JP2000257303A - Base isolation device and base isolation structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively exhibit the function of a base isolation device even if an upper structure is light-weight like a detached house as a base isolation device preventing the upper structure from swinging and securely activate the base isolation device to prevent the upper structure from swinging even when the upper structure inclines in an earthquake. SOLUTION: A support column 5 is provided at the central part of the underface of an upper plate 1, and a sliding member 6 is provided at the lower end of the support column 5 to support the upper plate 1 together with the support column 5 so as to be relatively horizontally slidable against the lower plate 2. The mutual outer peripheral parts of the upper plate 1 and the lower plate 2 are elastically connected to each other by a rubber member 8 which expands when the upper plate 1 slides relative to the lower plate 2. Further, a fitting recess 3 opened to the upper face of the upper plate 1 is formed. A projection 21a protruding downward to the under face of the upper structure 21 is fitted to the fitting recess 3 to connect the upper plate 1 and the upper structure 21.

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 which is provided between an upper structure such as a building and a foundation and suppresses the vibration of the upper structure due to an earthquake. It belongs to the technical field of seismic isolation structure.

[0002]

2. Description of the Related Art Conventionally, as a seismic isolation device of this kind,
For example, as shown in FIG. 6, a laminated rubber type in which a rubber layer c made of natural rubber or the like and a steel plate layer d are alternately laminated between a circular upper plate a and a lower plate b connected to an upper structure and a foundation, respectively. Is well known. This one is
The vertical stiffness of the laminated part supports the load of the superstructure, and against horizontal rolls due to an earthquake, the shear deformation of the rubber layer c and the damping action of the iron or lead plug e provided at the center position in the horizontal direction To absorb the displacement and force of Also,
Instead of the plug e, there is a type in which the rubber layer c is damped by a hydraulic mechanism, and a type in which the rubber layer c has a high attenuation so that the rubber itself exerts a damper function. Since this laminated rubber type seismic isolation device has a simple structure, and can easily predict the seismic force damping performance in the design before construction, the construction work and maintenance after construction are easy, It is widely used in large buildings such as large apartment houses and hospitals.

On the other hand, as a seismic isolation device for preventing a collapse of an earthquake, a fall of furniture and furniture, and a fall in a lightweight upper structure such as a private house, for example, Japanese Patent Application Laid-Open No. Hei 8-3263.
As disclosed in Japanese Patent Publication No. 52-52, a flexible structure is provided between a pair of upper and lower hard members, and a large number of compartments filled with a flow member are formed in the flexible structure, thereby simplifying the structure. It has been proposed that the structure of the superstructure be suppressed by an earthquake with a simple structure.

Further, in recent years, a seismic isolation device combining a slide mechanism such as a bearing and a damper mechanism without using rubber has been known. In this seismic isolation device, for example, two slide mechanisms are connected in a substantially cross shape. Thus, the upper structure can be freely moved in two horizontal directions with respect to the foundation, and a spring, an oil damper or the like is separately added to the slide mechanism to suppress the swing of the upper structure.

Further, as shown in, for example, Japanese Patent Application Laid-Open No. 9-4279, a steel ball is sandwiched from above and below by a parabolic circular steel plate support having a bottom at the center,
It has been proposed to suppress the roll of the upper structure by eliminating the seismic acceleration by the reaction force when the steel ball ascends the lower pan support.

[0006]

However, the above-mentioned conventional laminated rubber type exerts seismic isolation performance due to the shearing force and shear deformation of the laminated rubber layer c, so that the horizontal swinging motion occurs. In order to gain the moving distance due to, it is necessary to increase the number of laminations and secure a predetermined height,
To stably support the superstructure while securing the height,
Since it is necessary to increase the diameter and the size of the apparatus is increased, the installation place is taken and the vertical load is 50 to 100.
Actually, it is used only for large buildings such as hospitals and large apartment buildings of about kg / cm ² .

In addition, the former proposal example (Japanese Patent Laid-Open No. 8-32)
In the seismic isolation device disclosed in Japanese Patent No. 6352), the strength of the flexible structure for supporting the load from the upper structure decreases due to aging, and the height of the upper structure cannot be kept constant. There's a problem. In addition, it is difficult to provide a plurality of compartments inside for manufacturing.

[0008] In a seismic isolation device combining a slide mechanism and a damper mechanism without using rubber, the structure of the slide mechanism and the damper mechanism is required in order to function against seismic force from any direction. Has become very complicated, and the difficulty in designing prior to construction and high cost have become problems, and it has not been widely used.

