JPH11182618A - Shock absorbing structure for base isolation bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce cost by decreasing rigidity of base isolation bearing, and certainly prevent shock from occurring in base isolation bearing during horizontal motion. SOLUTION: In a base isolation bearing, a base isolation carrier 4 holding a ball 3 is provided on the structure 2 side, a receiving plate 5 whose upper surface 5a is formed so as to have almost conical slope with which the ball 3 of the base isolation carrier 4 comes into contact is provided on the formation side, and a stopper member 7 for restricting the base isolation carrier 4 from moving out of the receiving plate 5 is wall-shapedly stood on the peripheral end of the receiving plate 5. The receiving plate 5 can move horizontally, and sliding frictional force between the lower surface 5b and the upper surface of the foundation 1 during motion can mitigate shock.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shock-absorbing structure for a seismic isolation bearing which is interposed between a foundation and a structure and allows the structure to move horizontally with respect to the foundation.

[0002]

2. Description of the Related Art Seismic isolation bearings are used to protect buildings from vibrations caused by earthquakes or the like. Some seismic isolation bearings have rolling and sliding bodies in contact with a saucer with a mortar-shaped recess formed on the surface.For example, a large number of small-diameter balls are arranged around a large-diameter ball and held. A free bearing that supports rolling in the concave portion, a single ball rolling bearing that interposes a single ball between the upper support plate and the tray, or a single ball slides and rolls on the inner peripheral surface of the holding portion concave portion. There are sliding rolling bearings or sliding bearings in which a sliding body slides on a tray.

When arranging seismic isolation bearings between a foundation and a building, it is necessary to arrange four or more seismic isolation bearings even in a general house in consideration of the weight and balance. Occurs. Therefore, as shown in FIG. 5, a plurality of seismic isolation bearings a <b> 1 to a <b> 4 are provided in each part of the building b.

[0004]

Here, when a plurality of seismic isolation bearings a1 to a4 are disposed between the building b and the foundation, the balls c in the installed state in all the seismic isolation bearings a1 to a4 are used. Ideally is located exactly at the center of the tray d.

[0005] However, as shown in FIG. 5, it is assumed that the center of the ball c is shifted from the center of the tray d in a normal state in a part of the seismic isolation bearing (a1 in FIG. 5). That is, when the ball c moves in response to the movement of the building b due to the seismic motion, the displaced ball c is replaced by another seismic isolation bearing (a2 to a4 in FIG. 5) as shown by a two-dot chain line in the figure. It reaches the peripheral end of the tray d earlier than before. In the event that an over-designed earthquake arrives, the ball may move out of the saucer.

On the other hand, it is conceivable to provide a wall-shaped stopper member (unknown) for restricting the movement of the ball c to the outside at the peripheral end of each of the trays d. That is, as shown in FIG.
It is assumed that a part of mass m is supported. Assuming that the angle θ of the straight line connecting the contact point f and the ball c to the vertical line in the state where the ball c hits the stopper member e is 45 °, g is the gravitational acceleration, α is the acceleration at the time of the collision, and the stopper is based on the contact point f. Is smaller than the moment against it (mα · sin4
5 ° <mg · cos45 °), the ball does not climb over the stopper. That is, if α <g, the ball does not climb over the stopper.

However, in the above-described seismic isolation bearing, the center position of the ball and the tray are aligned with each other, but the center position is shifted by one seismic isolation bearing, for example. Then, the shifted ball may reach the peripheral end of the tray d before the other seismic isolation bearings, and the ball may hit the stopper member before the other ball. In this case, since the horizontal load (Mα) of the collision is concentrated on the ball hitting ahead, the ball can easily get over the stopper. In other words, the moment of trying to get over the stopper with the contact point f as the base point is Mα ·
The moment mg · co which becomes sin 45 ° and resists it
To make it smaller than s45 °, it is necessary to satisfy the condition of α <mg / M. That is, if all the balls collide at the same time, the acceleration over the stopper is very large, α> g, but if only one ball collides first, α> (m / M) · g, which is very small. . For example, when the 12 seismic isolation devices share the load evenly, the acceleration at the time of a collision that gets over becomes α> (1/12) g.

