JP2570341B2 - Seismic isolation structure - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a seismic isolation structure in which a plurality of hard plates and soft plates having viscoelastic properties are alternately bonded, and in particular, a seismic isolation structure The present invention relates to a seismic isolation structure having a damping effect as well as an effect.

[Background Art] A structure in which a hard plate such as a steel plate and a soft plate having a viscoelastic property such as rubber are laminated is widely used as a support member which requires vibration-proof properties and vibration-absorbing properties.

The function and effect of such a seismic isolation structure can be achieved by inserting a soft seismic isolation structure having a low shear rigidity in the lateral direction between a rigid building such as concrete and a foundation. By shifting the natural period from the period of the earthquake. Therefore, the seismic isolation design in which the seismic isolation structure is inserted between the building and the base significantly reduces the acceleration received by the building due to the earthquake.

However, since the slow rolling of the building remains as it is, if the amount of the rolling is large, the building may collide with other structures or damage to equipment such as water pipes, gas pipes, and wiring.

Therefore, conventionally, in order to reduce the rolling displacement, a seismic isolation structure and a damper are generally used by being arranged side by side.

In addition, the interior of the seismic isolation structure is hollowed out, lead is buried in this part, and the damping effect is given to the seismic isolation structure using the plastic deformation of lead during an earthquake. It is also considered to have a combination of a damping effect).

[Problems to be Solved by the Invention] However, the method of installing the seismic isolation structure and the damper in parallel complicates the installation work, significantly increases the cost, and cannot be said to be an advantageous method. In a seismic isolation structure, a hard plate such as a steel plate damages lead when a large earthquake deforms the seismic isolation structure,
Furthermore, since the damaged lead damages a soft plate such as rubber, the whole seismic isolation structure is easily broken. Moreover, the damaged lead is easily broken by repeated large deformation.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a seismic isolation structure in which a plurality of hard plates and a plurality of soft plates are bonded to each other. One or more selected from the group consisting of plasticizers, tackifiers, oils, oligomers and lubricants are compounded with rubber, vulcanized and the hysteresis ratio at 25 ° C and 100% tensile deformation is 0.2 to 0.
7 5 Hz, -10 ° C. at 0.01% deformation, the storage elastic modulus E at 30 ° C. _(-10), the ratio E _(-10) of _{E (30) / E (30} ) is such that allowed to have a property of 1.0-3.0 It is composed.

The present inventors combine a seismic isolation effect and a damping effect by imparting a high hysteresis loss to the material constituting the soft plate of the seismic isolation structure as a method of imparting a damping effect to the seismic isolation structure. As a result of repeated investigations, we found the following.

That is, when only the function as a damper is considered, a material having a larger hysteresis loss is preferable. However, as the hysteresis loss increases, the creep increases, and the temperature dependence of the elastic modulus increases.
Undesirable side effects appear as seismic isolation structures supporting buildings. For this reason, the constituent material of the soft plate is required to have a hysteresis loss characteristic within a specific range and a small temperature dependence of the elastic modulus.

The present invention has been completed based on such findings, finding that a material satisfying the above requirements is the most suitable material for a soft plate, which can exhibit both seismic isolation effect and diping effect. It is a thing.

Embodiment An embodiment will be described below with reference to the drawings.

FIG. 1 is a sectional view of a seismic isolation structure 20 according to one embodiment of the present invention. This seismic isolation structure 20 has a flange 4 on the upper and lower surfaces of a laminated structure 13 which is formed by alternately laminating soft plates 11 such as rubber having viscoelastic properties and hard plates 12 having rigidity such as steel plates. , 5 are provided. Thus, the laminated structure 13
Are coated in a coating tank 14.

In the present invention, the soft plate 11 is a filler, a softener, a plasticizer, a tackifier, an oil, an oligomer, and one or more selected from the group consisting of a lubricant, compounded with rubber,
After vulcanization, the hysteresis ratio at 25 ° C and 100% tensile deformation is 0.2 ~
0.75Hz, storage elastic modulus at -10 ℃ and 30 ℃ at 0.01% deformation, E _(-10) , ratio of E _{( 30)} E _(-10) / E ₍₃₀₎ 1.0-3.0 It is made of material.

 Hereinafter, the reasons for the limitation will be described.

Hysteresis Ratio of Material Generally, a loss tangent tan δ value is used as a measure of the hysteresis loss characteristic and the attenuation characteristic of a material. But,
As is well known, tan δ is a quantity that is measured as the response delay of a material to a small amplitude stimulus.
It is unsuitable as a parameter describing the hysteresis loss characteristics of the material used for the base-isolated structure subjected to a large deformation of 0 to 200%.

