JPH10220064A - Base isolation laminated rubber bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure of a base isolating laminated rubber bearing which can use a material having a low shearing rigidity so that has been hardly be able to be used in view of a problem of setting ability, and which can make the inherent period of a light base-isolated structure periodical by lowering the crosswise rigidity thereof so as to enhance the base isolation effect, and which can offer sufficient countermeasure against a fire or the like by preventing flamable elastomer from being exposed to the outside. SOLUTION: A laminated rubber bearing 10 is composed of a ring-like constraining frame 11, a sheet-like elastomer 12 arranged in a hollow part 11a of the constraining frame 11, intermediate steel plates 13 laminated over the upper and lower surfaces of the constraining frame 11, which are alternately stacked one upon another so as to form a laminated rubber bearing body 14. Further, stationary flanges 15a, 15b are fixed to the upper and lower surfaces of the laminated rubber bearing body 14. Further, lead plugs 16 supported by the stationary flanges 15a, 15b are fitted in the planar center part of the laminated rubber bearing body 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation laminated rubber bearing for a building such as a building or a detached house, or a civil structure such as a bridge, and more particularly to a high vertical rigidity and a lower horizontal level than before. The present invention relates to a laminated rubber bearing capable of realizing shear rigidity.

[0002]

2. Description of the Related Art Conventionally, as a structure of a seismic isolation bearing for a building such as a building or a detached house, or a civil structure such as a bridge, for example, as shown in FIGS. A plurality of unvulcanized rubber sheets 1 having a low thickness and an intermediate steel sheet 2 subjected to an adhesive treatment are laminated and integrally vulcanized and formed.
a and 3b are vulcanized and bonded to each other, and a flange-integrated laminated rubber bearing, or as shown in FIG. 8, an unvulcanized rubber sheet 1 and a plurality of bonded intermediate steel plates 2 are laminated, and Vulcanization molding integrally through the connecting steel plates 4a, 4b,
A flange-assembled laminated rubber bearing fixed by a plurality of fastening bolts 5 is known.

[0003]

By the way, the structure of the seismic isolation laminated rubber bearing as described above is such that the rubber layer made of the rubber sheet 1 protrudes outside the intermediate steel sheet 2 against the vertical load.
The structure is constrained by adhesion to the rubber layer, so that in the case of a vertical load, a non-compressive characteristic of the rubber forms a hydrostatic triaxial compressive stress state at the center of the rubber layer, thereby increasing the rigidity in the vertical direction.

On the other hand, with respect to the horizontal displacement, the intermediate steel plate 2 does not restrain the shear deformation of the rubber sheet 1, and the shear deformation of the laminated rubber becomes a shear deformation of the rubber itself and shows a soft horizontal movement. The lower the horizontal rigidity of the laminated rubber bearing, the longer the natural period of the seismic isolation structure (generally, preferably about 4 to 5 seconds), but even if natural rubber is used, the shear rigidity is set to 4 kgf / cm ² or less. It is difficult to do.

When a soft elastomer material is used, long-term creep deformation becomes large, there is a problem in dimensional stability in the vertical direction such as protruding from an intermediate steel sheet, and further, a flammable material against fire such as an earthquake. However, there is also a problem that it is easy to ignite because of being exposed on the surface. As mentioned above,
The seismic isolation laminated rubber bearing has low horizontal rigidity, high vertical rigidity,
Stability of creep characteristics due to long-term vertical load, etc.
Although multifaceted performance is required, conventional laminated rubber bearings cannot fully satisfy the above requirements because they are all based solely on rubber properties and adhesive strength. In this case, it is difficult to achieve 4-second seismic isolation because the horizontal stiffness is not sufficiently low, and the technical difficulty is further increased if the upper class is lighter, such as in a detached house.
There has been a demand for a technique for sufficiently reducing the horizontal rigidity of existing laminated rubber bearings.

The present invention has been devised in view of such a conventional problem, and allows a conventional integrated laminated rubber bearing to share the roles of vertical load resistance and horizontal movability. Low shear stiffness material, which was difficult to use due to the problem of setability, can be used.By lowering the lateral stiffness, it is possible to make the natural period of light seismic isolated structures periodic and improve the seismic isolation effect. It is another object of the present invention to provide a structure of a seismic isolation laminated rubber bearing that can sufficiently cope with a fire or the like by preventing a combustible elastomer from being exposed to the outside.

[0007]

According to the present invention, in order to achieve the above object, an elastomer of a laminated rubber bearing main body is disposed in a hollow portion of a restraining frame, and the restraining frame and an intermediate steel plate slide horizontally. Possible and alternately laminated, the upper and lower surfaces of the elastomer arranged in the hollow part of the restraint frame are sealed with an intermediate steel plate and upper and lower fixing flanges, and high vertical rigidity and low lateral rigidity in the vertical load supporting state The gist is that they are configured to be compatible.

