JP3733507B2 - Seismic isolation structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a seismic isolation structure that is installed in a building and reduces input to the building due to earthquake vibration.
[0002]
[Prior art]
As is well known, various types of seismic isolation structures have been realized to reduce building vibration response by interposing a laminated rubber bearing between the building foundation and the upper structure to insulate the upper structure from the ground. ing.
Such seismic isolation structure has an excellent effect that can greatly reduce the vibration response of buildings, so its application range is gradually expanding, especially in high-rise buildings that could not be applied conventionally Also, it has been adopted for buildings with a large aspect ratio (building height / building width).
[0003]
[Problems to be solved by the invention]
In these high-rise buildings and buildings with a large aspect ratio, there is a risk of pulling force acting on the seismic isolation device at the end of the building in the event of a large earthquake. In this case, resistance to tensile force cannot generally be expected from laminated rubber bearings. Therefore, it was necessary to provide a stopper capable of resisting the pulling force separately from the laminated rubber bearing.
[0004]
FIG. 3 is a view showing an example of such a stopper. In the figure, reference numeral 1 denotes a base of a base-isolated building, and 2 denotes an upper structure supported by the base 1 via a base-isolation device (not shown). Show. The stopper 3 is fixed to a support base 4 provided on the foundation 1, and includes a cylindrical main body 3a and a flange 3b provided on the upper end of the main body 3a. The upper structure 2 is provided with an insertion hole 6, and the main body 3 a of the stopper 3 is inserted into the insertion hole 6.
[0005]
In the event of an earthquake, the stopper 3 is displaced horizontally in the insertion hole 6 so as to allow the horizontal movement of the foundation 1 and the upper structure 2 and the foundation 1 and the upper structure 2 are vertically moved. When it is displaced so as to be separated from each other, the upper structure 2 and the flange 3b of the stopper 3 come into contact with each other, thereby functioning to resist pulling.
[0006]
However, such a stopper 3 may be damaged by a collision between the inner surface of the insertion hole 6 and the stopper 3 during a large earthquake, or hinder the relative movement of the upper structure 2 and the foundation 1 in the horizontal direction. There was a problem of acting and reducing the function of the seismic isolation structure.
[0007]
In view of such circumstances, it is an object of the present invention to provide a seismic isolation structure that can resist a pulling force with a simple configuration and that is safer than conventional ones.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the present invention employs the following means.
That is, in the seismic isolation structure according to claim 1, a laminated rubber formed by laminating a plurality of plates and rubber is interposed between the lower structure and the upper structure of the building,
Between the lower structure and the upper structure, there is provided a pull-out preventing member that restricts the relative displacement in the direction in which the lower and upper structures are separated and allows the relative displacement in the horizontal direction.
Between the pull-out prevention member and the laminated rubber, in a seismic isolation structure provided with a spacing member that keeps a horizontal distance between them constant ,
The laminated rubber, when viewed from above, has a through hole at the center thereof,
The pull-out prevention member is inserted into the through hole,
The spacing member is integrated with a part of the plate constituting the laminated rubber .
[0009]
In this seismic isolation structure, the pull-out prevention member can be displaced corresponding to the relative displacement in the horizontal direction between the lower structure and the upper structure. There is no risk of collision with the superstructure or substructure.
Further, in this seismic isolation structure, the laminated rubber and the pull-out preventing member can be integrally manufactured.
[0010]
The seismic isolation structure according to claim 2 is the seismic isolation structure according to claim 1,
The laminated rubber is provided between a lower flange fixed to the lower structure side and an upper flange fixed to the upper structure side,
The pull-out prevention member is configured to contact the lower flange from the lower surface side and from the upper surface side to the upper flange so as to be relatively displaceable in the horizontal direction.
[0011]
Since it is set as such a structure, this seismic isolation structure can exhibit a pull-out prevention function with a simple structure.
[0014]
Seismic isolation structure according to claim 3 wherein is a seismic isolation structure according to claim 1 or 2,
The pull-out preventing member is formed of a material that can be plastically deformed when a force greater than a predetermined force is applied in a direction in which the upper structure and the lower structure are separated from each other.