On the other hand, when arranging the seismic isolation bearings between the foundation and the building, to ensure that the center positions of the respective seismic isolation bearings are aligned, for example, the interval between the seismic isolation bearings is 10
(M) If there is an accuracy of 1 (cm) unit, 1/100
There is a problem in that zero precision alignment is required, and center alignment becomes extremely difficult.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is possible to ensure the effect of a stopper of a seismic isolation bearing and to reduce an impact generated at the time of a stopper collision. An object of the present invention is to provide a cushioning structure for a seismic bearing.

[0010]

The present invention has the following configuration to achieve the above object. The invention of claim 1 is
In a seismic isolation bearing that is interposed between a foundation and a structure to allow horizontal movement of the structure relative to the foundation, one of the foundation or the structure has a rolling or sliding body having a rolling or sliding body. And the other of the foundation or structure,
The seismic isolation support makes it possible to move the plate member in contact with the surface in the horizontal direction, and a peripheral end portion of the plate member is provided with a stopper member for restricting the seismic isolation support from moving outside the plate member. It is a buffer structure for seismic isolation bearings characterized by being erected. According to a second aspect of the present invention, the plate member is installed in contact with the foundation or structure, and when the seismic isolation support collides with the stopper member, the plate member moves and the impact force can be reduced by the frictional force during movement. The shock absorbing structure of the seismic isolation bearing according to claim 1, wherein the shock absorbing structure is configured as described above. The invention of claim 3 is
2. The apparatus according to claim 1, wherein movement limiting means for limiting movement of the installed dish member with respect to the foundation or the structure over a predetermined distance is provided between the dish member and the foundation or the structure.
Or the shock absorbing structure of the seismic isolation bearing described in 2. Claim 4
According to the invention, the movement restricting means accommodates the pin body fixed to one of the opposing portions of the dish member and the base or the structure and the pin body formed on the other so as to be movable by a fixed distance in the horizontal direction. The cushioning structure for a seismic isolation bearing according to claim 3, wherein the cushioning structure is a recess. The invention according to claim 5 is that, between the dish member side of the movement restricting means and the foundation or structure side,
5. A cushioning material is interposed therebetween.
The shock absorbing structure of the seismic isolation bearing described in (1).

Structures, such as buildings, are usually supported on a foundation by a plurality of seismic isolation bearings. If some (one or more) of the seismic isolation bearings are not aligned with the center of the support and the seismic isolation support, when the structure moves horizontally due to seismic motion, In some cases, only the seismic isolation bearing abuts the stopper member before the other seismic isolation bearings. In this case, the stopper member is pressed by a part of the seismic isolation support, causing an impact.

Therefore, according to the first aspect of the present invention, in a seismic isolation bearing having a seismic isolation support and a dish member, the dish member can be moved in a horizontal direction, and a stopper member is formed on a peripheral end of the dish member in a wall shape. When the plate member is installed, the plate member moves in the horizontal direction while generating a resistance to the pressing force when the seismic isolation support comes into contact with the stopper member. Therefore, even if the center positions of the seismic isolation bearings are not initially aligned, and even if the seismic isolation support hits the stopper member in some of the seismic isolation bearings, the plate member generates resistance in the seismic isolation support. It moves horizontally, and eventually a collision occurs in other seismic isolation bearings, and the horizontal impact force is distributed to each stopper member. Therefore, in each seismic isolation bearing, since the seismic isolation support contacts the stopper member, the pressing force due to the horizontal movement of the structure is dispersed, and the impact is reduced.