The sliding surface between the restraining frame and the intermediate steel plate is used as a sliding bearing, and a lead plug supported by a vertical fixing flange is provided at the center of the plane of the laminated rubber bearing main body. It is intended to be a damping rubber. Further, the inner wall surface of the hollow portion of the restraint frame and the elastomer may be made non-adhesive, or an O-ring may be interposed between the inner wall surface of the hollow portion of the restraint frame and the elastomer.

The present invention is constructed as described above, wherein the conventional laminated rubber bearing having an integrated structure is configured to share the roles of vertical load resistance and horizontal movability, and the vertical support is made of a metal part. The restoring force characteristics are realized by the internal elastomer, and the damping characteristics are realized by the sliding support part in addition to the lead plug or high damping, so that the adhesive force in the high shear strain area can be realized by the restraining frame, the intermediate steel plate and the vertical This is complemented by being enclosed with a fixed flange.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a sectional view of a seismic isolation laminated rubber bearing 10 embodying the present invention, and FIG.
0 shows an exploded perspective view of FIG.
A constraining frame 11 formed in a ring shape, and a sheet-like elastomer 12 disposed in a hollow portion 11a of the constraining frame 11
And a plurality of intermediate steel plates 13 to be laminated on the upper and lower surfaces of the restraining frame 11 (in this embodiment, four restraining frames 11 and three intermediate steel plates 13) are laminated to form a laminated rubber bearing body 14
The fixed flanges 15a and 15b are fixed to the upper and lower surfaces of the laminated rubber bearing main body 14, respectively.

A lead plug 16 supported by the fixing flanges 15a and 15b is provided in the center of the plane of the laminated rubber bearing main body 14. As shown in FIG. 3, the sliding surface (contact surface) between the restraint frame 11 and the intermediate steel plate 13 is, for example, a Teflon sheet disposed on one surface and a stainless steel plate on the other surface. It is configured to have a damping characteristic when it is horizontally moved by using it for sliding support.

At this time, the restraining frame 11 surrounding the elastomer 12, the intermediate steel plate 13, and the upper and lower fixing flanges 15a,
By using a constraining material such as a steel plate having a high thermal conductivity for 15b, a function of dissipating a local temperature rise of the elastomer 12 is provided. In this embodiment, the hollow portion 11a of the ring-shaped restraining frame 11 is provided.
The elastomer 12 disposed therein is made of a high-damping rubber, and the inner wall surface 11a of the hollow portion of the restraining frame 11 and the elastomer 12 are not bonded as shown in FIG.
Further, as shown in FIG.
By interposing an O-ring 17 made of rubber or the like between the a and the elastomer 12, the movement at the edge is increased, excessive distortion is prevented, and the durability of the elastomer is improved. It is composed.

With the above configuration, the restraint frame 11
The upper and lower surfaces of the elastomer 12 disposed in the hollow portion 11a of the intermediate steel plate are connected to the intermediate steel plate 13 and the upper and lower fixing flanges 15a and 15a.
b, and is configured to achieve both high vertical rigidity and low lateral rigidity in the vertical load supporting state. It should be noted that the shape of the restraint frame 11 can take various forms such as a ring shape and a rectangular shape in accordance with the shape of the laminated rubber bearing.

Further, as the elastomer used in the present invention, any one of vulcanized rubber, thermoplastic resin and thermosetting resin may be used. As the elastomer, a known composition having high attenuation characteristics can be used. Unvulcanized rubber used as a raw material for vulcanized rubber includes natural rubber (NR), isoprene rubber (IR), styrene / butadiene copolymer rubber (SBR), and natural rubber / styrene / butadiene copolymer rubber (NR). / SBR), natural rubber / butadiene rubber (NR / BR), natural rubber / acrylonitrile butadiene rubber (NR / NBR), and silicone rubber.

Various additives such as a filler, a plasticizer, an antioxidant, a vulcanizing agent, a vulcanization accelerator and a vulcanization aid may be added to the unvulcanized rubber, if necessary. I can do it. Examples of fillers include carbon blacks such as HAF carbon and SAF carbon, etc., examples of plasticizers include aroma oils and waxes, examples of vulcanizing agents include sulfur and zinc white, and examples of vulcanization accelerators include N and N. -Kurokuroshishi-2-benzothiazolesulfenamide (CBS), dibenzothiazyldisulfide (DM) and the like, and as a vulcanization aid, stearic acid and the like can be mentioned.