[0015]
Because of such a configuration, in this seismic isolation structure, even when a pulling force exceeding a predetermined allowable pulling load is applied, the pulling resistance is not suddenly lost.
[0016]
The seismic isolation structure according to claim 4 is the seismic isolation structure according to claim 3 ,
The pull-out preventing member and the interval holding member are configured to be in contact with each other so as to be relatively displaceable in the vertical direction.
[0017]
Because of such a configuration, in this seismic isolation structure, even if the pull-out prevention member is deformed in the vertical direction, this does not adversely affect the laminated rubber side.
[0018]
The seismic isolation structure according to claim 5 is the seismic isolation structure according to any one of claims 2 to 4 ,
At least one of the upper surface of the upper flange and the lower surface of the lower flange and the pull-out preventing member constitute a friction damper.
[0019]
Since it is set as such a structure, in this seismic isolation structure, surface pressure can be given to a friction damper using the drawing-out force which acts between an upper structure and a lower structure.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing an outline of the configuration of a seismic isolation structure 10 according to an embodiment of the present invention.
As shown in the figure, the seismic isolation structure 10 is interposed between the lower structure 11 and the upper structure 12 of the building to insulate them, and is fixed to the lower structure 11 side. The lower flange 14, the upper flange 15 fixed to the upper structure 12 side, and the laminated rubber 16 disposed between the lower flange 14 and the upper flange 15 are configured.
[0021]
The lower flange 14, the upper flange 15 and the laminated rubber 16 are all formed in a substantially circular shape when viewed from above, and a through hole 18 is formed in the center thereof.
[0022]
The through-hole 18 is provided with a pull-out preventing member 20 for restricting the lower structure 11 and the upper structure 12 from separating in the vertical direction. Specifically, the pull-out prevention member 20 includes a substantially circular upper flange 21 and a lower flange 22 and a cylindrical member 23 that connects the upper flange 21 and the lower flange 22. Is inserted into the through hole 18, the upper flange 21 is in contact with the upper surface 15 a of the upper flange 15 from the upper side, and the lower flange 22 is in contact with the lower surface 14 a of the lower flange 14 from the lower side. Further, the pull-out preventing member 20 is formed of a steel material.
[0023]
Further, among the iron plates 25, 25,... Constituting the laminated rubber 16, the one located substantially at the center in the vertical direction is to keep the horizontal distance between the laminated rubber 16 and the pull-out preventing member 20 constant. It is formed as an interval holding member 26. The spacing member 26 has an inner edge portion 26a protruding from the through hole 18 and is formed so as to surround the cylindrical member 23, and is in contact with the pull-out preventing member 20 so as to be relatively displaceable in the vertical direction. It has a configuration.
[0024]
Next, the operation will be described.
The seismic isolation structure 10 configured as described above is deformed as shown in FIG. 2 during an earthquake. That is, during an earthquake, the upper structure 12 is displaced relative to the lower structure 11 in the horizontal direction, and the laminated rubber 16 is deformed so as to follow this relative displacement. The displacement is transmitted to the pull-out prevention member 20 via the spacing member 26, and thereby the pull-out prevention member 20 is displaced in the same direction as the deformation direction of the laminated rubber 16. At this time, since the deformation direction of the laminated rubber 16 and the displacement direction of the upper structure 12 when viewed from the lower structure 11 side coincide with each other, the pull-out preventing member 20 that is displaced in the same direction as the laminated rubber 16 and the upper structure Collision with the upper flange 15 fixed to 12 is avoided.
[0025]
Similarly, since the displacement direction of the lower structure 12 and the displacement direction of the pull-out preventing member 20 when viewed from the upper structure 11 side coincide with each other, the pull-out preventing member 20 and the lower flange 14 collide with each other. To avoid.
[0026]
Further, when the earthquake is strong and the upper structure 12 and the lower structure 11 are to be displaced so as to be separated from each other, this can be regulated by the pull-out preventing member 20. Furthermore, when the pulling force acting between the upper structure 12 and the lower structure 11 (the force acting in the vertical direction) exceeds a predetermined allowable pulling load, the pulling prevention member 20 is plastically deformed. Thus, it is possible to prevent the drawing resistance from being lost suddenly. Further, in this case, the pull-out preventing member 20 exerts an energy absorbing function by plastic deformation, thereby reducing the vibration response of the building. Further, when the pull-out preventing member 20 is plastically deformed in this way, since the relative movement in the vertical direction between the pull-out preventing member 20 and the interval holding member 26 is allowed, the deformation of the pull-out preventing member 20 holds the interval. There is no hindrance by the member 26, and conversely, no adverse effect is exerted on the laminated rubber 16 from the pull-out preventing member 20 via the spacing member 26.
