JPH112046A - Device to prevent lifting of seismic isolation structure - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve the durability of laminated rubber by preventing the upper structure from rising from the lower structure and to prevent tensile force from being applied to the laminated rubber, and to improve seismic isolation. Provided is a device for preventing a seismic isolation structure from rising, which reduces the design constraints of the structure. SOLUTION: First and second steel members 9 and 10 are respectively provided on surfaces of an upper structure 5 and a lower structure 3 facing each other. Furthermore, the first steel member 9 is
Projection 11 provided to project downward from upper structure 5
And an extending portion 12 provided so as to extend to the side from the protruding portion 11, and the second steel member 10
When the upper structure 5 is displaced upward, a stopper portion 16 is formed which comes into contact with the extended portion of the first steel member 9 and regulates the upward displacement of the second steel member 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation structure in which an upper structure is supported on a lower structure via a laminated rubber, in order to prevent the upper structure from rising from the lower structure. And a lift prevention device.

[0002]

2. Description of the Related Art As is well known, in recent years, seismic isolation structures have been realized in which an upper structure is supported on a lower structure via a laminated rubber, thereby increasing a natural period to obtain a seismic isolation effect. I have. As a laminated rubber used for a seismic isolation structure, a laminated steel sheet and a rubber sheet that are alternately stacked and bonded are most commonly used. Such laminated rubber is
For compressive force, both strength and rigidity are very large, but for tensile force, cracks and voids occur in rubber,
Both stiffness is significantly reduced. For this reason, at present, seismic isolation structures are designed so as not to generate a tensile force in the laminated rubber.

[0003]

As described above, the seismic isolation structure needs to be designed so as not to generate a tensile force in the laminated rubber. As a result, the aspect ratio (tower ratio) of the structure is also 3 The upper limit was about 3.5. In recent years, however, attention has been paid to the safety of seismically isolated buildings during earthquakes, which has led to the need to seismically isolate super-high-rise buildings and buildings with very large aspect ratios that have been out of scope. Is growing.

The present invention has been made in view of the above circumstances, and prevents the upper structure from being lifted from the lower structure and prevents tensile force from being applied to the laminated rubber, thereby improving the durability of the laminated rubber. It is an object of the present invention to provide a device for preventing the seismic isolation structure from rising, which improves the design and reduces the design constraints of the seismic isolation structure.

[0005]

Means for Solving the Problems To solve the above problems, the present invention employs the following means. That is,
The device for preventing lifting of a base-isolated structure according to claim 1 is a device for preventing lifting of a base-isolated structure comprising a lower structure and an upper structure supported on the lower structure via a laminated rubber. And a first and a second steel member respectively provided on opposing surfaces of the upper structure and the lower structure, wherein one of the first and second steel members is A projecting portion provided in a vertically protruding state from the structure or the lower structure, and an extending portion provided to extend laterally from the projecting portion. When the upper structure is displaced upward, a stopper portion is formed which comes into contact with the one extension portion and regulates the one vertical displacement.

A second aspect of the present invention is a device for preventing a seismic isolation structure from rising, wherein the first steel member has a protruding portion. It is formed in a column or a cylinder, and its extension is formed by a flange-shaped steel plate provided at the tip of the projection, and the second steel member projects upward from the lower structure. The steel tube is provided with a steel pipe provided in a state, and the stopper portion has an insertion hole through which the protrusion of the first steel member is inserted, and is made of a steel plate horizontally installed inside the steel pipe. It is characterized by the following.

According to the device for preventing the seismic isolation structure from lifting, the above structure can be used to prevent the upper structure from rising from the lower structure during an earthquake.

According to a third aspect of the present invention, there is provided a device for preventing a seismic isolation structure from rising, wherein the first steel member includes an extending portion and the first portion. On at least one of the opposing surfaces of the stopper portion of the second steel member, when the extension portion and the stopper portion abut each other and are relatively displaced in the horizontal direction, the extension portion and the stopper portion A sliding member is provided for reducing frictional force generated therebetween.

[0009] The device for preventing the seismic isolation structure from lifting up includes:
In the event of an earthquake, the upper structure prevents the upper structure from rising from the lower structure, and acts so as not to hinder relative displacement of the upper structure and the lower structure in the horizontal direction due to the horizontal deformation of the laminated rubber.

According to a fourth aspect of the present invention, there is provided a device for preventing a seismic isolation structure from rising, wherein the first steel member has a protruding portion. A cushioning material is provided on a portion facing the insertion hole to absorb an impact when the protrusion and the inner periphery of the insertion hole collide.