According to the second aspect of the present invention, the plate member is installed in contact with a foundation or a structure, and when the seismic isolation support collides with the stopper, the plate member moves to reduce the impact force of the plate member. It can be reduced by force. Therefore,
If the plate member is installed so that the friction coefficient due to the movement of the plate member is 1 or less, the plate member will move when a horizontal force greater than the load mg applied to the seismic isolation support acts, and the impact force of the collision will be reduced. The frictional force required for the movement of the member is reduced to μmg. Further, in the invention of claim 3, a movement restricting means is provided for restricting movement of the dish member over a certain distance. That is, if the plate member moves arbitrarily with respect to the foundation due to the impact, the distance between the plate members may deviate from the design by more than an allowable value. The deviation from the value can be reliably prevented. Further, in the invention of claim 4, the movement restricting means includes:
Since one is a pin and the other is a recess, the movement restricting means can be configured with a simple configuration. Further, since the pin body and the concave portion are fixed to opposing portions of the dish member and the foundation or structure, they are covered by the dish member and hidden from the outside. Further, it is possible to eliminate the mounting bracket for the plate member.
Further, in the invention of claim 5, since the cushioning material is interposed between the dish member side of the movement restricting means and the foundation or structure side, the dish member is moved slowly as it moves, and the seismic isolation is performed. When the support presses the stopper member, a resistance force against the pressing force can be reliably generated.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows Embodiment 1 of the present invention.
FIG. 2 is a schematic view of a state in which a stopper member 7 is provided on a tray 5.

As shown in FIG. 1, the seismic isolation bearing according to the embodiment is provided with a plurality of intervening members between a foundation 1 and a structure 2 such as a building in a horizontal direction relative to the foundation 1. A seismic isolation support 4 holding a ball (an example of a rolling body) 3 is provided on the structure 2 side, and
Is provided with a saucer (an example of a dish member) 5 having an upper surface 5a formed so that the ball 3 of the seismic isolation support 4 has a substantially mortar-shaped slope in contact with the surface thereof.

The seismic isolation support 4 has a concave portion 6a formed at the bottom of a retainer 6 for holding the ball 3, and the ball 3 slides and rolls on a spherical portion on the inner peripheral upper surface of the concave portion 6a.

The receiving tray 5 has an upper surface 5a of a substantially disk shape having a circular shape in plan view formed on a substantially linearly inclined slope. At the peripheral end of the tray 5, a stopper member 7 for restricting the seismic isolation support 4 from moving to the outside of the tray 5 is provided upright in a wall shape.

The receiving tray 5 is movable in the horizontal direction, and a frictional force of μmg is generated with respect to the movement (preferable friction coefficient μ <1). That is, the tray 5
The lower surface 5b is a flat surface, and the lower surface 5b is placed in contact with the flat surface of the foundation 1 or on an iron plate thereon, so that a sliding frictional force is generated when the lower surface 5b and the upper surface of the foundation 1 move. I do.

In the embodiment, a mounting bracket 8 is fastened to the foundation 1 by bolts 9 so as to surround the outer periphery of the stopper member 7 of the tray 5 from outside. However, this fastening force is determined in consideration of the positioning when the tray 5 is installed and the movement by the wind. Moreover, as shown in FIG.
The through hole 10 is formed in a circular hole (L2) having an inner diameter larger than the outer diameter (L1) of the shaft portion 9a of the bolt.

As described above, since the bolt 9 is loosely passed through the through hole 10, when the receiving tray 5 in the installed state moves with respect to the foundation 1, the mounting bracket 8 also moves. As a configuration of the movement restricting means, the through hole 10 is formed to have a fixed size (L2) larger than the bolt shaft outer diameter (L1) as described above, so that the mounting bracket 8 can be moved, and When the bolt shaft 9a hits the inner wall of the through hole 10, the tray 5 is restricted from moving more than a certain distance with respect to the foundation 1.

The cushioning structure of the seismic isolation bearing according to the first embodiment will be described. First, a structure 2 such as a building is supported on a foundation 1 by a plurality of seismic isolation bearings. For example, as shown in FIG. 5 described above, when a part (one or more) of the plurality of seismic isolation bearings is not aligned with the center position of the tray 5 and the seismic isolation support 4, the structure is caused by the seismic motion. When the object 2 moves horizontally, only some of the seismic isolation bearings have the stopper member 7 (the ball 3 in the figure) before the other seismic isolation bearings.
In this case, the stopper member 7 is pressed by a part of the seismic isolation support 4.

