JPH11315885A - Base isolation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To let highly excellent base isolation function be fulfilled when an earthquake occurs without increasing the frictional resistance of a rolling element with its damping coefficient made high, and concurrently, let the occurrence of micro vibration and rocking due to a wind be usually restrained. SOLUTION: At least either one surface of the upper or the lower opposite surface of a receiving stand 1 on the structural body A side and a receiving stand 2 on the basement B side is formed into each cycloid curved surface 1a and 2a, a spherical body 3 made of steel is held and disposed between the cycloid curved surfaces 1a and 2a so as to enable the receiving stand 2 on the structural body A side to be pivoted in such a way as to be slipped or rolled and moved in the horizontal direction with respect to the receiving stand 1 on the basement B side by way of the spherical body 3. Damping elements 4 formed out of visco-elastic bodies while being formed into a laminated shape or a spherical shape each, are interposed between the receiving stands 1 and 2 separately from the spherical body 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation device applied to a detached house or the like, and more particularly to a seismic isolation device capable of sliding or rolling a superstructure horizontally on a foundation via rolling elements such as steel balls. It relates to the seismic isolation device that is supported.

[0002]

2. Description of the Related Art Conventionally, as described in Japanese Patent Application Laid-Open No. 9-4279, this type of seismic isolation device has a structure in which the opposing surfaces of the pedestal on the upper structure side and the foundation side are each provided with a bottom point at the center. The sliding or rolling surface is formed into a parabolic shape by interposing a rolling element between the opposing surfaces of the parabolic shapes of these receiving stands, or a parabolic shape is described in JP-A-9-184542. A plurality of rolling elements such as steel balls are placed on a fixed pan on the foundation side, and a presser plate arranged on the lower surface of the upper structure side is brought into contact with these rolling elements to make the sliding or rolling surface flat. And others have been proposed.

[0003]

However, in the conventional seismic isolation device as described above, in order to enhance the seismic isolation performance, for example, the damping coefficient of a damping element constituting a slipping or rolling device, such as a sliding or rolling surface of a rolling element. When is increased, the frictional resistance of rolling elements such as steel balls increases, and stable vibration damping performance cannot be exhibited. Also, if the damping coefficient of the damping element is reduced, micro-vibration is likely to occur,
It was not suitable as a seismic isolation device for light-weight structures such as detached houses because it easily responded to wind.

[0004] The present invention has been made in view of the above circumstances, and it is possible to increase the damping coefficient without increasing the frictional resistance of the rolling elements, and to exhibit extremely excellent seismic isolation performance in the event of an earthquake. It is an object of the present invention to provide a seismic isolation device which is capable of suppressing generation of micro-vibration and wind due to wind, and which is very suitable for a detached house.

[0005]

According to a first aspect of the present invention, there is provided a seismic isolation device according to the first aspect of the present invention, wherein a rolling element is provided between a pedestal on a structure side and a pedestal on a foundation side. In the seismic isolation device, the pedestal on the structure side is supported so as to be able to slide or roll in the horizontal direction with respect to the pedestal on the foundation side by interposing the pedestal. It is characterized in that a damping element is interposed.

That is, according to the first aspect of the present invention, a slipping element made of a viscoelastic body is interposed between the pedestal on the structure side and the pedestal on the foundation side, separately from the rolling element. Alternatively, it is possible to increase the damping coefficient without increasing the frictional resistance of the rolling elements constituting the rolling device, thereby suppressing the occurrence of micro-vibration and the swaying due to the wind, and the occurrence of an earthquake. The horizontal movement at the time can be greatly attenuated to improve the vibration damping performance.

[0007] Here, the damping element may include:
As described in the above, even if it is constituted by a laminated viscoelastic body obtained by alternately laminating a plate-shaped viscoelastic body and a metal plate, it is formed in a spherical shape as described in claim 3 It may be composed of a viscoelastic body. According to a fourth aspect of the present invention, the contact surface between at least one of the pedestal on the structure side and the pedestal on the foundation side, which is in contact with the rolling element, is a cycloid curved surface, a flat surface, a parabolic surface or an arc. It is preferably formed on the surface.