Further, the latter proposed example (Japanese Patent Laid-Open No. 9-4)
In the seismic isolation device disclosed in Japanese Patent No. 279), there is a problem that the steel structure moves on the parabolic dish cradle in response to the roll due to the earthquake, so that the upper structure also moves in the vertical direction. In addition, since the mechanism for damping the vibration is based on gravity, the upper structure has a vibration behavior close to free vibration, and there is a problem that the vibration is not well controlled.

[0010] The present invention has been made in view of the above points, and an object of the present invention is to provide a seismic isolation device and a seismic isolation structure which suppress the shaking of an upper structure due to an earthquake. Is different from the conventional one, even if the upper structure such as a private house is lightweight, there is no vertical displacement, and the horizontal displacement and force can be effectively suppressed, and The structure is simple, small and lightweight, and even if the upper structure is tilted in the event of an earthquake, the seismic isolation device can be operated reliably to prevent the upper structure from shaking. It is to make.

[0011]

In order to achieve the above object, according to the present invention, a seismic isolation device is provided on a support column fixed to a lower surface other than an outer peripheral portion of an upper plate so as to extend downward. A sliding member that supports the upper plate slidably in a horizontal direction relative to the lower plate together with the support pillar, and an outer peripheral portion of the upper plate and the lower plate are elastically connected to each other so that the upper plate is lower. An elastic body that extends when sliding in a horizontal direction relative to the plate, and a fitting recess that opens on the upper surface of the upper plate, and the fitting recess projects downward from the lower surface of the upper structure. The upper plate and the upper structure are connected by fitting the protrusions provided as described above.

More specifically, according to the first aspect of the present invention, an upper structure having a projecting portion projecting downward on a lower surface and a foundation are provided so as to suppress shaking of the upper structure due to an earthquake. Target seismic isolation devices.

The lower plate connected to the foundation, the upper plate provided to face the upper side of the lower plate, and the lower plate other than the outer peripheral portion of the upper plate are fixed to extend downward. A support column, provided at least one of the lower end of the support column and the upper surface of the lower plate, supports the upper plate together with the support column so as to be slidable relative to the lower plate in the horizontal direction. An elastic body that elastically connects the sliding member and at least a part of the outer peripheral portions of the upper plate and the lower plate, and extends when the upper plate slides relative to the lower plate in a horizontal direction. And a fitting recess formed on the upper surface of the upper plate, the fitting recess being formed so as to be fittable with the protrusion on the lower surface of the upper structure and having a depth smaller than the protrusion amount of the protrusion. The upper plate and the upper structure are connected to each other by fitting the concave portion and the protrusion on the lower surface of the upper structure. And those are.

According to the above configuration, since the upper plate is supported by the support pillar with respect to the lower plate, the height of the upper structure can be stably maintained, unlike the case where the upper plate is supported by rubber. Then, when an earthquake occurs, the upper plate is smoothly slid in the horizontal direction with respect to the lower plate together with the support pillars by the sliding member, and the sudden vibration is lengthened and reduced. On the other hand, the elastic body generates a restoring force for returning the upper plate to the position before sliding by extending, and this restoring force acts as a damping force together with the frictional force acting on the sliding member. Therefore, the horizontal swing of the upper structure can be suppressed without moving the upper structure up and down, and the upper plate or the upper structure can be returned to the position before sliding after the convergence of the earthquake. In addition, since the restoring force of the elastic body and the frictional force of the sliding member can be adjusted, the restoring force can be set to an optimum value according to the weight of the upper structure. Furthermore, when the fitting recess of the seismic isolation device is fitted to the protrusion on the lower surface of the upper structure, the depth of the fitting recess is set smaller than the protrusion amount of the protrusion, so that A gap can be formed between the upper plate of the device and the lower surface of the upper structure, and if the horizontal distance between the fitting recess and the support column is considerably reduced, the upper structure may be tilted during an earthquake. The upper plate itself can be hardly inclined. As a result, a so-called rocking phenomenon in which the support columns are inclined and cannot slide smoothly does not occur. Therefore,
It is possible to reliably operate the seismic isolation device to exhibit a sufficient seismic isolation effect.

According to a second aspect of the present invention, in the first aspect of the present invention, it is assumed that the center axis of the fitting recess and the center axis of the support column substantially coincide with each other. Thus, the upper structure can be stably supported, and even if the upper structure is tilted, the upper plate and the support columns can be reliably prevented from tilting.

