JP2002130370A - Seismic isolator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seismic isolator which can effectively reduce vertical vibration occurring during earthquakes. SOLUTION: The seismic isolator is characterized in that an inside tube 15 and an outside tube 16 are installed in a standing manner upon a lower flange 14 disposed on a substructure 2 side of a structure, a top of the inside tube 15 is closed by a top plate 17, a pressure plate 19 is installed freely movable vertically between the top plate 17 and the lower flange 14 and a spring member 20 is interposed between the pressure plate 19 and the top plate 17, on the other hand, a first plenum 21 is formed and a tubelike support member 22 suspended from an upper flange 13 arranged on a superstructure 1 side is installed freely movable vertically between the inside tube 15 and the outside tube 16, and, by providing an annular ring shaped movable member 23 on a bottom end of the support member 22, a second plenum 24 is formed between the movable member 23 and the lower flange 14, and further then the first and the second plenum 21, 24 are communicated each other via orifice 25 and are filled with a liquid L.

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 capable of exerting a seismic isolation function and a damping function particularly against vertical vibrations.

[0002]

2. Description of the Related Art In recent years, in order to ensure the safety of a structure against earthquakes, seismic isolation devices are interposed between the foundations of the structures and pillars on the middle floors, etc. Various seismic isolation structures have been developed to attenuate the vibrations that propagate to the structure and reduce the stress and deformation generated in the frame of the structure. Conventionally, seismic isolation devices used for such seismic isolation structures are roughly classified into an elastic bearing system using laminated rubber or the like, and a sliding bearing system or a rolling bearing system.

[0003] The seismic isolation device using an elastic bearing using the above-mentioned laminated rubber is a bearing member having a large load supporting capacity and a horizontal displacement capacity by alternately stacking steel plates and rubber sheets in multiple layers. The relative displacement in the horizontal direction that occurs sometimes is absorbed by the elasticity of the rubber, and the natural period of the structure is made longer to reduce the influence of seismic force.

[0004] On the other hand, a seismic isolation device of a sliding bearing system or a rolling bearing system uses a sliding member or a rolling member interposed between the structure and the foundation to control relative displacement between the structure and the foundation during an earthquake. By permitting, seismic force is prevented from directly acting on the building.

[0005]

However, such a conventional seismic isolation device exerts a seismic isolation effect exclusively on a horizontal earthquake motion, and is therefore resistant to the vertical motion of a structure. This has the disadvantage that effective seismic isolation cannot be achieved. Therefore, development of a seismic isolation device that effectively reduces vibration in the vertical direction in particular is desired.

[0006] The present invention has been made in view of such circumstances, and can be applied to a vertical vibration generated during an earthquake or the like.
It is an object of the present invention to provide a seismic isolation device capable of effectively reducing this.

[0007]

According to a first aspect of the present invention, there is provided a seismic isolation device that is interposed between upper and lower structures of a structure to reduce seismic force, and is disposed on a lower structure side. An inner pipe and an outer pipe are erected on a lower flange to be closed, an upper portion of the inner pipe is closed by a top plate, and a pressure receiving plate is provided between the top plate and the lower flange so as to be movable up and down. A spring member is interposed between the pressure receiving plate and the lower flange, and a first space is formed in the other.
By inserting a tubular support member suspended from an upper flange disposed on the upper structure side between the inner pipe and the outer pipe so as to be vertically movable, and providing an annular movable member at the lower end of the support member. Between the movable member and the lower flange,
And the first and second spaces are communicated with each other via an orifice, and the first and second spaces are filled with a fluid.

A seismic isolation device according to a second aspect of the present invention is a seismic isolation device interposed between upper and lower structures of a structure to reduce seismic force, wherein the lower flange is disposed on the lower structure side. An inner tube and an outer tube are erected, an upper portion between the inner tube and the outer tube is closed with an annular top plate, and an annular pressure receiving plate is provided between the top plate and the lower flange so as to be vertically movable, and A spring member is interposed between one of the pressure receiving plate and the top plate and between the pressure receiving plate and the lower flange, and a first space is formed on the other, and an upper flange disposed on the upper structure side The support member suspended from is vertically inserted into the inner tube, and a movable member is provided at a lower end portion of the support member to form a second space between the movable member and the lower flange, and The first and second spaces are communicated with each other via an orifice. Together it is characterized in that formed by filling the fluid in the first and second space.