In the seismic isolation bearing according to the first embodiment, the tray 5 is mounted on the foundation 1 so that the tray 5 can be moved in the horizontal direction and a frictional resistance is generated against the movement.
Is formed such that the receiving tray 5 is allowed to move and the through hole 8a is formed to have an inner diameter larger than the outer diameter of the bolt shaft 9a.
For this reason, as shown by the two-dot chain line in FIG. 1, while the tray 5 generates a resistance to the pressing force when the seismic isolation support 4 abuts on the stopper member 7, Move horizontally.

Therefore, even if the center positions of the seismic isolation bearings are not initially aligned, even if the seismic isolation support 4 (the ball 3 or the like) and the stopper member 5 hit against one of the seismic isolation supports, In the seismic bearing, the tray 5 moves horizontally with resistance, and eventually a collision occurs in other seismic isolation bearings.
The horizontal impact force is distributed to each stopper member 7. Therefore,
In each seismic isolation support, the seismic isolation support 4 abuts against the stopper member 7, so that the pressing force due to the horizontal movement of the structure 2 is dispersed, and the impact is reduced.

Further, since the receiving tray 5 is mounted in contact with the foundation 1 so as to be movable in the horizontal direction and to generate a frictional force of μmg upon the movement, the seismic isolation support collides with the stopper. Sometimes, when the plate member moves, the impact force can be reduced by the friction force at the time of movement.

Further, there is provided a movement restricting means for restricting the movement of the receiving tray 5 by a certain distance by the bolt shaft 9a and the through hole 10. By this movement restricting means, a deviation from a design allowable value can be surely prevented.

Next, a seismic isolation bearing according to the second embodiment will be described with reference to FIGS. Embodiment 1
The same parts as those described above are denoted by the same reference numerals and description thereof will be omitted. As shown in FIG. 3, the seismic isolation bearing according to Embodiment 2 serves as a movement restricting unit that restricts the movement of the receiving tray 5 in the installed state with respect to the foundation 1 by a certain distance or more. A bar-shaped pin body 11 having a short length and an outer diameter L3 is planted on the side of the foundation 1 at the opposing portion, and the pin body 11 is accommodated in the lower surface of the tray 5 so as to be movable by a fixed distance in the horizontal direction. A recess 12 having a lateral length L4 is formed.

As shown in detail in FIG. 4, a cushioning material (for example, an elastic material or a high-damping plastic material such as lead) is provided between the recess 12 on the tray 5 side of the movement restricting means and the pin body 11 on the base side. A deformable material 13 is interposed.

According to the second embodiment, in addition to the operation and effect of the first embodiment, the movement restricting means is constituted by one of the pin body 11 and the other by the concave portion 12, so that the movement restricting means can be constituted with a simple structure. Also, since the pin body 11 and the concave portion 12 are fixed to mutually opposing portions of the tray 5 and the base 1, the tray 5
From the outside and hide from the outside. Further, it is not necessary to use the mounting bracket 8 of the receiving tray 5, and the configuration is simplified.

Further, the concave portion 1 on the tray 5 side of the movement restricting means.
Since the cushioning material 13 is interposed between the base member 2 and the pin body 11 on the base side, the moving force is attenuated by the sliding friction as described above when the tray moves on the base due to the collision. It can move more slowly with the material 13 damped,
Not only can the seismic isolation support 4 reliably generate a resistance force against the pressing force when the stopper member 7 is pressed, but also can have a damping force characteristic that cannot be set only by the sliding friction force.

Although the preferred embodiment of the present invention has been described in the above embodiment, it is needless to say that the present invention is not limited to this. In the first and second embodiments, the sliding bearing is described as an example of the seismic isolation bearing. However, the seismic isolation bearing of the present invention is not limited to this. In addition, a free bearing, a single-ball rolling bearing, or a sliding bearing is used. But it is an implementation range.

