JPH11159187A - Seismic isolation mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To add base-isolation mechanism even to a high-rise building which can prevent the breakage of laminated rubber by adding a constraint portion which constrains the separation in up and down directions to the base-isolation mechanism constituted with laminated rubber or the like for damping the interlayer displacement in the horizontal direction. SOLUTION: A base-isolation mechanism 4 comprises a laminated rubber 5 and a constraint portion 6 provided through the center portion, and a damping portion 9 is arranged between an upper plate 7 and a lower plate 8. The constraint portion 6 comprises a rubber damper 14, structure 1, and anchor plugs 15, 15 to be fixed to the foundation. For the rubber damper 14, a rubber material having a large shearing elasticity is used, which has a tensile strength higher than the strength against tensile force in the up-down direction of the laminated rubber 5. A material having a small shearing force is used for a viscoelastic body 11 of the laminated rubber 5. If an external force, which may separate the structure 1 from the foundation 2 in up-down direction, is input, then the rubber damper 14 resists against the tensile force. In this way, the action of a tensile force in up-down direction can be prevented and the breakage of the laminated rubber 5 or the like can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation mechanism suitable for reducing the input of seismic motion in, for example, various structures, particularly, skyscrapers and tower-like structures.

[0002]

2. Description of the Related Art In recent years, various seismic isolation devices have been developed for various structures, such as buildings, in order to minimize shaking during an earthquake and the damage caused thereby.

As this seismic isolation device, a so-called laminated rubber having a structure in which a viscoelastic body and a steel plate are alternately laminated in the vertical direction is frequently used. Laminated rubber, for example, the foundation of the structure,
It is interposed between the structure body built on this foundation,
When a large external force in the horizontal direction is input due to an earthquake or the like, the viscoelastic body is deformed in the horizontal direction to attenuate the external force, thereby suppressing the structure body from shaking.

[0004]

However, the conventional seismic isolation device as described above has the following problems. The laminated rubber that is widely used as a seismic isolation device has a viscoelastic body constituting it that has sufficiently high strength against a compressive force in the vertical direction but low strength against a tensile force. Therefore, when the tensile force in the vertical direction acts excessively on the laminated rubber, the physical property value of the viscoelastic body changes, and the performance cannot be guaranteed, or the viscoelastic body breaks and functions as a seismic isolation device. It is also conceivable that you will not be able to do it. In the case where a large tensile force acts in the vertical direction, the structure to which the seismic isolation device is applied is, for example, a tower-like structure or a skyscraper, or the like, which has a height-to-width ratio (so-called aspect ratio, tower-like ratio). ) Is large, buoyancy is exerted by strong wind from a large roof or the like, or laminated rubber may be arranged on the outer periphery of the building.

[0005] Due to such a problem, conventionally, it is necessary to suppress the aspect ratio of the structure to, for example, about 3 to 3.5 in order to prevent an excessive tensile force from acting on the laminated rubber. This was a major constraint on the design of the seismic structure. However, as is well known, since the Great Hanshin Earthquake, there has been an increasing demand for imparting seismic isolation performance to skyscrapers and buildings having a very large aspect ratio.

The present invention has been made in consideration of the above points, and does not lose the seismic isolation function even when a large tensile force acts in the vertical direction, and has a very high skyscraper and a very high aspect ratio. It is an object to provide a seismic isolation mechanism that can be applied to a large structure or the like.

[0007]

The invention according to claim 1 is
A seismic isolation mechanism that is provided in a seismic isolation layer formed at a predetermined location of a structure and attenuates vibrations acting on the structure, wherein the seismic isolation mechanism includes an upper part, a lower part, and a lower part of the seismic isolation layer. A seismic isolation device that attenuates the horizontal interlayer displacement of the seismic isolation device, and a restraint portion that restrains the upper and lower portions of the seismic isolation layer from being displaced in a direction away from each other in the vertical direction. Is configured so that only horizontal displacement between the upper and lower parts of the seismic isolation layer acts, and no vertical tensile force acts.
In the restraining portion, a tensile resistance member having a tensile strength higher than the seismic isolation device in a vertical direction is fixed to upper and lower ends of the seismic isolation layer at upper and lower ends, respectively. It is characterized by having a configuration.