Furthermore, in a seismic isolation device according to a third aspect, the seismic isolation member having the configuration according to the first or second aspect and the seismic isolation member using laminated rubber are disposed in layers in the vertical direction. It is characterized by being done.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) FIGS.
1 shows a first embodiment of a seismic isolation device according to the present invention,
In this seismic isolation device 10, a seismic isolation member (seismic isolation device) 11 and a seismic isolation member 12 are vertically arranged in layers and integrated. The seismic isolation member 11 is a superstructure 1 of a structure.
Flange 13 attached to the upper part and seismic isolation member 1 below
2 and a lower flange 14 for integration, and an inner pipe 15 and an outer pipe 16 formed of a steel pipe are coaxially erected on the lower flange 14. A disk-shaped top plate 17 made of a steel plate is joined to upper end portions of the inner tube 15 and the outer tube 16.

A steel column 18 for reinforcement is provided at the center of the inside of the inner tube 15, and upper and lower ends of the steel column 18 are joined to the top plate 17 and the lower flange 14, respectively. A disk-shaped pressure receiving plate 19 made of a steel plate is provided in the inner tube 15 so as to be vertically movable along the steel column 18. The outer periphery of the pressure receiving plate 19 and the inner tube 15 and the steel column 18 are provided. And a seal for liquid-tight sealing is interposed therebetween. Further, a disc spring (spring member) 20 is interposed between the pressure receiving plate 19 and the top plate 17. Here, a hole having an inner diameter larger than the outer diameter of the steel column 18 is formed in the center of the disc spring 20, and the steel column 18 is inserted into the hole. In addition, a space (first space) 21 to be described later filled with a fluid is provided between the pressure receiving plate 19 and the lower flange 14.
Are formed.

On the other hand, on the lower surface of the upper flange 13, a support member 22 made of a steel pipe is vertically provided. A lower portion of the support member 22 is vertically movably inserted between the inner tube 15 and the outer tube 16 from an opening formed in the top plate 17, and has an annular movable plate ( Movable member) 23
Are joined. A seal is provided on the outer periphery of the movable plate 23 so as to seal the space between the movable plate 23 and the opposed wall surface in a liquid-tight manner, so that a space (second space portion) is also provided between the movable plate 23 and the lower flange 14. 24 are formed. These spaces 21 and 22 are communicated with each other via an orifice 25 formed at the lower end of the inner tube 15, and water, viscous fluid, hydraulic oil, silicone oil, A fluid L such as water glycol is filled.

Further, between the lower flange 14 of the seismic isolation member 11 having the above structure and the lower structure 2 of the structure, the seismic isolation device 12 is provided in a layered manner. This seismic isolation device 1
2) A thin steel plate and a highly elastic rubber sheet are bonded in a multilayered manner on both sides and integrated, and a lead plug or the like having hysteresis damping property is inserted into the center of the thin steel plate or a high elastic rubber sheet. Some have a function of absorbing the horizontal relative displacement generated during an earthquake by the elasticity of the rubber sheet, making the natural period of the upper structure 1 longer, and having a vibration damping function, such as a multilayer of rubber and the like. It is suitable. Then, the upper flange 26 of the seismic isolation member 12 is connected to the lower flange 14 of the seismic isolation member 11 by bolts, nuts, and the like, so that they are integrally assembled to form the seismic isolation member 1.
Two lower flanges 27 are attached to the lower structure 2.

FIG. 6 shows a modification of the first embodiment. In this seismic isolation device 10 ', a plate is provided between the pressure receiving plate 19 and the lower flange 14 of the seismic isolation member 11'. With the spring (spring member) 20 interposed,
A space (first space) 21 is formed between the pressure receiving plate 19 and the upper flange 13. Further, an inner pipe 28 is further provided inside the inner pipe 15, and an orifice 29 is provided at an upper end of the inner pipe 28.
Thus, the spaces 21 and 24 are communicated with each other by a flow path from the orifice 25 to the orifice 29 through the space between the inner tubes 15 and 28.