[0027]
As described above, in the above-described seismic isolation structure 10, it is possible to counter the pulling force acting between the upper structure 12 and the lower structure 11 by the pull-out preventing member 20, and the laminated rubber by the spacing member 26. Since the pull-out preventing member 20 is displaced corresponding to the displacement of 16, the pull-out preventing member 20 is less likely to collide with the upper structure 12 and the lower structure 11, and safety is high. In this case, since the pull-out preventing member 20 does not hinder the horizontal restoring force characteristic of the laminated rubber 16, it is possible to ensure the performance as a seismic isolation structure while maintaining the resistance to the pull-out force. it can. Thereby, the seismic isolation structure 10 can be made suitable for a seismic isolation building in which a pulling force is generated in the event of a large earthquake, and the use of the seismic isolation structure can be expanded.
[0028]
In addition, since the upper flange 21 and the lower flange 22 of the pull-out preventing member 20 are configured to be in contact with the upper surface 15a side of the upper flange 15 and the lower surface 14a side of the lower flange 14, resistance performance against pull-out force is obtained. In addition, the seismic isolation structure 10 can be a simple mechanism, and can realize a structure with little secular change and requiring no maintenance.
[0029]
Further, the pull-out prevention member 20 is inserted into the through hole 18 formed in the laminated rubber 16, and part of the iron plates 25, 25,. Because of the contact, the seismic isolation structure 10 can be easily manufactured and transported as a unit, and installation work can be facilitated.
[0030]
Furthermore, since the pull-out prevention member 20 is formed of a steel material having plastic deformation capability, even if a pull-out force exceeding the allowable pull-out load is applied in the event of a large earthquake, it is possible to prevent the pull-out resistance from being suddenly lost and safety. Can be secured. In this case, the pull-out preventing member 20 can be plastically deformed so that it functions as a hysteresis damper, and a further excellent vibration response reduction effect can be obtained.
[0031]
In addition, since the spacing member 26 is in contact with the pull-out preventing member 20 so as to be relatively movable in the vertical direction, the plastic deformation of the pull-out preventing member 20 is not hindered. It is possible to avoid adverse effects on the laminated rubber 16 via the, and safety is high.
[0032]
In the above embodiment, other configurations may be adopted without departing from the spirit of the present invention.
For example, in the above embodiment, fluororesin or the like is provided between the lower surface of the upper flange 21 and the upper surface 15a of the upper flange 15 and between the upper surface of the lower flange 22 and the lower surface 14a of the lower flange 14 in the pull-out preventing member 20. When a pulling force is applied between the upper structure 12 and the lower structure 11, a surface pressure can be applied to these friction materials. These can be made to function as friction dampers by utilizing the horizontal slip that occurs between the upper flange 15 and the lower flange 14. In this case, it is possible to obtain a further excellent vibration response reduction effect by utilizing the damping force.
In this case, a stainless plate, a steel plate, a titanium plate, polytetrafluoroethylene, or the like may be used instead of the fluororesin.
[0033]
Furthermore, in the above embodiment, the laminated rubber 16 has a donut shape, but instead, a plurality of laminated rubbers may be arranged around the pull-out preventing member 20.
[0034]
In addition, various modifications can be made without departing from the spirit of the present invention, and it is needless to say that the above modification examples may be appropriately combined.
[0035]
【The invention's effect】
As described above, in the seismic isolation structure according to the first aspect, since the pull-out preventing member is displaced by the spacing member in accordance with the displacement of the laminated rubber, the pull-out preventing member includes the upper structure and the lower structure. There is little risk of collision with the machine and safety is high. In addition, since the pull-out prevention member does not collide with the upper structure or the lower structure and disturb the horizontal restoring force characteristic of the laminated rubber, the performance as a seismic isolation structure is secured while maintaining the resistance against the pull-out force. be able to. Therefore, it is possible to satisfactorily apply this seismic isolation structure to a seismic isolation building in which a pull-out force is generated in the event of a large earthquake, thereby expanding the applications of the seismic isolation structure.