According to a second aspect of the present invention, in the seismic isolation mechanism according to the first aspect, the tensile resistance member is made of a rubber material having higher tensile strength in the vertical direction than the seismic isolation device.

According to a third aspect of the present invention, in the seismic isolation mechanism according to the first aspect, the tensile resistance member is made of a steel damper having a higher tensile strength in the vertical direction than the seismic isolation device.

[0010] The invention according to claim 4 is the invention according to claims 1 to 3.
The seismic isolation device according to any one of the above, wherein the seismic isolation device is a laminated rubber formed by alternately laminating a viscoelastic body and a steel plate in a vertical direction.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, first and second embodiments of a seismic isolation mechanism according to the present invention will be described with reference to FIGS.

[First Embodiment] First, an example in which, for example, a rubber material is used as a tensile resistance member will be described.

FIG. 1 shows a base portion of a structure such as a building to which the seismic isolation device according to the present invention is applied. In this figure, reference numeral 1 denotes a structure such as a building, and 2 denotes a structure. 1 is a seismic isolation layer provided in a foundation pit between the lower part of the structure 1 and the upper part of the foundation 2, and 4 is a seismic isolation layer installed on the seismic isolation layer 3. Quake mechanism, respectively.

The seismic isolation mechanism 4 includes a column 1 a constituting the structure 1.
And a restraining portion 6 provided to penetrate the center of the laminated rubber 5.

The laminated rubber 5 has the same structure as the conventional one, and has a plate-like upper plate 7 along the lower end surface of the column 1a of the structure 1,
Between the lower plate 8 along the upper surface of the foundation 2, a damping portion 9
Are arranged. The attenuation portion 9 is, for example, circular in cross section,
Steel plate 10 made of, for example, a vibration damping steel plate in addition to a normal steel material
And a viscoelastic body 11 having high damping performance, such as rubber asphalt rubber, high damping rubber, superplastic rubber, etc., are alternately stacked in the vertical direction.

The upper plate 7 and the lower plate 8 of the laminated rubber 5 are in surface contact with the lower surface of the pillar 1a and the plate 12 embedded in the upper surface of the foundation 2, respectively. Is not joined or fixed to the structure 1 or the foundation 2.

The restraining portion 6 includes a rubber damper (tensile resistance member) 14 and anchors embedded in the structure 1 and the foundation 2 to fix the rubber damper 14 to the upper and lower structures 1 and the foundation 2. Plugs 15 and 15 are provided. The rubber damper 14 is housed in a hole 16 formed at the center of the laminated rubber 5 so as to penetrate vertically. The rubber damper 14 is made of a rubber material having a large shear modulus so as to have a higher tensile strength than the tensile strength of the laminated rubber 5 in the vertical direction. Thus, the restraining portion 6 has a higher tensile strength against the vertical tensile force than the laminated rubber 5 itself.

The viscoelastic body 11 of the laminated rubber 5 is made of a material having a small shear modulus and is made as soft as possible. As a result, in the constraining portion 6, the rubber damper 14 is formed of a material having a large shear modulus and is hard and has low horizontal rigidity. However, the entire seismic isolation mechanism 4 including the laminated rubber 5 and the constraining portion 6 is provided. As a seismic isolation cycle can be lengthened.