According to a third aspect of the present invention, in the first or second aspect, the sliding member is made of a lubricating resin. Thereby, the slidability can be improved and the seismic isolation effect can be further enhanced. It is more preferable that the sliding member has a high compressive strength and a small change with time in the sliding property.

According to the invention of claim 4, according to claim 1, 2, or 3
In the invention, the elastic body is formed of a cylindrical rubber member that connects the entire outer periphery of the upper plate and the lower plate and covers a space between the upper plate and the lower plate.

In this way, regardless of the direction in which the upper plate moves, the cylindrical rubber member expands accordingly and a stable restoring force with no directivity is generated. In addition, since dust and dust can be prevented from entering the sliding portion, stable slidability can be maintained for a long period of time.

According to a fifth aspect of the present invention, a seismic isolation device is provided between an upper structure having a projecting portion projecting downward on a lower surface and a foundation, and the seismic isolation device allows the upper structure to withstand an earthquake. This is an invention of a seismic isolation structure that suppresses shaking.

According to the present invention, the seismic isolation device includes:
A lower plate connected to the foundation, an upper plate provided to face the upper side of the lower plate, and a support column fixed to a lower surface other than the outer peripheral portion of the upper plate so as to extend downward; Provided on at least one of the lower end of the support column and the upper surface of the lower plate,
A sliding member that supports the upper plate together with the support column so as to be slidable relative to the lower plate in a horizontal direction, and at least a part of the outer peripheral portions of the upper plate and the lower plate are elastically connected to each other. An elastic body that extends when the upper plate slides relative to the lower plate in a horizontal direction; and an opening that opens in the upper surface of the upper plate, and is capable of being fitted with a protrusion on the lower surface of the upper structure and having a depth. Is provided with a fitting recess formed to be smaller than the projecting amount of the projecting portion, and by fitting the fitting recess of the seismic isolation device and the projecting portion on the lower surface of the upper structure, It is assumed that the upper structure is connected. According to the present invention, the same function and effect as those of the first aspect can be obtained.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a seismic isolation device A according to an embodiment of the present invention. The seismic isolation device A is provided between an upper structure 21 such as a building and a foundation 23, and the upper structure 21 against an earthquake is provided. Is to suppress the shaking of
When the upper structure 21 is lightweight, such as a private house, the seismic isolation effect is exhibited particularly. The lower surface of the upper structure 21 is a horizontal surface, on which a protruding portion 21a having a circular cross section connected to the upper plate 1 of the seismic isolation device A is formed as described later.

The seismic isolation device A includes a circular stainless steel lower plate 2 connected to the foundation 23 via a flange 11 described later, and a circular circular lower plate 2 provided on the upper side of the lower plate 2. And a stainless steel upper plate 1. The upper plate 1 and the lower plate 2 are composed of outer peripheral members 1a and 2a constituting outer peripheral portions of the upper plate 1 and the lower plate 2, respectively.
a, 2a, and inner peripheral side members 1b, 2b constituting radially inner portions of the upper plate 1, respectively.
The two members 2a and 2b of the lower plate 2 are firmly connected concentrically by screws (not shown) or bolts or the like at portions formed stepwise from each other.

Below the inner peripheral side member 2b of the lower plate 2,
A circular metal flange 11 having a diameter larger than that of the lower plate 2 is fixed by screws or bolts.
Are attached to the foundation 23 by a plurality of bolts 12, 12,... Provided at substantially equal intervals in the circumferential direction on the outer peripheral portion.

At the center of the lower surface of the inner peripheral member 1b of the upper plate 1, the upper end of a substantially cylindrical steel supporting column 5 extending downward is fixedly attached by means of adhesive or bolts. Between the lower end of the support column 5 and the upper surface of the lower plate 2, the upper plate 1 can be slid in a horizontal direction relative to the lower plate 2 together with the support column 5, and A sliding member 6 for supporting the lower surface to be horizontal is provided. The sliding member 6 is made of a lubricating resin such as ultra-high molecular weight polyethylene, high-density polyethylene, polyamide, polytetrafluoroethylene, polyacetal, and the like. , Aramid fiber, carbon fiber, etc., and may further contain a lubricant (solid or liquid). The sliding member 6 has a disk shape having substantially the same diameter as the support column 5, and is attached and fixed to the lower end of the support column 5 concentrically in the axial direction by an adhesive or a bolt.