In the above-mentioned damping element comprising a laminated viscoelastic body, a sliding or rolling mechanism is added to a contact surface of the damping element with a pedestal on the structure side. By doing so, the spring constant can be reduced and the vibration control performance at the time of an earthquake can be further enhanced.

Further, in the above-mentioned damping element comprising a spherical viscoelastic body, the contact surface of at least one of the two pedestals with which the damping element comes into contact is formed. By forming the damping element on a curved surface that allows sliding or rolling within a certain range, the damping coefficient changes according to the amount of elastic deformation of the spherical viscoelastic body according to the amount of movement in the horizontal direction, and the damping coefficient is adjusted to the amplitude. Vibration performance can be exhibited.

[0010] Further, the damping element composed of the viscoelastic body may be provided with a damping element made of the viscoelastic body, which slides or rolls in the horizontal direction on the base side pedestal. By arranging a stopper that also limits the movement range, a damping element for increasing the damping coefficient is used as a stopper for restricting horizontal sliding or rolling movement, thereby making the whole apparatus simple and compact. be able to.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram showing a basic configuration of a seismic isolation device according to a first embodiment of the present invention,
Interposing a steel sphere 3 as a rolling element between a cradle 1 fixed to the structure A side such as a column for a detached house and a cradle 2 fixed to the foundation B side such as a foundation for a detached house. Thereby, the receiving table 1 on the side of the structure A is supported so as to slide or roll in the horizontal direction with respect to the receiving table 2 on the foundation B side.

The contact surface 1a of the cradle 1 on the side of the structure A with the steel sphere 3 and the contact surface 2a of the cradle 2 on the side of the base B with the steel sphere 3 are both dish-shaped and centered. The steel ball 3 is sandwiched from above and below between the cycloid curved surfaces 1a, 2a facing each other in the two cradles 1, 2, and the spherical member 3 is formed in a horizontal plane. Is configured to be able to slide or roll on the cycloid curved surfaces 1a, 2a.

A plate-shaped viscoelastic body 4a is provided between the pedestal 1 on the structural body A side and the pedestal 2 on the base B side on both sides in the sliding or rolling direction of the pedestals 1, 2. Metal plate 4
and damping elements 4 and 4 composed of a laminated type viscoelastic body obtained by alternately laminating b. Although not shown in FIG. 1, a coil spring, a lamination, etc., for restoring the cradle 1 on the side of the structure A to a neutral position in a horizontal sliding or rolling movement range are provided on the cradles 1 and 2. One restoration element selected from rubber and a rubber-like elastic body is interposed.

In the seismic isolation device configured as described above, when a large vibration occurs in the horizontal direction due to the occurrence of an earthquake, the steel pedestal 1 on the structure A side and the steel pedestal 2 on the foundation B side are made of steel. By allowing horizontal relative sliding or rolling movement through the spherical body 3, a large horizontal load is prevented from acting on the structure A, and the structure A side and the foundation B are prevented from acting.
The horizontal vibration on the side can be attenuated by the damping elements 4 and 4 to exert a large seismic isolation function.

FIG. 2 is a conceptual diagram showing a basic configuration of a seismic isolation device according to a second embodiment of the present invention. The seismic isolation device shown in FIG. The contact surface 1a of the pedestal 1 with the steel sphere 3 and the contact surface 2a of the pedestal 2 on the base B side with the steel sphere 3
Are both formed as parabolic curved surfaces, and the damping elements 4, 4 composed of a laminated viscoelastic body are formed with upper and lower curved surfaces 4A,
4A, sliding support with stoppers is applied to both receiving stands 1 and 2 and the other configuration is the same as that of FIG. 1. Omitted.

