JP2000130506A - Three-dimensional base isolation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make three-dimensional base isolation so as to be well-balanceably and smoothly performable, insomuch that a vertical spring constant is sharply reducible as an average horizontal spring constant, and a vertical shake in time of an earthquake is made to be long-periodizable at the same level as that in the horizontal direction, etc. SOLUTION: A horizontal motion base isolating body 3 and a vertical motion base isolating body 5 are vertically connected together. This horizontal motion base isolating body 3 is provided with a first layered product wherein both horizontal hard and soft plates 6 and 7 are alternately laminated. Likewise, the vertical motion base isolating body 5 is provided with a second layered product 4 wherein both vertical hard and soft plates are alternately laminated at the outside from the inside, the outer periphery of a vertical center axis 14A, and a mounting base 17 with a recess 16 inserting this second layered product 4 and supporting its outer periphery, respectively. This center axis 14A is integrated with a mounting plate part 14B to be attached to a structural body 10U. There is a gap provided in a space between an innermost surface of the recess 16 and the second layered product 4.

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 capable of exerting the same smooth seismic isolation effect as in a horizontal direction even in the event of an earthquake.

[0002]

2. Description of the Related Art Generally, in a normal earthquake, a short-period component having a period of 1 second or less is predominant in many cases. Because of having a natural frequency close to the period of, it is easy to receive a large seismic force. Therefore, it is necessary to reduce the seismic force by extending the natural period of the building to the level of a super-high-rise building. For this purpose, vulcanization is performed by alternately stacking hard plates such as steel plates and rubber-elastic soft plates. Glued laminated rubber bearings have been proposed.

[0003] Since this type has a soft spring property in the horizontal direction due to a soft plate, it has a long cycle in the horizontal direction, and is effective in reducing the horizontal response acceleration during an earthquake. Also, for vertical loads, the rigid plate restrains it from spreading at a right angle to it, so it has high rigidity, so it has the property of stably supporting the weight of the building for a long period of time, but on the vertical direction The behavior is almost the same as in the case of non-seismic isolation.

However, according to recent reports, earthquakes that have extremely large vertical and vertical motions have been observed. For example, in the case of the Great Hanshin Earthquake, the maximum acceleration was 507 Gal at maximum in the vertical direction (833 Gal in the horizontal direction). And big,
It is also reported that horizontal movement and vertical movement occurred almost simultaneously in a short time of about 10 to 15 seconds. That is, it is considered that a large force was instantaneously applied from both the horizontal direction and the vertical direction.

Therefore, in recent years, means for responding to such an earthquake directly under the city has been strongly desired.

Japanese Patent Laid-Open Publication No. 6-264643, for example, discloses, as schematically shown in FIG. 10, an upper portion of a laminated rubber bearing (thin laminated rubber a) for horizontal motion seismic isolation having substantially the same configuration as the conventional one. And a vertical rubber seismic isolation rubber bearing (thick laminated rubber b) with reduced vertical rigidity using a soft plate b1 with a large rubber thickness
Have been proposed.

However, in this case, the vertical spring constant of the thick laminated rubber b for vertical seismic isolation depends on the rubber compression elasticity of the soft plate b1. It becomes very large compared to the horizontal spring constant. As a result, there is a problem in that the seismic isolation against three-dimensional shaking during an earthquake impairs smoothness.

Accordingly, the present invention provides a structure in which the vertical spring constant is reduced substantially to the same level as the horizontal spring constant, and the vertical sway during an earthquake is made longer at the same level as the horizontal direction.
The purpose is to provide a three-dimensional seismic isolation device that can smoothly perform three-dimensional seismic isolation in a well-balanced manner.

[0009]

In order to achieve the above object, the invention of claim 1 of the present application is a three-dimensional seismic isolation device for isolating relative horizontal and vertical movements of upper and lower structures, A horizontal seismic isolator having a first laminate in which horizontal hard plates and soft plates are alternately stacked up and down; and a vertical hard plate and a soft plate extending from the inside to the outside on the outer periphery of the vertical center shaft portion. A vertically moving seismic isolator having a second laminated body alternately laminated outward and a mounting base having a recessed portion into which the second laminated body can be inserted and which supports the outer periphery thereof is vertically connected. The central shaft portion is integrated with a mounting plate portion attached to the structure, and a gap is provided between the inner surface of the concave portion and the second laminate.