The entire periphery of the outer peripheral members 1a and 2a constituting the outer peripheral portions of the upper plate 1 and the lower plate 2 is formed by a cylindrical rubber member 8 (elastic) that covers the space between the upper plate 1 and the lower plate 2. Body). This rubber member 8 generates a restoring force that extends when the upper plate 1 slides in any direction in the horizontal direction relative to the lower plate 2 and returns the upper plate 1 to the position before the sliding. It has become. This rubber member 8
Is made of a compounded rubber mainly composed of natural rubber or synthetic rubber, or a composite material in which any of the compounded rubbers is reinforced with fibers. The rubber member 8 is formed in an arc shape such that the thickness of the upper and lower ends is smoother than the central portion in the vertical direction, and the upper plate 1 moves relative to the lower plate 2 in the horizontal direction. When this occurs, the stress concentration is reduced. Further, the entire horizontal surface and vertical surface of each concave portion formed on both upper and lower end surfaces of the rubber member 8 are vulcanized to the opposing surface and the entire outer peripheral surface of the outer peripheral members 1a and 2a of the upper plate 1 and the lower plate 2, respectively. The space between the upper plate 1 and the lower plate 2 is adhered, so that the space is substantially closed. The space between the upper plate 1 and the lower plate 2 covered with the rubber member 8 may be filled with an attenuator made of a liquid viscous material or a powdery or granular polymer material.

At the center of the inner peripheral member 1b of the upper plate 1, an opening is formed on the upper surface of the inner peripheral member 1b so that it can be fitted to the projection 21a on the lower surface of the upper structure 21 and has a depth. A fitting recess 3 having a circular section is formed to be smaller than the protrusion amount of the protrusion 21a. The inner diameter of the fitting recess 3 (the outer diameter of the protruding portion 21 a) is smaller than the outer diameter of the support column 5. The fitting recess 3 is formed concentrically with the support column 5 so that the central axis extending in the vertical direction substantially coincides with the central axis of the support column 5. Then, the fitting recess 3
The upper plate 1 and the upper structure 21 are connected to each other by fitting of the upper plate 1 and the protrusion 21a on the lower surface of the upper structure 21. Note that the depth of the fitting recess 3 is smaller than the thickness of the upper plate 1, so that the fitting recess 3 is constituted only by the upper plate 1.

A method of assembling the seismic isolation device A having the above configuration will be described with reference to FIG. First, the outer peripheral members 1a and 2a of the upper plate 1 and the lower plate 2 are respectively fitted into the concave portions on both upper and lower end surfaces of the rubber member 8, and the entire horizontal surface and vertical surface of each concave portion are opposed to the outer peripheral members 1a and 2a. Vulcanized and adhered to the entire surface and the outer peripheral surface.

Subsequently, a flange 11 is attached and fixed to the lower surface of the inner peripheral member 2b of the lower plate 2 in advance with screws or bolts, and the inner peripheral member 2b is screwed to the outer peripheral member 2a. To join.

Next, after the fitting recess 3 is formed on the upper surface of the inner peripheral side member 1b of the upper plate 1, the supporting column 5 and the sliding member 6 are fixed on the lower surface. The inner peripheral member 1 of the upper plate 1
The seismic isolation device A is completed by connecting b to the outer peripheral member 1a with screws or bolts.

The seismic isolation device A is connected to the upper structure 21 and the foundation 2
3, the flange 11 is attached and fixed to the foundation 23 by the bolts 12, while the projection 21 a on the lower surface of the upper structure 21 is inserted and fitted into the fitting recess 3 of the seismic isolation device A. At this time, the depth of the fitting concave portion 3 is
Is smaller than the protrusion amount of the
The front end surface (lower end surface) of 1a contacts the bottom surface of the fitting concave portion 3,
A gap is formed between the upper plate 1 and the lower surface of the upper structure 21 (see FIG. 1).

As described above, in the seismic isolation device A provided between the upper structure 21 and the foundation 23, the upper plate 1 is supported by the supporting columns 5 and the sliding members 6 with respect to the lower plate 2, Since the moving member 6 is made of a lubricating resin having a high compressive strength, the height of the upper structure 21 can be stably maintained, unlike the case where the moving member 6 is supported by rubber. In addition, since the central axis of the fitting concave portion 3 substantially coincides with the central axis of the support column 5, the load of the upper structure 21 acts on the central axis of the support column 5 to stabilize the upper structure 21. Can be supported.