In the seismic isolation mechanism 4 having such a configuration,
When an external force in the horizontal direction is input to the structure 1 due to an earthquake or the like, the foundation 2 vibrates integrally with the ground and the structure 1 supported on the foundation 2 via the seismic isolation mechanism 4. Horizontal interlayer displacement occurs. Then, in the laminated rubber 5, a shear force is transmitted by a frictional force between the upper plate 7 and the plate 12 on the structure 1 side, and the lower plate 8 and the plate 12 on the foundation 2 side. A relative displacement occurs in the horizontal direction with the lower plate 8 side. This displacement is attenuated by the deformation of each viscoelastic body 11 of the damping section 9.

When an external force is applied so that the structure 1 and the foundation 2 are separated from each other in the vertical direction, the rubber damper 14 fixed to the structure 1 and the foundation 2 by the anchor plugs 15 is provided. It is designed to withstand the tensile force. Further, the laminated rubber 5 is such that the upper plate 7 and the lower plate 8 are only in surface contact with the respective plates 12 of the structure 1 and the foundation 2, respectively. In this configuration, no tensile force is exerted when displacing in the separating direction. Thereby, it is possible to restrain the foundation 2 and the structure 1 from being separated from each other in the vertical direction, and furthermore, the laminated rubber 5 is not subjected to a pulling force in the vertical direction.

As described above, the seismic isolation mechanism 4 is composed of the laminated rubber 5 and the restraining portion 6, and the laminated rubber 5 has a tensile force when the structure 1 and the foundation 2 are displaced in a direction in which they are separated from each other. The rubber damper 14 of the restraining portion 6 has a higher tensile strength than the laminated rubber 5 with respect to the tensile force in the vertical direction. According to the seismic isolation mechanism 4 having such a configuration, when an external force that causes the interlayer between the structure 1 and the foundation 2 to be horizontally displaced due to an earthquake or the like is input, the laminated rubber 5 exerts the seismic isolation effect. Can be. Further, when an external force is input such that the structure 1 and the foundation 2 are relatively displaced in a direction in which the structure 1 and the foundation 2 are vertically separated from each other,
Since the laminated rubber 5 merely comes into surface contact with the structure 1 and the foundation 2 and is not joined, it is possible to prevent a vertical tensile force from acting on the laminated rubber 5. Therefore, the physical property value of the viscoelastic body 11 constituting the laminated rubber 5 changes,
The seismic isolation function can be maintained by preventing damage. Further, the rubber damper 14 of the restraining portion 6 can suppress the relative displacement of the structure 1 in the vertical direction with respect to the foundation 2, so that the structure 1 can be prevented from floating.

As a result, locations and structures to which conventional seismic isolation devices such as laminated rubber could not be applied, such as tower-shaped structures and super-high-rise buildings, etc., having a large tower-like ratio,
It is possible to apply the seismic isolation mechanism 4 to a structure such as a large roof where large buoyancy acts due to strong winds, and to impart seismic isolation performance.

In the first embodiment, the restraining portion 6 is arranged so as to penetrate the center of the laminated rubber 5. However, the structure 1 and the foundation 2 are displaced in a direction in which the structure 1 and the foundation 2 are vertically separated from each other. There is no intention to limit the location and number of installations as long as they can be restricted. For example, as shown in FIG. 2, the laminated rubber 5 and the restraining portion 6 may be separately provided. Also in this case, the laminated rubber 5 is configured such that the upper plate 7 and the lower plate 8 are only brought into surface contact with the structure 1 and the foundation 2 and no tensile force acts in the vertical direction.
There is no change in the configuration in which the upper and lower portions of the rubber damper 14 are fixed to the structure 1 and the foundation 2 by the anchor plugs 15, 15.

[Second Embodiment] Next, a second embodiment of the seismic isolation mechanism according to the present invention will be described. Here, a case in which a steel damper is used as a restraint part constituting the seismic isolation mechanism according to the present invention will be described as an example. In the second embodiment described below, the same reference numerals are given to configurations common to the first embodiment, and description thereof will be omitted.