[0010] In the invention of claim 3 of the present invention,
The soft plates of the first laminate and the second laminate are made of high-damping rubber, or through holes vertically penetrating the first laminate, and the second laminate is defined as the central shaft portion. It is characterized in that an attenuating material is loaded in a through-hole passing through horizontally with the mounting base.

In the invention of claim 3,
A cushioning member made of an elastic-plastic material is interposed between the mounting plate and the mounting base.

Further, in the invention of the three-dimensional seismic isolation device of claim 4,
The hard plate and the soft plate of the second laminate are formed in a cylindrical shape, or are composed of a flat hard plate and a soft plate, and are radially arranged at an equal angular pitch from the central axis portion. It is characterized by consisting of.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, a three-dimensional seismic isolation device 1 of the present invention includes a horizontal seismic isolator 3 having a first laminate 2.
And a vertical seismic isolator 5 having a second laminated body 4 and connected above or below the horizontal seismic isolator 3.

The horizontal vibration isolator 3 comprises a plurality of horizontal hard plates 6 and soft plates 7 alternately laminated and bonded to each other.
, And supporting plates 9U and 9L fixed above and below the first laminated body 2 by, for example, bolts. In this example, the upper and lower supporting plates 9U and 9L It is integrally connected to the motion isolator 5 and a lower structure 10L which is a foundation of a building, for example.

The first laminate 2 has a soft spring property in the horizontal direction due to rubber elasticity in the shearing direction of the soft plate 7, has a long cycle in the horizontal direction, and effectively reduces the response acceleration in the horizontal direction. Reduce. For vertical load in the vertical direction,
Since the hard plate 6 bonded to the soft plate 7 restrains the spread of rubber due to compression, the rigid plate has high rigidity, and therefore can stably support the weight of the building for a long period of time.

The hard plate 6 is made of a rigid metal plate such as a steel plate. The upper and lower hard plates 6U and 6L disposed at the uppermost and lowermost stages are thicker than the intermediate hard plate 6M. For example, the support plates 9U and 9L are formed to have substantially the same thickness. As long as the plate has the same rigidity and strength as the metal plate, plates made of various materials such as ceramics and synthetic resin can be used. Hard plate 6
It is preferable that the shape of the outer peripheral surface, that is, the contour shape of the outer edge is a circular shape without directivity, so that it can cope with shaking in various directions.
It can also be formed in a polygonal shape such as a pentagon.

As the soft plate 7, various rubber compositions having rubber elasticity can be used, but they are excellent in mechanical strength, long-term stability of elastic modulus, long-term stability of deformability, creep resistance, and the like. Is required, for example, natural rubber (NR),
Chloroprene rubber (CR) can be preferably used. The thickness of the soft plate 7 is usually about 1.0 to 2.5 times the thickness of the intermediate hard plate 6M, and in this example, 1.0 to 1 times.
Rubber of about 0.0 mm is used.

Further, in the present embodiment, the horizontal motion isolator 3 is provided with a through hole 11 vertically penetrating the first laminated body 2, and in this through hole 11, for example, a lead plug or a high attenuation By loading the damping material 12 having a high damping performance such as rubber, the amplitude of the horizontal swing is limited and the quick convergence is achieved. The damping material 12 is sealed by the caps 13 disposed at the upper and lower ends of the hole 11 as described above. Instead of loading the damping material 12, the soft plate 7 itself may be formed of high damping rubber.

Next, as shown in an enlarged view in FIG. 2, the vertical seismic isolation body 5 has a mounting plate 14 mounted on the upper structure 10U and an outer periphery of a central shaft portion 14A of the mounting plate 14. Mounting base 1 having a second laminated body 4 to be arranged and a concave portion 16 for inserting the second laminated body 4 and supporting the outer periphery thereof
7 and so on.

The mounting plate 14 is a mounting plate portion 14B fixed to the upper structure 10U, which is a building, for example, by bolts or the like.
In this example, the central shaft portion 14A is formed integrally with the mounting plate portion 14B and extends vertically.
The mounting plate portion 14B and the central shaft portion 14A may be formed integrally or may be fixed integrally with bolts or the like.

The mounting base 17 is bolted to the upper support plate 9U using a lower flange portion 17A, and has a concave portion 16 for accommodating the second laminated body 4 at the upper end.
Is formed.