On the other hand, examples of the thermoplastic resin include ester-based, aodo-based, urethane-based, styrene-based, olefin-based and vinyl chloride-based elastomers, and elastomers in which rubber is dispersed therein. As described above, according to the embodiment of the present invention, the conventional laminated rubber bearing having an integral structure is configured to share the roles of the vertical load resistance and the horizontal movability. In addition to the steel plate 13 and the metal parts of the upper and lower fixed flanges 15a and 15b, the compression stress of the sealed elastomer is used, and the restoring force characteristic is realized by the elastomer 12 made of natural rubber or high damping rubber inside. Is
In addition to the damping characteristics of the lead plug 16 or the elastomer 12, the sliding surface (contact surface) between the restraining frame 11 and the intermediate steel plate 13
Therefore, the adhesive force in the high shear strain region is supplemented by being enclosed by the restraining frame 11, the intermediate steel plate 13, and the upper and lower fixing flanges 15a and 15b.

Further, as another embodiment of the present invention, by forming a cooling channel 18 for circulating the cooling fluid W in the upper and lower fixed flanges 15a and 15b, the cooling channel 18 can be cooled during an earthquake or during normal times. By flowing the cooling fluid W in the flow path 18, it is possible to suppress a rise in temperature and also to have a fire resistance effect against a fire or the like.

[0018]

According to the present invention, the elastomer of the laminated rubber bearing main body is disposed in the hollow portion of the restraining frame as described above, and the restraining frame and the intermediate steel plate can be slid horizontally and alternately laminated. At the same time, the upper and lower surfaces of the elastomer disposed in the hollow portion of the restraint frame are sealed with an intermediate steel plate and upper and lower fixing flanges, and are configured so as to achieve both high vertical rigidity and low lateral rigidity in a vertical load supporting state, By sharing the role of the conventional integrated laminated rubber bearing between vertical load bearing capacity and horizontal mobility, low shear rigid materials that were difficult to use due to the problem of setability can be used, and lateral rigidity can be used. By lowering the height, it is possible to make the natural period of the lightly seismic isolated structure periodic and improve the seismic isolation effect. At the same time, by preventing flammable elastomer from being exposed to the outside, fire And there is an effect that can also be sufficiently deal with.

[Brief description of the drawings]

FIG. 1 is a sectional view of a seismic isolation laminated rubber bearing embodying the present invention.

FIG. 2 is an exploded perspective view of a laminated rubber bearing.

FIG. 3 is an operation explanatory view showing a function of a laminated rubber bearing main body as a sliding bearing.

FIG. 4 is a cross-sectional view of an elastomer disposed in a hollow portion of a restraining frame.

FIG. 5 is a cross-sectional view showing another embodiment of the elastomer provided in the hollow portion of the restraining frame.

FIG. 6 is a cross-sectional view showing another embodiment in which a cooling flow path for circulating a cooling fluid is formed in a fixed flange.

FIGS. 7A and 7B are a plan view and a cross-sectional view of a conventional flange-integrated laminated rubber bearing.

FIGS. 8A and 8B are a plan view and a cross-sectional view of a conventional flanged laminated rubber bearing.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Laminated rubber bearing 11 Restraining frame 11a Hollow part of restraining frame 12 Elastomer 13 Intermediate steel plate 14 Laminated rubber bearing main body 15a, 15b Upper and lower fixed flange 16 Lead plug 17 O-ring 18 Cooling channel W Cooling fluid

Claims (6)

[Claims] 1. A seismic isolation laminated rubber bearing comprising: a laminated rubber bearing body in which a sheet-like elastomer and an intermediate steel plate are alternately laminated; and upper and lower fixed flanges integrally attached to upper and lower surfaces of the laminated rubber bearing body. The elastomer of the laminated rubber bearing main body was disposed in the hollow portion of the restraining frame, and the restraining frame and the intermediate steel plate were slidable in the horizontal direction and alternately laminated, and were disposed in the hollow portion of the restraining frame. The upper and lower surfaces of the elastomer are enclosed by an intermediate steel plate and upper and lower fixing flanges, and have high vertical rigidity in the vertical load supporting state,
A seismic isolation laminated rubber bearing that is configured to achieve both low lateral rigidity. 2. The seismic isolation laminated rubber bearing according to claim 1, wherein a sliding surface between the restraining frame and the intermediate steel plate is a sliding bearing. 3. A flat center portion of the laminated rubber bearing main body,
The seismic isolation laminated rubber bearing according to claim 1 or 2, further comprising a lead plug supported by upper and lower fixing flanges. 4. The seismic isolation laminated rubber bearing according to claim 1, wherein the elastomer disposed in the hollow portion of the restraining frame is a high-damping rubber. 5. The seismic isolation laminated rubber bearing according to claim 1, wherein the inner wall surface of the hollow portion of the restraining frame and the elastomer are not adhered. 6. An O-ring is interposed between the inner wall surface of the hollow portion of the restraining frame and the elastomer.
The seismic isolation laminated rubber bearing according to claim 3, claim 4, or claim 5.