As shown in FIG. 3, the seismic isolation mechanism 20 provided on the seismic isolation layer 3 of the structure 1 includes a column 1 a constituting the structure 1.
And a constraining portion 21 disposed so as to penetrate the center of the laminated rubber 5.

The restraining portion 21 extends vertically and has a plurality of steel dampers (tensile resistance members) 22 having a tensile strength higher than the tensile strength of the laminated rubber 5 in the vertical direction. In order to fix the end portion to the structure 1 and the foundation 2, it is composed of anchor members 23, 23 buried in the structure 1 and the foundation 2.

Each steel damper 22 has an upper end rotatably supported by an anchor member 23 around its axis so that the restraining portion 21 does not bear a compressive force in a vertical direction, and a ball screw-shaped lower end. The thread 22a is formed to engage with an engaging claw (not shown) provided on the anchor member 23 side. Thus, when a compressive force is applied so that the upper and lower anchor members 23 approach each other, the engagement between the screw 22a at the lower end of each steel damper 22 and the engaging claw (not shown) on the anchor member 23 side is achieved. In this case, while the steel dampers 22 rotate, the engaging claws of the anchor member 23 are displaced along the threads 22a, thereby allowing the upper and lower anchor members 23, 23 to approach each other. I have. The screw 22a of the steel damper 22 is connected to the upper and lower anchor members 2.
3, 23, that is, only when the structure 1 and the foundation 2 are displaced in a direction approaching each other, the engaging claw (not shown)
2a, when the upper and lower anchor members 23, 23 are displaced in a direction away from each other, an engaging claw (not shown) is located at the end of the thread 22a and each steel damper 22 To immediately bear the tensile force.

In the seismic isolation mechanism 20 having such a structure, when the structure 1 and the foundation 2 are displaced horizontally between layers, the laminated rubber 5 attenuates the displacement as in the first embodiment. It has become.

When an external force is applied so that the structure 1 and the foundation 2 are separated from each other in the vertical direction, the laminated rubber 5 is joined to the structure 1 and the foundation 2 as in the first embodiment. As a result, no vertical pulling force is applied. And the anchor members 23, 23
Accordingly, the steel damper 22 fixed to the structure 1 and the foundation 2 resists the tensile force.

The same effect as that of the first embodiment can be obtained by the seismic isolation mechanism 20 having the restraining portion 21 having the above-described configuration.

In the second embodiment, the restraining portion 21 is arranged to penetrate the central portion of the laminated rubber 5 and is arranged. However, the restraining portion 21 is different from that shown in FIG. 2 in the first embodiment. Similarly, if the structure 1 and the foundation 2 can be restrained from being displaced in the direction in which the structure 1 and the foundation 2 are vertically separated from each other, there is no intention to limit the installation position and the number thereof. For example, as shown in FIG. It is good also as composition which installs and restraint part 21 separately. Also in this case, the laminated rubber 5 is configured such that the upper plate 7 and the lower plate 8 are only brought into surface contact with the structure 1 and the foundation 2 and no tensile force is applied in the vertical direction.
Are anchor members 23, 2 above and below the account damper 22.
There is no change in the configuration in which the fixing is performed on the structure 1 and the foundation 2 in 3.

In the first and second embodiments, the seismic isolation mechanisms 4 and 20 are installed between the foundation 2 and the structure 1. However, the installation floor is not limited at all. . Further, the configuration and the number of the laminated rubber 5 and the restraining portions 6 and 21 may be different from those described above. For example, the configuration may be such that the restraining portions 6 and 21 are provided not only at the center or both sides of the laminated rubber 5 but also at three or four sides.

In addition, although the laminated rubber 5 is used as an example of the seismic isolation device constituting the seismic isolation mechanism according to the present invention, other seismic isolation devices having a horizontal seismic isolation function are employed. It is also possible.

Other than this, any configuration may be adopted as long as it does not deviate from the gist of the present invention, and it is needless to say that the above-described configurations may be selectively combined appropriately. No.