Therefore, in the present invention, the hysteresis ratio (h ₁₀₀ ) of the material at the time of 25 ° C. and 100% tensile deformation is used as a measure of the loss characteristic.
Note that at a pulling speed of 200 mm / min, h ₁₀₀ is the stress −
In the distortion curve Given by the area ratio of

As described above, h ₁₀₀ is desirably as large as possible for the damper (damping) effect, but this necessarily increases the plastic deformation of the material. Accordingly, the scope of the h ₁₀₀ at 25 ° C. for both characteristics as good, preferably 0.2 ≦ h ₁₀₀ ≦ 0.7 more preferably 0.25 ≦ h ₁₀₀ ≦ 0.65 is 0.3 ≦ h ₁₀₀ ≦ 0.6.

As is well known, the most important influence on seismic isolation characteristics is the vertical spring constant and horizontal spring constant of the seismic isolation structure.
These are directly proportional to the modulus of the material.

On the other hand, looking at the usage of the seismic isolation structure, it is generally used in a state where it is always exposed to the outside air. -10 ℃ in winter,
It is quite possible that the environment will be 30 ° C in summer.
In such a situation, rubber materials and the like show a temperature dependence of the elastic modulus more or less, and tend to become harder at lower temperatures. Further, the greater the amount of material loss, the greater the tendency to exhibit a large temperature dependency.

In the present invention, the temperature dependence of the elastic modulus of the material is small, and the storage elastic modulus E dynamically measured at 5 Hz and 0.01% strain.
Of the value E _(-10) at −10 ° C. and the value E ₍₃₀₎ at 30 ° C. Preferably More preferably It is preferred that

Although the rubber component of the rubber composition of the present invention is not particularly limited, natural rubber (NR), butadiene rubber (BR), ethylene-propylene rubber (EPR, EPDM), butyl rubber (II
R), those containing at least one selected from halogenated butyl rubber and chloroprene rubber as a main component are preferred.

Such a rubber composition of the present invention may contain a compounding agent common to rubber materials such as a vulcanizing agent, a vulcanization accelerator and an antioxidant, if necessary.

As fillers, softeners, plasticizers, tackifiers, oils, oligomers, and lubricants to be added to these rubber components,
Examples include the following:

Fillers: clay, diatomaceous earth, carbon black, silica, talc, barium sulfate, calcium carbonate, magnesium carbonate, metal oxides, mica, graphite, flaky inorganic fillers such as aluminum hydroxide, various metal powders,
Wood chips, glass powder, ceramic powder, granular or powdered solid fillers such as granular or powdered polymers, other various natural or artificial monofilaments, and long fibers (eg, straw, wool, glass fiber, metal fiber, various other types) Fillers for rubber or resin, such as polymer fibers.

The mixing ratio of the filler is preferably 30 to 200 parts by weight based on 100 parts by weight of the rubber.

Softeners: Softeners for various rubbers or resins, such as aromatic, naphthenic and paraffinic.

A preferred compounding ratio of the softener is 5 to 150 parts by weight based on 100 parts by weight of the rubber.

Plasticizers: Various ester-based plasticizers such as phthalic acid ester, phthalic acid mixed ester, aliphatic dibasic acid ester, glycol ester, fatty acid ester, phosphate ester, stearic acid ester, epoxy-based plasticizer, and other plastic plastics Or NBR plasticizers such as phthalate, adipate, sebacate, phosphate, polyether and polyester.

A preferable mixing ratio of the plasticizer is 5 to 150 parts by weight based on 100 parts by weight of the rubber.

Tackifiers: Various tackifiers (tackifiers) such as coumarone resin, coumarone-indene resin, phenol terpene resin, petroleum hydrocarbons, and rosin derivatives.

A preferable mixing ratio of the tackifier is 1 to 50 parts by weight based on 100 parts by weight of the rubber.

Oligomer: Clau ether, fluorinated oligomer, polybutene, xylene resin, chlorinated rubber, polyethylene wax, petroleum resin, rosin ester rubber, polyalkylene glycol diacrylate, liquid rubber (polybutadiene, styrene-butadiene rubber, butadiene-acrylonitrile rubber, polychloroprene Various oligomers such as silicone-based oligomers and poly-α-olefins.

A preferred compounding ratio of the oligomer is 5 to 100 parts by weight based on 100 parts by weight of the rubber.