In the first and second embodiments, the receiving tray is provided on the base side and the seismic isolation support is provided on the structure side. In the first embodiment, the receiving tray 5 is installed with the mounting bracket 8 attached. However, in the present invention, the mounting bracket may or may not be mounted. Further, as in the second embodiment, the movement restricting means is provided on the receiving side of the concave portion on the base side with the pin body, but the present invention is not limited to this configuration. It may be provided.

[0032]

As described above, according to the first aspect of the invention, since the seismic isolation support comes into contact with the stopper member in each seismic isolation bearing, the pressing force due to the horizontal movement of the structure is dispersed, and the impact is reduced. Is done. According to the second aspect of the present invention, if the friction coefficient μ due to the movement of the plate member is set so as to be 1 or less, μ is applied to the load mg applied to the seismic isolation support.
When the horizontal force of mg or more acts, the plate member moves, and the impact force of the collision is the friction force μ required for the movement of the plate member.
mg and can be reduced. According to the third aspect of the present invention, since the movement restricting means for restricting the movement of the plate member by a predetermined distance or more is provided, it is possible to reliably prevent the distance between the plate members from being deviated from the design allowable value. Claim 4
According to the invention, since one is a pin body and the other is a recess, the movement restricting means can be configured with a simple configuration. Further, since the pin body and the concave portion are fixed to opposing portions of the dish member and the foundation or structure, they are covered by the dish member and hidden from the outside. Further, it is not necessary to use a mounting member for the dish member. According to the invention of claim 5, between the dish member side of the movement restricting means and the foundation or structure side,
Since the cushioning material is interposed, the impact when the dish member moves is reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a cushioning structure of a seismic isolation bearing according to Embodiment 1 of the present invention.

FIG. 2 is a detailed view of a tray and a stopper member of the seismic isolation bearing.

FIG. 3 is an explanatory view of a cushioning structure of a seismic isolation bearing according to a second embodiment.

FIG. 4 is a detailed sectional view of a pin body and a concave portion according to an example of the movement restricting means.

FIG. 5 is a state diagram in which a plurality of seismic isolation bearings are interposed between a structure such as a building and a foundation.

FIG. 6 is an explanatory view of contact of a ball with a stopper member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Foundation 2 Structure 3 Ball 4 Seismic isolation support 5 Receiving tray 7 Stopper member 8 Mounting bracket 10 Through hole 11 Pin body 12 Recess

Claims (5)

[Claims] 1. A seismic isolation bearing that intervenes between a foundation and a structure to allow horizontal movement of the structure relative to the foundation, wherein one of the foundation and the structure has a rolling or sliding body. A seismic isolation support having a seismic isolation support on the other side of the foundation or structure, wherein the seismic isolation support makes a plate member in contact with the surface thereof movable in the horizontal direction; A shock-absorbing structure for a seismic isolation bearing, wherein a stopper member for restricting movement of a support body to the outside of a plate member is provided upright in a wall shape. 2. The dish member is installed in contact with a foundation or a structure. When the seismic isolation support collides with the stopper member, the dish member moves so that the impact force can be reduced by the friction force at the time of movement. The cushioning structure for a seismic isolation bearing according to claim 1, wherein: 3. The apparatus according to claim 1, wherein a movement restricting means for restricting movement of the installed dish member with respect to the foundation or the structure over a predetermined distance is provided between the dish member and the foundation or the structure. 3. The cushioning structure of the seismic isolation bearing according to 1 or 2. 4. The movement restricting means accommodates a pin body fixed to one of opposing portions of the dish member and the foundation or structure and a pin body formed on the other so as to be movable by a predetermined distance in the horizontal direction. The cushioning structure for a seismic isolation bearing according to claim 3, further comprising: 5. The cushioning structure for a seismic isolation bearing according to claim 3, wherein a cushioning material is interposed between the dish member side of the movement restricting means and the foundation or structure side.