[0035]

As described above, claims 1 to 3 are described.
According to the seismic isolation mechanism according to the above, the seismic isolation device that attenuates the horizontal interlayer displacement between the upper and lower parts of the seismic isolation layer, and the upper and lower parts of the seismic isolation layer are displaced in directions that are separated from each other in the vertical direction The seismic isolation device has a structure in which the vertical tension between the upper and lower parts of the seismic isolation layer does not act, and the restraining portion has a more vertical tension than the seismic isolation device. Tensile resistance members having high tensile strength with respect to force, for example, rubber materials and steel dampers, are provided with their upper and lower ends fixed to the upper and lower portions of the seismic isolation layer, respectively. Furthermore, according to the seismic isolation mechanism of the fourth aspect, the seismic isolation device is configured to be a laminated rubber in which a viscoelastic body and a steel plate are alternately laminated in the vertical direction. According to the seismic isolation mechanism having such a configuration, when a horizontal external force is input to the seismic isolation device due to an earthquake or the like, the displacement is attenuated by the seismic isolation device such as a laminated rubber to exhibit the seismic isolation effect. Can be. In addition, when a displacement occurs such that the upper and lower parts of the seismic isolation layer are separated from each other, the upper and lower parts of the seismic isolation device are configured so that the vertical pulling force does not act. It is possible to prevent a tensile force from acting. Therefore, for example, breakage of the seismic isolation device such as a laminated rubber can be prevented, and the seismic isolation function can be maintained. Moreover,
The lifting of the structure can be prevented by the restraining portion. With such a seismic isolation mechanism, places and structures where conventional seismic isolation devices such as laminated rubber could not be applied, such as tower-shaped structures and structures with a large tower-like ratio such as super-high-rise buildings Also, it is possible to impart seismic isolation performance to a structure such as a large roof where large buoyancy acts due to strong wind.

[Brief description of the drawings]

FIG. 1 is an elevational sectional view showing a first embodiment of a seismic isolation mechanism according to the present invention.

FIG. 2 is a vertical sectional view showing another example of the seismic isolation mechanism shown in the first embodiment.

FIG. 3 is an elevational sectional view showing a second embodiment of the seismic isolation mechanism according to the present invention.

FIG. 4 is an elevational sectional view showing another example of the seismic isolation mechanism shown in the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Structure 3 Seismic isolation layer 4, 20 Seismic isolation mechanism 5 Laminated rubber (isolation device) 6,21 Restraint part 14 Rubber damper (tensile resistance member) 22 Steel damper (tensile resistance member)

Claims (4)

[Claims] 1. A seismic isolation mechanism provided on a seismic isolation layer formed at a predetermined position of a structure, wherein the seismic isolation mechanism attenuates vibrations acting on the structure, wherein the seismic isolation mechanism comprises: A seismic isolation device that attenuates horizontal interlayer displacement between the upper part and the lower part, and a restraint part that restrains the upper part and the lower part of the seismic isolation layer from being displaced in a direction away from each other in the vertical direction. The seismic isolation device is configured so that only horizontal interlayer displacement between the upper and lower portions of the seismic isolation layer acts, and no vertical tensile force acts. A tensile resistance member having a high tensile strength with respect to a tensile force in one direction, wherein upper and lower ends thereof are fixed to upper and lower portions of the seismic isolation layer, respectively. mechanism. 2. The seismic isolation mechanism according to claim 1, wherein the tensile resistance member is made of a rubber material having a higher tensile strength in the vertical direction than the seismic isolation device. 3. The seismic isolation mechanism according to claim 1, wherein the tensile resistance member is made of a steel damper having a higher tensile strength in the vertical direction than the seismic isolation device. 4. The seismic isolation device according to claim 1, wherein the seismic isolation device is a laminated rubber obtained by alternately laminating a viscoelastic body and a steel plate in a vertical direction. Seismic isolation mechanism.