When an earthquake occurs, the upper plate 1 smoothly slides in the horizontal direction relative to the lower plate 2 together with the support columns 5 by the sliding member 6 having a low coefficient of friction, so that a sudden vibration is generated. Periodically softens. On the other hand, since the rubber member 8 is deformed and extended in the direction in which the upper plate 1 is displaced from the lower plate 2, a restoring force is generated in the rubber member 8 to return the upper plate 1 to the position before sliding. This restoring force acts as a damping force together with the frictional force acting between the lower plate 2 and the sliding member 6. As a result, the horizontal swing of the upper structure 21 can be suppressed without moving the upper structure 21 up and down, and the object installed inside the building can be prevented from falling down. Moreover, after the convergence of the earthquake, the upper plate 1 and the upper structure 21 can be returned to the positions before sliding. Further, the restoring force of the rubber member 8 and the frictional force between the lower plate 2 and the sliding member 6 can be changed by changing the material, size, sectional shape, etc. of the rubber member 8 and the material of the sliding member 6, respectively. , Can be set to an optimum value according to the weight of the upper structure 21. Further, the rubber member 8 generates the same restoring force when the upper plate 1 moves in any direction in the horizontal direction with respect to the lower plate 2, so that the rubber member 8 functions in the same manner against seismic force from any direction. Can be done.

Further, even if the lower surface of the upper structure 21 is inclined obliquely with respect to the horizontal direction when an earthquake occurs, a gap is formed between the upper plate 1 of the seismic isolation device and the lower surface of the upper structure 21 and Since the central axis of the fitting recess 3 is substantially coincident with the central axis of the support column 5, the upper plate 1 itself does not tilt. That is, the upper plate 1 is connected to the flange 1 in the same manner as the connection between the lower plate 2 and the foundation 23.
1 and the upper structure 21 is connected to the upper structure 21, the flange 11 provided on the upper plate 1 is connected to the upper structure by the bolts 12 at the outer peripheral portion (outer than the outer peripheral surface of the upper plate 1). When the lower surface of the upper structure 21 is tilted obliquely with respect to the horizontal direction, the upper plate 1, the support column 5, and the sliding member 6 are also tilted, so that a so-called rocking phenomenon occurs in which the sliding is braked. Although it may occur, in the present invention, such a locking phenomenon can be prevented and the seismic isolation device A can be reliably operated.

In addition, when the upper structure 21 vibrates vertically when an earthquake occurs, the protrusion 21a on the lower surface of the upper structure 21 can move upward relative to the fitting recess 3. In addition, the upper plate 1 is not pulled up by the upper structure 21 (the distance between the upper plate 1 and the lower plate 2 is increased), and as a result, a large tensile force is prevented from acting on the rubber member 8. Can be.

In the above-described embodiment, the fitting recess 3 is formed only of the upper plate 1 so that the depth thereof is smaller than the thickness of the upper plate 1. However, as shown in FIG. The concave portion 3 may be constituted by both the upper plate 1 and the support column 5 so as to reach the upper end of the support column 5. In this way, a sufficient fitting length can be obtained even if the thickness of the upper plate 1 is small, and even if the upper structure 21 vibrates in the vertical direction, the protrusion 2
1a can be prevented from falling out of the fitting recess 3. Further, the bottom surface of the fitting recess 3 may be the top surface of the support column 5. When the fitting recess 3 is formed by the upper plate 1 and the support pillar 5 as described above, the inner diameter of the fitting recess 3 is smaller than the outer diameter of the support pillar 5 as in the above embodiment. Although it is necessary, when the fitting recess 3 is constituted only by the upper plate 1, the inner diameter of the fitting recess 3 may be equal to or larger than the outer diameter of the support column 5.

In the above embodiment, the center axis of the fitting recess 3 and the center axis of the support column 5 are substantially coincident with each other. However, both center axes may be shifted from each other in the horizontal direction. However, it is desirable that the center axis of the fitting concave portion 3 pass through the inside of the outer peripheral surface of the support column 5.