[0011] Because of the above-mentioned configuration, in the device for preventing the seismic isolation structure from lifting, the first and second steel members are less likely to be damaged during an earthquake.

[0012]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows an example in which the lifting prevention device 2 according to the present invention is applied to the seismic isolation structure 1. As shown in the figure, the seismic isolation structure 1
It comprises a lower structure 3 and an upper structure 5 supported on the lower structure 3 via a laminated rubber 4. Further, the lifting prevention device 2 is interposed between the lower structure 3 and the upper structure 5 and is installed at another position close to the laminated rubber 4.

FIG. 1 is an enlarged view showing the situation in the vicinity of the lifting prevention device 2 in FIG. As shown in the figure, the lifting prevention device 2 is provided with a foundation beam 7 of the upper structure 5.
And a second steel member 10 installed on a support base 8 provided in the lower structure 3.

The first steel member 9 includes a protruding portion 11 formed of a steel pipe protruding downward from the foundation beam 7 and an extension portion formed of a flange-shaped steel plate provided at the tip of the protruding portion 11. 1
2 is provided.

On the other hand, the second steel member 10 is provided with a support portion 14 provided on the support base 8, a steel pipe 15 provided on the support portion 14 so as to protrude upward, and a second steel member 10 provided in the steel pipe 15. And a stopper portion 16 made of a steel plate.

The stopper 16 has an insertion hole 17 near the center thereof for inserting the projection 11 of the first steel member 9.
It is formed as. A cushioning member 18 made of a material such as natural rubber, synthetic rubber, hard urethane, or plastic is disposed at a portion of the outer periphery of the protruding portion 11 opposite to the insertion hole 17.

Further, the surface of the first steel member 9 on the side facing the stopper portion 16 of the extension portion 12 is provided when the extension portion 12 and the stopper portion 16 come into contact with each other. A sliding member 19 for reducing a horizontal friction force generated in the sliding member 19 is disposed. This sliding material 19 is, for example,
It is formed of a material such as a tetrafluoroethylene resin or a stainless steel plate, or a ball roller bearing. The distance between the extension 12 and the stopper 16 is set equal to the amount of deformation of the rubber portion of the laminated rubber 4 due to the weight of the upper structure 5.

The above is the main configuration of the present embodiment. Next, the operation and effects of the lifting prevention device 2 will be described. When an earthquake occurs, vibration tends to be transmitted from the lower structure 3 to the upper structure 5, but with respect to horizontal vibration, the laminated rubber 4 deforms in the horizontal direction, so that the upper structure 5 is transferred to the lower structure 3. It acts to allow relative displacement in the horizontal direction. Therefore, the horizontal vibration energy from the lower structure 3 is not directly transmitted to the upper structure 5, whereby the safety of the upper structure 5 against horizontal vibration is maintained. Furthermore, when a vertical vibration occurs due to the earthquake, the downward displacement of the upper structure 5 hardly occurs because it is regulated by the laminated rubber 4, while the upward displacement of the upper structure 5 is When the stopper portion 16 and the extending portion 12 are in contact with each other, only the distance between the stopper portion 16 and the extending portion 12 is generated. That is, even when the upper structure 5 is displaced upward, no tensile force acts on the laminated rubber 4.

As described above, when the lifting prevention device 2 is applied to the seismic isolation structure 1, the lower structure 3 of the upper structure 5
Is prevented from being excessively lifted, thereby preventing a tensile force from acting on the laminated rubber 4. Therefore, cracks and voids do not occur in the laminated rubber 4 due to the earthquake, and the durability of the laminated rubber 4 can be improved, and the safety of the seismic isolation structure 1 during and after an earthquake can be protected. This also eliminates the need for the seismic isolation structure 1 to be designed so that no tensile force acts on the laminated rubber 4.
The degree of freedom in designing the seismic isolation structure 1 is improved as compared with the conventional case. This also makes it possible to freely set the aspect ratio (tower ratio) of the seismic isolation structure 1 as compared with the related art.

Further, in the present embodiment, the sliding member 19 is arranged on the surface of the stopper portion 16 on the side facing the extending portion 12. Therefore, even when the upper structure 5 rises from the lower structure 3 during the earthquake and the stopper portion 16 and the extension portion 12 come into contact with each other, the frictional force generated between the stopper portion 16 and the extension portion 12 causes the upper structure 5 to lose its friction. 5 does not hinder the relative displacement of the lower structure 3 with respect to the lower structure 3, whereby the seismic isolation structure 1
The function can be exhibited well.