FIG. 3 is a conceptual diagram showing a basic structure of a seismic isolation device according to a third embodiment of the present invention. The seismic isolation device shown in FIG. The contact surface 1a of the pedestal 1 with the steel sphere 3 and the contact surface 2a of the pedestal 2 on the base B side with the steel sphere 3
And a sliding mechanism 5 using a small-diameter steel sphere 5a at the contact point of the damping elements 4 and 4 composed of the laminated viscoelastic body with the pedestal 1 on the structure A side. Since other configurations are the same as those in FIG. 1, corresponding portions are denoted by the same reference numerals and description thereof is omitted.

In the seismic isolation devices of the second and third embodiments described above, a rolling or sliding function is added to the damping element 4 having a large damping coefficient to reduce the spring constant, so that an earthquake occurs. The vibration damping performance at the time can be further enhanced.

FIGS. 4 and 5 are a conceptual diagram and a plan view showing a basic configuration of a seismic isolation device according to a fourth embodiment of the present invention, and a plan view thereof, which is fixed to a structure A side such as a column for a detached house. A steel sphere 3 as a rolling element is interposed between the cradle 1 and a cradle 2 fixed to the foundation B side such as a base for a detached house. It is mounted so that it can slide or roll. The contact surfaces 1a and 2a of the pedestal 1 on the structure A side and the pedestal 2 on the foundation B side with the steel spheres 3 are both formed as cycloidal curved surfaces, and the cycloidal curves opposing each other above and below are formed. The steel sphere 3 is sandwiched between the surfaces 1a and 2a from above and below, and the sphere 3 is configured to slide or roll on the cycloid curved surfaces 1a and 2a in a horizontal plane.

Between the cradle 1 on the structural body A side and the cradle 2 on the foundation B side, a spherically formed viscous material is formed around the sliding or rolling movement of the cradles 1 and 2. A damping element 4 composed of an elastic body 4c and a coil spring 6 for restoring to the center position of the sliding or rolling movement range are alternately arranged at intervals in the circumferential direction. These spherical viscoelastic bodies 4
The contact surfaces 1b and 2b of the receiving tables 1 and 2 with which the damping element 4 made of C comes into contact are also formed as cycloid curved surfaces that allow the damping element 4 to slide or roll within a certain range.

FIGS. 6 and 7 are a conceptual diagram and a plan view showing a basic configuration of a seismic isolation device according to a fifth embodiment of the present invention, and a plan view thereof. In the fifth embodiment, a structure A side is shown. At the center position between the pedestal 1 and the pedestal 2 on the side of the base B, the damping element 4 composed of the spherical viscoelastic body 4c is arranged while being sandwiched by the vertically opposed cycloidal curved surfaces 1b and 2b. At the periphery thereof, a steel sphere 3 and a coil spring 6 are alternately arranged at intervals in the circumferential direction so as to be sandwiched between the vertically opposed cycloid curved surfaces 1a and 2a.

In the seismic isolation devices of the above-described fourth and fifth embodiments, the damping coefficient changes according to the amount of elastic deformation of the spherical viscoelastic body 4c in accordance with the amount of movement in the horizontal direction, so that vibration damping suitable for amplitude is achieved. Performance can be exhibited, and the horizontal sliding or rolling movement range of the pedestal 2 on the side of the base B with the damping element 4 composed of the spherical viscoelastic body 4c is determined by the arrangement of the pedestals 1 and 2. Can also be used as a stopper for limiting the pressure.

In the fourth embodiment, the contact surface 1a with the steel sphere 3 and the contact surface 1b with the spherical viscoelastic body 4c of the cradle 1 on the side of the structure A are as shown in FIG. It may be a flat surface, or may be a parabolic curve surface or an arc surface.

In the fifth embodiment, the contact surface 2b of the pedestal 2 on the side of the base B with the spherical viscoelastic body 4c is used.
And the contact surface 2a with the steel sphere 3 as shown in FIG.
It may be a flat surface, or may be a parabolic curve surface or an arc surface.