Further, in the above-described embodiment, the cylindrical rubber member 8 which covers the space between the upper plate 1 and the lower plate 2 is used as the elastic body, but, for example, a plurality of coil springs are provided at substantially equal intervals in the circumferential direction. It is also possible to arrange them. In addition, the elastic body,
As shown in FIG. 4, similarly to the laminated portion in the conventional laminated rubber type seismic isolation device, a plurality of rubber layers 15a, 15a,
, And rigid plate layers 15b, 15b,... Made of a steel plate or the like are alternately stacked in the vertical direction.
CC device), and the plurality of laminates 15, 1
May be arranged at substantially equal intervals in the circumferential direction. In this way, when an earthquake occurs, a shear force acts on each rubber layer 15a of each laminate 15, and this shear force becomes a restoring force. Like the case where the rubber member 8 is used, even if the upper plate 1 moves in any direction in the horizontal direction with respect to the lower plate 2, substantially the same restoring force is generated in the entire stacked body 15, 15,. And each of the laminates 15
It is also easy to adjust the restoring force, so that the same operation and effect as in the above embodiment can be obtained. The relationship between the shearing force generated in each rubber layer 15a of the laminate 15 and the relative movement amount of the upper plate 1 and the lower plate 2 is determined by the tensile force generated in the rubber member 8 and the upper plate 1 and the lower plate in the above embodiment. Compared to the relationship with the relative movement amount of No. 2, it is closer to linear and easy to handle.

In addition, in the above-described embodiment, the sliding member 6 made of a lubricating resin is fixed to the support column 5.
The present invention can be applied to any other resin or metal as long as the resin and metal are surely supported and have good slidability. Then, a sliding member 6 having substantially the same size as the lower plate 2 may be attached and fixed to the upper surface of the lower plate 2 so that the support column 5 slides on the upper surface of the sliding member 6. Further, the support column 5 itself may be made of a material having good slidability. A sliding contact surface is provided at the lower end of the support column 5 so as to be in sliding contact with the upper surface of the lower plate 2. 2 may be supported so as to be slidable in the horizontal direction relative to the second member 2.

In the above embodiment, the fitting recess 3 (projection 21a on the lower surface of the upper structure 21) of the seismic isolation device A has a circular cross section, but may have a polygonal shape. The upper and lower plates 1 and 2, the support pillar 5, the sliding member 6, and the flange 11 can be formed in a polygonal shape.

[0040]

Next, a specific embodiment will be described. Four seismic isolation devices A were manufactured in the same manner as in the above embodiment. As shown in FIG. 5, each of the seismic isolation devices A is connected to each of the columns 21 located at the four corners of the upper structure 21 in the private house.
b and the base 23. A pin is implanted on the lower surface of each pillar 21b to form a protrusion 21a.
a was fitted to the fitting recess 3 of each seismic isolation device A. on the other hand,
The lower plate 2 and the foundation 23 of each seismic isolation device A are connected to the flange 11 fixed to the lower side of the lower plate 2 by the bolts 12.
It was connected by attaching and fixing to. This foundation 23 is set on a plurality of rollers for testing, and
It is possible to vibrate by applying vibration in the horizontal direction with respect to. Here, the horizontal spring constant of each of the seismic isolation devices A is 45 kgf / cm, and the horizontal damping coefficient is 34 kgf / cm.
kgf · s / cm. The weight of the upper structure 21 was 40 t, which is almost the same as that of a general wooden house.

Then, a seismic wave observed in the Hyogoken-Nanbu Earthquake was input to the foundation 23 in the horizontal direction, and the vibration damping effect of the upper structure 21 was examined. As a result, the maximum acceleration of the upper structure 21 in the horizontal direction was reduced to about 1/4, and it was confirmed that the seismic isolation effect was sufficiently exhibited. This damping effect was the same even when the upper plate 1 was connected to the lower surface of each column 21b via the flange 11, similarly to the connection between the lower plate 2 and the foundation 23. That is, the fitting recess 3 and the protrusion 2
It was confirmed that even when the upper plate 1 and the upper structure 21 were connected by fitting with 1a, the seismic isolation performance was not different from the case of connecting via the flange 11. On the other hand, even when a load oblique to the horizontal direction was applied to the upper structure 21 during the vibration, the rocking phenomenon did not occur, and the seismic isolation performance was not affected at all.