The seismic isolation devices 10 and 10 'having the above configuration
According to this, when a horizontal vibration is generated between the upper and lower structures 1 and 2 during an earthquake or the like, as shown in FIG. 4, the seismic isolation member 12 is elastically deformed to mitigate this. And can be attenuated. Also, as shown in FIG.
When a vertical vibration acts between the upper and lower structures 1 and 2, the support members 22 of the seismic isolation devices 11 and 11 'integrated with the upper structure 1 move up and down, and the pressure of the fluid L fluctuates. Arises
As a result, the disk spring (spring member) 20 expands and contracts via the pressure receiving plate 19, so that the above-described vibration is reduced. In parallel with this, the damping effect is obtained by frictional resistance when the coned disc spring (spring member) 20 expands and contracts, and the viscous resistance when the fluid L passes through the orifice 25 or the orifices 25 and 29 also increases. The damping effect is exhibited.

Therefore, according to the seismic isolation devices 10 and 10 ', effective seismic isolation effect and vibration damping effect can be exhibited with respect to horizontal and vertical vibrations. At this time, as shown schematically in FIG. 7 (corresponding to FIG. 1), the movable plate 23 at the lower end of the support member 22 is moved vertically by δ1
When it moves, the height of the fluid L in the space 24 likewise rises and falls by δ1. As a result, assuming that the area of the movable plate 23 is A, the volume of the fluid moving between the spaces 24 and 21 via the orifice 25 is A × δ1. On the other hand, assuming that the vertical movement of the pressure receiving plate 19 is δ2 and its area is B, the volume is B ×
Since it is equal to δ2, A × δ1 = B × δ2.
= Δ1 × (A / B).

Therefore, by making A / B smaller as B> A, the vertical movement δ1 of the movable plate 23 with respect to the vertical movement δ2 of the pressure receiving plate 19 becomes larger, and as a result, the upper structure 1 moves relatively vertically. The spring constant of the movable plate 23 when vibrating can be made smaller than the spring constant of the disc spring (spring member) 20.

(Embodiment 2) FIG. 8 shows a second embodiment of a seismic isolation device according to the present invention, in which the same components as those shown in FIG. The description will be simplified. As shown in FIG. 8, in the seismic isolation device 30, the seismic isolation member (seismic isolation device) 31 and the seismic isolation member 12 are vertically arranged in layers and integrated. Here, in the seismic isolation device 31, the inner pipe 32 is attached to the lower flange 14.
And an outer tube 33 is erected, and an upper end between the inner tube 32 and the outer tube 33 is closed by an annular top plate 34.

An annular pressure receiving plate 35 is provided between the top plate 34 and the lower flange 14 so as to be vertically movable, and a plurality of pressure receiving plates 35 are provided between the pressure receiving plate 35 and the top plate 34 along the circumferential direction. The coil spring (spring member) 36 is interposed. Thus, a space (first space) 37 in which the same fluid L is filled is formed between the pressure receiving plate 35 and the lower flange 14. On the other hand, at the center of the upper flange 13 attached to the upper structure 1, a columnar bearing member 38 is provided with an inner pipe 32.
A movable plate (movable member) 39 made of a steel plate is joined to the lower end of the support member 38.

Thus, the movable plate 39 and the lower flange 1
4, a space (second space) 40 in which the fluid L is filled is formed. These spaces 37 and 40 filled with the fluid L are communicated with each other via an orifice 41 formed at the lower end of the inner tube 32.

In the seismic isolation device 30 having the above configuration, similarly to the first embodiment, when the vertical vibration acts between the upper and lower structures 1 and 2, the upper structure 1 The support member 38 of the seismic isolation device 31 integrated with the upper and lower members moves up and down, causing a change in the pressure of the fluid L. As a result, the pressure receiving plate 35
The vibration can be reduced by the expansion and contraction of the plurality of coil springs 36, and the damping effect of the vibration can be exhibited by viscous resistance when the fluid L passes through the orifice 41. Therefore, the seismic isolation device 30 can also exhibit effective seismic isolation effects and vibration damping effects against horizontal and vertical vibrations as in the first embodiment. it can.

