hard Plate, 12 ... Soft plate, 13, 14 ... Flange.

Claims (1)

(57) [Claims] 1. A seismic isolation device installed between a building structure and a foundation, the seismic isolation rubber supporting a vertical load of the building structure and elastically deforming against a horizontal load; In a seismic isolation device having a damper that sometimes undergoes plastic deformation, at least one of between the damper and the building structure and between the damper and the foundation has a storage elastic modulus E in a dynamic test of 5 Hz and 0.01% deformation. A seismic isolation device characterized by interposing a rubber-like elastic body of 5 × 10 ³ kg / cm ² or less.