[0042]

As described above, according to the first or fifth aspect of the present invention, the seismic isolation device is provided with a support column fixed to the lower surface of the upper plate so as to extend downward, and the upper plate together with the support column. The upper plate and the lower plate are elastically connected to each other, and the upper plate and the lower plate are elastically connected to each other. An elastic body that extends when sliding in the horizontal direction, and a fitting recess that opens on the upper surface of the upper plate, and a projection provided in the fitting recess so as to project downward on the lower surface of the upper structure. By connecting the upper plate and the upper structure by mating with each other, the seismic isolation function that reduces and absorbs horizontal vibration without raising or lowering even the lightweight upper structure is effective. A small and lightweight seismic isolation device that can be used in It is possible to reliably operate the seismic isolation device is prevented.

According to the second aspect of the present invention, the center axis of the fitting recess is substantially aligned with the center axis of the support column, so that the upper structure is stably supported and the occurrence of the locking phenomenon is reliably prevented. can do.

According to the third aspect of the present invention, since the sliding member is made of a lubricating resin, the sliding characteristics can be stabilized for a long period of time.

According to the fourth aspect of the present invention, the elastic body is a cylindrical rubber member that connects the entire outer periphery of the upper plate and the lower plate and covers the space between the upper plate and the lower plate. Since the dust and dirt do not enter the inside of the rubber member without being influenced by the direction of the seismic force, stable damping force and restoring force can be secured for a long period of time.

[Brief description of the drawings]

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

FIG. 2 is an exploded view showing an assembling procedure of the seismic isolation device.

FIG. 3 is a view corresponding to FIG. 1 showing a modified example of a fitting recess.

FIG. 4 is a view corresponding to FIG. 1 showing a modification of the embodiment using a laminate as an elastic body.

FIG. 5 is a schematic view showing a procedure of a test for applying a seismic isolation device to a private house and examining the seismic isolation effect thereof.

FIG. 6 is a sectional view showing a conventional laminated rubber type seismic isolation device.

[Explanation of symbols]

 A seismic isolation device 1 upper plate 2 lower plate 3 fitting concave portion 5 support column 6 sliding member 8 rubber member (elastic body) 15 laminated body (elastic body) 21 upper structure 21a projecting portion 23 foundation

Claims (5)

[Claims] 1. A seismic isolation device which is provided between an upper structure having a projecting portion projecting downward on a lower surface and a foundation, and which suppresses shaking of the upper structure due to an earthquake. A lower plate connected to a foundation, an upper plate provided facing the upper side of the lower plate, a support column fixed to a lower surface other than an outer peripheral portion of the upper plate so as to extend downward, and the support A sliding member provided on at least one of the lower end of the column and the upper surface of the lower plate, and supporting the upper plate together with the support column so as to be slidable relative to the lower plate in a horizontal direction; An elastic body that elastically connects at least a part of the outer peripheral portions of the upper plate and the lower plate and extends when the upper plate slides relative to the lower plate in a horizontal direction; It is open on the upper surface and can be fitted with the protrusion on the lower surface of the upper structure, and the depth is greater than the protrusion amount of the protrusion. The upper plate and the upper structure are connected to each other by fitting the fitting recess with a protrusion on the lower surface of the upper structure. And seismic isolation device. 2. The seismic isolation device according to claim 1, wherein the center axis of the fitting recess and the center axis of the support column substantially coincide with each other. 3. The seismic isolation device according to claim 1, wherein the sliding member is made of a lubricating resin. 4. The seismic isolation device according to claim 1, 2 or 3, wherein the elastic body connects the entire outer periphery of the upper plate and the lower plate and covers the space between the upper plate and the lower plate. A seismic isolation device comprising a rubber member. 5. A seismic isolation device is provided between an upper structure having a projecting portion projecting downward on a lower surface thereof and a foundation, and the seismic isolation device suppresses the swing of the upper structure due to an earthquake. The seismic isolation device includes: a lower plate connected to the foundation; an upper plate provided to face the upper side of the lower plate; and a lower surface other than an outer peripheral portion of the upper plate. A support column fixed to extend downward,
A sliding member provided on at least one of the lower end portion of the support column and the upper surface of the lower plate, and supporting the upper plate together with the support column so as to be slidable relative to the lower plate in a horizontal direction; An elastic body that elastically connects at least a part of an outer peripheral portion of the upper plate and the lower plate and extends when the upper plate slides in a horizontal direction relative to the lower plate; A fitting recess formed in the upper surface of the base structure, the fitting recess being formed so as to be fittable with the protrusion on the lower surface of the upper structure and having a depth smaller than the protrusion amount of the protrusion. An upper plate of the seismic isolation device and the upper structure are connected by fitting of the upper structure and a protrusion on the lower surface of the upper structure.