The mounting plate portion 14B and the mounting base portion 17
In this example, a cushioning member 21 that carries a normal long-term vertical load (such as the weight of a building) is interposed in a ring shape.
Thereby, a gap G1 is formed between the inner surface (bottom surface) 16S of the recess 16 and the lower end surface of the central shaft portion 14A. The shock absorbing member 21 is made of an elasto-plastic material capable of causing a plastic deformation of compression and absorbing a part of the impact energy when a vertical shock exceeding the long-term vertical load acts upon an earthquake. , High-attenuation plastic, natural rubber and the like are used.

The second laminate 4 is formed by alternately laminating and bonding a plurality of vertical hard plates 19 and soft plates 20 from the inside to the outside around the central shaft portion 14A. , The innermost soft plate 20 is the central shaft portion 14A.
, The inner periphery of the second laminate 4 is supported on the outer periphery of the central shaft portion 14A. Also the outermost hard plate 19A
Is thicker than the other hard plate 19B, and the outermost hard plate 19A is bolted to the inner peripheral surface of the recess 16 so that the outer periphery of the second laminate 4 is Supported by

At this time, a gap for vertical vibration is provided between the upper end surface of the second laminate 4 and the mounting plate portion 14B, and between the lower end surface and the inner surface 16S of the recess 16 respectively. It is necessary to form G2 and G3. In this example, in order to firmly support the outermost hard plate 19A and secure the gap G3, the pedestal portion 16A that receives the lower end surface of the hard plate 19A is raised from the inner surface 16S of the recess 16. ing. In this example, the lower end surfaces of the second laminated body 4 and the central shaft portion 14A are substantially aligned, so that
The case where the gaps G1 and G3 substantially match is illustrated.

The hard plate 19 and the soft plate 20 are the same as those shown in FIG.
It is preferable to use a cylindrical member concentric with the central shaft portion 14A as shown in FIG. However, as shown in FIG. 4, for example, when the central shaft portion 14A has a polygonal shape, such as a square cross section, a flat hard plate 19 and a soft plate 20 are used, and these are removed from the central shaft portion 14A. The second laminate 4 can be formed by a plurality of laminate pieces 22 radially arranged at an angular pitch. This plurality of laminate pieces 2
The structure using 2 is simple in manufacturing, and has a great advantage in improving production efficiency and production cost.

As the hard plate 19, similarly to the hard plate 6, a rigid metal plate such as a steel plate can be preferably used. As the soft plate 20, various rubber compositions having rubber elasticity can be used as in the case of the soft plate 7. At this time, the thickness ratio between the hard plate 19 and the soft plate 20 is 1.0 to 1.0.
It is better to be in the range of 2.5. The thickness of the soft plate 20 is usually set to 1.0 to 10.0 mm.

The second laminated body 4 has a soft elasticity in the vertical direction due to the rubber elasticity of the soft plate 20 and has a long period in the vertical direction, contrary to the first laminated body 2. The response acceleration is effectively reduced. Also, there is no fluctuation because the rigidity is high in the horizontal direction which is the laminating direction, and therefore, the mounting plate 14, that is, the upper structure 10U is stably moved up and down with respect to the mounting base 17 without providing a dedicated guide means. I can guide you.

As shown in FIGS. 7 and 8, the vertical motion isolator 5 is attached to the second shaft 4 by the central shaft portion 14A.
A through-hole 24 is provided between the mounting base 17 and the mounting base 17, and a damping material 25 similar to the damping material 12 is loaded in the through-hole 24 to limit the amplitude of the vertical swing. It is preferable to achieve quick convergence. Instead of loading the damping material 25, the soft plate 20 itself may be formed of high damping rubber.

However, the vertically-moving seismic isolation body 5 stably supports the normal long-term vertical load by the cushioning member 21 made of an elastic-plastic body. Therefore, the long-term vertical load is not substantially applied to the second laminate 4 and the viscoelastic properties of the second laminate 4 can be maintained for a long time without causing fatigue deterioration.

When a vertical impact exceeding the long-term vertical load is applied, as shown in FIG. 5, the cushioning member 21 undergoes plastic deformation by compression and absorbs a part of the impact energy. At this time, the second laminated body 4 is also effective for shock relaxation, and after the initial shock relaxation, has a very smooth response such as starting to move softly due to a low vertical spring constant and prolonging the vertical swing. .