In the first embodiment, only the case where the disc spring 20 is used as the spring member has been described. Instead, a plurality of coil springs similar to those shown in the second embodiment are used. And other spring members can be used. Further, the steel column 18 is provided for structural reinforcement, and when the reinforcement is not necessary, the steel column 18 can be deleted.

[0023]

As described above, according to the seismic isolation device according to any one of claims 1 to 3, it is possible to reduce the vertical vibration generated between the upper and lower structures during an earthquake or the like. In particular, according to the seismic isolation device of claim 3, the two sets of seismic isolation members arranged in parallel reduce not only vertical vibrations but also horizontal vibrations. On the other hand, it is possible to obtain an effect that both can exert an effective seismic isolation effect.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II of FIG.

FIG. 3 is a sectional view taken along line III of FIG.

4A and 4B are side views showing an operation state of the seismic isolation device of FIG. 1, wherein FIG. 4A is a normal state, FIG. 4B is a state when a relative displacement in the right direction occurs, and FIG. This shows a state when a relative displacement occurs.

5A and 5B are side views showing an operation state of the seismic isolation device of FIG. 1, wherein FIG. 5A shows a normal state, FIG. 5B shows a state when a downward relative displacement occurs, and FIG. This shows a state when a relative displacement occurs.

FIG. 6 is a longitudinal sectional view showing a modification of the first embodiment.

FIG. 7 is a schematic configuration diagram (corresponding to FIG. 1) schematically showing a basic configuration of the present invention.

FIG. 8 is a longitudinal sectional view showing a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper structure 2 Lower structure 10, 10 ', 30 Seismic isolation device 11, 11', 31 Seismic isolation member (seismic isolation device) 12 Seismic isolation member 13, 26 Upper flange 14, 27 Lower flange 15, 28, 32 Inner pipe 16, 33 Outer pipe 17, 34 Top plate 18 Steel column 19 , 35 pressure receiving plate 20 disc spring (spring member) 21, 37 space (first space) 22, 38 support member 23, 39 movable plate (movable member) 24, 40 space (second space) 25, 29, 41 Orifice 36 Coil spring (spring member) L Fluid

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) F16F 15/02 F16F 15/02 G 15/023 15/023 15/06 15/06 A

Claims (3)

[Claims] A seismic isolation device interposed between upper and lower structures of a structure to reduce seismic force, wherein an inner pipe and an outer pipe are erected on a lower flange provided on the lower structure side. ,
An upper portion of the inner pipe is closed by a top plate, and a pressure receiving plate is provided between the top plate and the lower flange so as to be vertically movable, and between the pressure receiving plate and the top plate, and between the pressure receiving plate and the lower flange. A spring member is interposed in one of
A first space is formed on the other side, and an annular bearing member suspended from an upper flange provided on the upper structure side is vertically movably inserted between the inner pipe and the outer pipe,
By providing an annular movable member at the lower end of the support member, a second space is formed between the movable member and the lower flange, and the first and second spaces are connected via orifices. To communicate with each other
And a second space portion filled with a fluid. 2. A seismic isolation device interposed between upper and lower structures of a structure to reduce seismic force, wherein an inner pipe and an outer pipe are erected on a lower flange disposed on the lower structure side. ,
An upper portion between the inner tube and the outer tube is closed by an annular top plate, and an annular pressure receiving plate is provided between the top plate and the lower flange so as to be vertically movable, and the pressure receiving plate and the top plate A spring member is interposed in one of the space and the pressure receiving plate and the lower flange, and a first space is formed in the other, and is suspended from an upper flange disposed on the upper structure side. By inserting a support member into the inner tube so as to be vertically movable and providing a movable member at a lower end of the support member, a second space is formed between the movable member and the lower flange, and The first and second spaces are communicated with each other via an orifice, and
And a second space portion filled with a fluid. 3. A seismic isolation device characterized in that the seismic isolation member having the configuration according to claim 1 or 2 and a seismic isolation member using laminated rubber are arranged vertically in layers. .