In addition, if the pull-out prevention member is inserted into the through hole formed in the laminated rubber and a part of the plate constituting the laminated rubber is integrated with the spacing member, the seismic isolation structure is unitized. Manufacture, transportation, etc. can be performed easily, and installation work can be facilitated.
[0036]
In this case, if the pull-out prevention member is configured to contact the upper surface side of the upper flange and the lower surface side of the lower flange as in claim 2, a mechanism that resists the pull-out force can be formed with a simple structure. Therefore, it is possible to realize a device that has little secular change and does not require maintenance.
[0038]
Furthermore, if the pull-out prevention member is formed of a material having plastic deformation ability as in claim 3 , even if a pull-out force exceeding an allowable pull-out force acts during a large earthquake, the pull-out resistance is suddenly lost. It can prevent and secure safety. In this case, the pull-out preventing member can be made to function as a hysteresis damper to obtain a further excellent vibration response reduction effect.
[0039]
Further, in this case, as in claim 4 , if the spacing member is in contact with the pull-out preventing member so as to be relatively movable in the vertical direction, the plastic deformation of the pull-out preventing member is not hindered, Conversely, adverse effects on the laminated rubber can be avoided via the spacing member. Thus, the invention according to claim 3 can be realized satisfactorily.
[0040]
Furthermore, if a friction damper is formed between the pull-out prevention member and the lower surfaces of the upper flange and the lower flange as in claim 5 , a more excellent vibration response reduction effect can be obtained particularly during a large earthquake. Obtainable.
[Brief description of the drawings]
FIG. 1 is a vertical sectional view of a seismic isolation structure schematically showing an embodiment of the present invention.
FIG. 2 is an elevational sectional view showing a situation when the seismic isolation structure shown in FIG. 1 is deformed during an earthquake.
FIG. 3 is an elevational sectional view showing a configuration of a stopper that is conventionally provided between a base of a base-isolated building and an upper structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Base isolation structure 11 Lower structure 12 Upper structure 14 Lower flange 14a Lower surface 15 Upper flange 15a Upper surface 16 Laminated rubber 18 Through-hole 20 Pull-out prevention member 26 Space | interval holding member

Claims (5)

Between the lower structure and the upper structure of the building, a laminated rubber formed by laminating a plurality of plates and rubber is interposed,
Between the lower structure and the upper structure, there is provided a pull-out preventing member that restricts the relative displacement in the direction in which the lower and upper structures are separated and allows the relative displacement in the horizontal direction.
Between the pull-out prevention member and the laminated rubber, in a seismic isolation structure provided with a spacing member that keeps a horizontal distance between them constant ,
The laminated rubber, when viewed from above, has a through hole at the center thereof,
The pull-out prevention member is inserted into the through hole,
The seismic isolation structure , wherein the spacing member is integrated with a part of the plate constituting the laminated rubber .   The seismic isolation structure according to claim 1, wherein the laminated rubber is provided between a lower flange fixed to the lower structure side and an upper flange fixed to the upper structure side, and the pull-out preventing member is The seismic isolation structure is characterized in that the lower flange is in contact with the upper flange from the lower surface side and the upper flange is in contact with the upper flange from the upper surface side so as to be relatively displaceable in the horizontal direction. The seismic isolation structure according to claim 1 or 2 ,
The seismic isolation structure, wherein the pull-out preventing member is formed of a material that can be plastically deformed when a force greater than a predetermined force is applied in a separation direction of the upper structure and the lower structure. The seismic isolation structure according to claim 3 ,
The said isolation | separation prevention member and the said space | interval holding member are set as the structure which touches so that a relative displacement is possible to an up-down direction, The seismic isolation structure characterized by the above-mentioned. The seismic isolation structure according to any one of claims 2 to 4 ,
A seismic isolation structure in which at least one of the upper surface of the upper flange and the lower surface of the lower flange and the pull-out preventing member constitute a friction damper.

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