In particular, since the vertical spring constant and the horizontal spring constant of the first laminate 2 can be close to each other, the vertical oscillation can be made longer at substantially the same level as the horizontal oscillation. As a result, three-dimensional seismic isolation can be performed in a well-balanced and smooth manner.

In the three-dimensional seismic isolation device 1, as shown in FIG. 6, a protection member 26 is provided to cover the outer periphery of the vertically movable seismic isolator 5 and protect the soft plate 20 and the buffer member 21 and the like inside from a flame or the like. be able to. At this time, it is necessary to take care that the protection member 26 does not affect the vertical spring constant of the vertical seismic isolation body 5.

In the three-dimensional seismic isolation device 1 of the present invention, as shown in FIG. 9, a plurality of vertically movable seismic isolation bodies 5 may be formed around the center of the mounting base 17, and a plurality of horizontally movable The seismic isolation body 3 can be formed around the center of the support plate 9.

The vertical seismic isolator 5 may be connected to the lower side of the horizontal seismic isolator 3. Further, the three-dimensional seismic isolation device 1 of the present application can be formed in various forms, such as the up-down motion seismic isolator 5 can be formed upside down, that is, the central shaft portion 14A extends upward and the recess 16 opens downward. It can be changed to an aspect.

[0035]

Since the present invention is configured as described above,
Structurally, the vertical spring constant can be reduced as much as the horizontal spring constant, and the vertical shaking during an earthquake can be lengthened at the same level as the horizontal direction. Can be performed.

[Brief description of the drawings]

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

FIG. 2 is an enlarged vertical sectional view of the vertical motion seismic isolation body.

FIG. 3 is a cross-sectional view illustrating an example of a second laminate.

FIG. 4 is a cross-sectional view showing another example of the second laminate.

FIG. 5 is an exaggerated longitudinal sectional view showing the operation of the vertical motion isolators.

FIG. 6 is a longitudinal sectional view showing another example of the vertical seismic isolation body.

FIG. 7 is a cross-sectional view showing still another example of the second laminate.

FIG. 8 is a cross-sectional view showing still another example of the second laminate.

FIG. 9 is a cross-sectional view showing another example of the seismic isolation device.

FIG. 10 is a longitudinal sectional view of a seismic isolation device showing a conventional technique.

[Explanation of symbols]

 2 First laminated body 3 Horizontal seismic isolator 4 Second laminated body 5 Vertical seismic isolator 6 Hard plate 7 Soft plate 10U, 10L Upper and lower structures 11, 24 Through holes 12, 25 Damping material 14A Central axis Part 14B Mounting plate part 16 Concave part 17 Mounting base 19 Hard plate 20 Soft plate 21 Buffer member 22 Laminate piece G1, G2, G3 Gap

Claims (4)

[Claims] 1. A three-dimensional seismic isolator for isolating relative horizontal and vertical movements of upper and lower structures, comprising: a first stacked body in which horizontal hard plates and soft plates are alternately stacked up and down. A horizontal seismic isolation body having a second laminated body in which a hard plate and a soft plate which are vertically arranged from the inside to the outside are alternately and outwardly laminated on the outer periphery of a vertical central shaft portion, and the second laminated body A vertically movable seismic isolator including a mounting base having a concave portion that can be inserted and supports the outer periphery thereof is vertically connected, and the central shaft portion is integrated with a mounting plate portion mounted on the structure, and A three-dimensional seismic isolation device, wherein a gap is provided between an inner surface of the recess and the second laminate. 2. The soft plate of the first laminate and the second laminate is made of high-damping rubber, or a through hole vertically penetrating the first laminate, and The three-dimensional seismic isolation device according to claim 1, wherein a damping material is loaded in a through hole that horizontally penetrates between the central shaft portion and the mounting base. 3. The three-dimensional seismic isolation device according to claim 1, wherein a cushioning member made of an elastic-plastic material is interposed between the mounting plate and the mounting base. 4. The hard plate and the soft plate of the second laminate are cylindrical or consist of a flat hard plate and a soft plate, and are arranged radially at an equal angular pitch from the central axis. 4. A laminated piece to be formed.
The three-dimensional seismic isolation device described.