Further, in the present embodiment, since the cushioning material 18 is provided at a portion of the outer periphery of the protruding portion 11 facing the insertion hole 17, the shock absorber 18 is provided between the upper structure 5 and the lower structure 3 in the horizontal direction during an earthquake. Relative displacement occurs, resulting in protrusions 11
Even when the inner and inner peripheries of the insertion hole 17 collide, it is possible to reduce the fear that the first and second steel members 9 and 10 may be broken.

In the above embodiment, other structures may be employed for the structure of each part of the seismic isolation structure 1 or the lifting prevention device 2 without departing from the gist of the present invention.

[0023]

As described above, according to the device for preventing the seismic isolation structure from lifting according to the present invention, the first and second vibrations are applied when the vertical vibration acts on the seismic isolation structure during an earthquake. By contacting the protrusion provided on one of the steel members with the stopper provided on the other,
The upper structure is prevented from rising from the lower structure. Therefore, the tensile force is prevented from acting on the laminated rubber of the seismic isolation structure during an earthquake, thereby improving the durability of the laminated rubber and protecting the seismic isolation structure during and after the earthquake. It will be. Further, it is not necessary to design the seismic isolation structure so that tensile force does not act on the laminated rubber, so that the degree of freedom in designing the seismic isolation structure can be improved as compared with the related art. This also makes it possible to freely set the aspect ratio (tower ratio) of the seismic isolation structure as compared with the related art. Further, the projecting portion of the first steel member of the device for preventing lifting of a seismic isolation structure of the present invention is formed in a cylindrical or cylindrical shape, and the extending portion is formed by a flange-shaped steel plate, while the second steel member is The present invention is simplified when the member is formed by a steel pipe and a steel plate having an insertion hole provided inside the steel pipe, and furthermore, the protrusion of the first steel member is inserted through the insertion hole. The configuration can be implemented well. In the device for preventing the seismic isolation structure from rising according to the present invention, a sliding member is provided on at least one of the opposing surfaces of the extending portion of the first steel member and the stopper portion of the second steel member. For example, even when the extension and the stopper come into contact with each other, the friction generated between the extension and the stopper can be reduced so that the seismic isolation structure can properly perform its function. it can. Further, in the device for preventing the seismic isolation structure from rising according to the present invention, if a cushioning material is provided on a portion of the outer periphery of the protrusion of the second steel member opposite to the insertion hole, the protrusion and the insertion hole may be provided. Even when the inner periphery collides, the safety of the device can be ensured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a lift prevention device schematically illustrating an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a part of the seismic isolation structure to which the uplift prevention device shown in FIG. 1 is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Seismic isolation structure 2 Lift prevention device 3 Lower structure 4 Laminated rubber 5 Upper structure 9 First steel member 10 Second steel member 11 Projection portion 12 Extension portion 14 Support portion 15 Steel pipe 16 Stopper portion 17 Insertion hole 18 cushioning material 19 sliding material

Claims (4)

[Claims] 1. An anti-lift device installed on a seismic isolation structure comprising a lower structure and an upper structure supported on the lower structure via a laminated rubber, wherein the upper structure and the lower structure are separated from each other. It comprises first and second steel members provided on opposing surfaces, respectively, and one of the first and second steel members protrudes vertically from the upper structure or the lower structure. And a projecting portion provided to extend laterally from the projecting portion, and the other, when the upper structure is displaced upward,
A device for preventing a seismic isolation structure from rising, wherein a stopper portion is formed to contact the one extension portion and regulate the one vertical displacement. 2. The device for preventing a seismic isolation structure from lifting according to claim 1, wherein the first steel member has a protruding portion formed in a cylindrical or cylindrical shape, and an extending portion thereof. The second steel member is formed by a flange-shaped steel plate provided at a tip of the protruding portion, and the second steel member is provided with a steel pipe provided to protrude upward from the lower structure. A lift prevention device for a seismic isolation structure, characterized in that the stopper portion has an insertion hole through which the projecting portion of the first steel member is inserted, and is made of a steel plate horizontally installed inside the steel pipe. 3. The device for preventing a seismic isolation structure from lifting according to claim 1, wherein the extension portion of the first steel member and the stopper portion of the second steel member face each other. At least one of the sliding members is provided with a sliding member for reducing a frictional force generated between the extending portion and the stopper portion when the extending portion and the stopper portion are in contact with each other and relatively displaced in the horizontal direction. A device for preventing a seismic isolation structure from being lifted. 4. The structure for preventing the seismic isolation structure from lifting according to claim 2, wherein a portion of the outer periphery of the protrusion of the first steel member facing the insertion hole has the protrusion. A cushioning material is provided for absorbing a shock when a collision occurs between the shock absorber and the inner periphery of the insertion hole.