In each of the above embodiments, the steel ball 3 is used as the rolling element. However, the material is not particularly limited to steel. If the material has high rigidity, a metal other than steel is used. Or a material other than metal.

[0025]

As described above, according to the first to fourth aspects of the present invention, a stacked or spherical viscous member is provided separately from the rolling element between the pedestal on the structure side and the pedestal on the base side. By interposing the damping element made of an elastic body, it is possible to increase the damping coefficient without increasing the frictional resistance of the rolling elements constituting the sliding or rolling device. Therefore, it is usually possible to sufficiently suppress the occurrence of micro-vibration and shaking due to wind, and to greatly attenuate the horizontal movement during an earthquake to improve the vibration control performance. This has the effect that a large seismic isolation effect can be exerted on lightweight structures.

According to the present invention, in addition to the above-described effects, the spring constant is reduced or the damping is caused by the amount of elastic deformation of the spherical viscoelastic body according to the amount of horizontal movement. The vibration suppression performance at the time of the occurrence of an earthquake can be further enhanced by a change in the coefficient.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a basic configuration of a seismic isolation device according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram showing a basic configuration of a seismic isolation device according to a second embodiment.

FIG. 3 is a conceptual diagram showing a basic configuration of a seismic isolation device according to a third embodiment.

FIG. 4 is a conceptual diagram showing a basic configuration of a seismic isolation device according to a fourth embodiment.

FIG. 5 is a plan view of a basic configuration according to the fourth embodiment.

FIG. 6 is a conceptual diagram showing a basic configuration of a seismic isolation device according to a fifth embodiment.

FIG. 7 is a plan view of a basic configuration according to the fifth embodiment.

FIG. 8 is a conceptual diagram showing a modification of the basic configuration according to the fourth embodiment.

FIG. 9 is a conceptual diagram showing a modification of the basic configuration according to the fifth embodiment.

[Explanation of symbols]

 Reference Signs List 1 cradle on structure side 1a cycloid curve surface (sphere contact surface) 2 cradle on base side 2a cycloid curve surface (sphere contact surface) 3 sphere (rolling body) 4 damping element 4a plate-shaped viscoelastic body 4b metal plate 4c sphere Viscoelastic body 5 Sliding or rolling mechanism A Structure B Basic

Claims (7)

[Claims] 1. A rolling element is interposed between a pedestal on a structure side and a pedestal on a foundation side, so that the pedestal on the structure side can be slid or rolled horizontally with respect to the pedestal on the foundation side. A seismic isolation device, wherein a damping element composed of a viscoelastic body is interposed between the two cradles. 2. The seismic isolation device according to claim 1, wherein the damping element comprises a laminated viscoelastic body in which plate-shaped viscoelastic bodies and metal plates are alternately laminated. 3. The seismic isolation device according to claim 1, wherein the damping element is formed of a viscoelastic body formed in a spherical shape. 4. A contact surface of at least one of the cradles with a rolling element is formed as a cycloidal curved surface, a flat surface, a parabolic curved surface, or an arcuate surface.
4. The seismic isolation device according to any one of items 1 to 3. 5. The seismic isolation device according to claim 2, wherein a sliding mechanism is added to a contact surface of the damping element composed of the laminated viscoelastic body with the pedestal on the structure side. 6. A curved line in which a contact surface of at least one of the pedestals with which the damping element composed of the spherical viscoelastic body contacts is allowed to slide or roll within a predetermined range of the damping element. The seismic isolation device according to claim 3 or 4, which is formed on a surface. 7. The cradle having the rolling elements interposed therebetween,
7. The damping element made of the viscoelastic body is disposed so as to also serve as a stopper for limiting a horizontal sliding or rolling movement range of the base-side pedestal.
The seismic isolation device according to any of the above.