Lubricants: hydrocarbon lubricants such as paraffin and wax, fatty acid lubricants such as higher fatty acids and oxy fatty acids, fatty acid amide lubricants such as fatty acid amides and alkylene bis fatty acid amides, fatty acid lower alcohol esters, fatty acid polyhydric alcohol esters, and fatty acid poly Ester lubricants such as glycol esters, fatty alcohols, polyhydric alcohols,
Various lubricants such as alcohol-based lubricants such as polyglycol and polyglycerol, metal soaps, and mixed lubricants.

The preferred compounding ratio of the lubricant is 1 to 100 parts by weight of rubber.
5050 parts by weight.

In the present invention, as the material of the hard plate 12, metal, ceramics, plastics, FRP, polyurethane, wood, paper plate, slate plate, decorative plate and the like can be used, and among them, steel plate is preferable.

Further, the shape of the hard plate and the soft plate may be a circle, a square, or a polygon such as a pentagon or a hexagon.

In order to bond such a hard plate and a soft plate, an adhesive or co-vulcanization may be used.

The seismic isolation structure 20 of the embodiment shown in FIG.
The outer surfaces of the portions in contact with the flanges 4 and 5 are curved surfaces whose inner surfaces are warped in an arc-like or arc-like shape with a vertical cross section so that the cross-sectional area gradually increases toward the flanges.

If the radius of the curved surface formed in a portion in contact with the flanges 4 and 5 of the laminated structure 13 is too small, the effect of reducing the local distortion due to the provision of the curved surface is low and conversely large. Too much makes it very difficult to manufacture seismic isolation rubber.

Accordingly, as shown in FIG. 2 which is an enlarged view of the VII portion in FIG.
For the thickness h of the hard plate, the radius L is preferably More preferably Above all It is desirable to be as follows.

In this embodiment, the arc shape or the arc-like shape of the curved surface is not limited to the arc shape as shown in FIG. 2 but may be any shape similar to this and having an effect of reducing local stress. For example, shapes such as a combination of one or a plurality of straight lines as shown in FIGS. 3A and 3B and a combination of a straight line and an arc as shown in FIG. 3C are exemplified.

In the embodiment shown in FIG. 1, the side end surface of the hard plate 12 is formed to have an arc-shaped or arc-like cross-sectional shape which bulges outward, and the outer peripheral portion of the hard plate is also covered with a covering rubber. Thus, the hard plate 11 was configured to be embedded in the coating layer 14.

In this case, the radius of the arc of the cross section of the bulge formed on the side end face of the hard plate 12 is the value of r shown in FIG. 2, preferably 0.1R ≦ r, more preferably 0.3R ≦ r. It is desirable that 0.5R ≦ r. (However, 1R is an arc with a radius of 1 mm.) The arc shape or arc-like shape of the bulging portion is as follows.
In addition to the above-mentioned arcs, those which act like an arc to reduce local stress, for example, as shown in FIGS. 4 (a) and 4 (b),
Composed of a plurality of linear cut surfaces, or FIG. 4 (c)
And various arc-like shapes such as a combination of a linear cut surface and an arc.

As in the present embodiment, by making the edges of the hard plate 12 smooth by a combination of curves or straight lines, it is possible to greatly reduce the stress or strain generated in the soft plate 11 in contact with the edges. Becomes possible.

As in the embodiment shown in FIG. 1, the edge portion of the hard plate 12 is bulged into an arc shape or an arc-like shape and covered with rubber having an appropriate thickness as described above, so that a local portion near the flange of the seismic isolation rubber is provided. The distortion can be further reduced, the distortion can be averaged as a whole of the seismic isolation structure, and the absolute value of the local distortion can be reduced.

In this case, the thickness T of the coating layer 14 is preferably 1 to 30 mm, preferably 2 to 20 mm, and particularly preferably 3 to 15 mm. However, when other performance such as fire resistance is particularly required for the seismic isolation structure, the thickness of the coating layer can be more than 30 mm.

Since the seismic isolation structure is constantly exposed to the outside air during use, it is subject to long-term deterioration by air, humidity, ozone, ultraviolet light, radiation for nuclear power, and sea breeze at the seaside. Further, since the building is supported, it is constantly subjected to a compressive load, and a considerable tensile stress is applied to the surface portion of the rubber layer even in a normal state. In addition, during a large earthquake, the rubber layer is locally subjected to a tensile strain of 100 to 200%. The deterioration further progresses due to such tensile stress and tensile strain.

For this reason, it is preferable to coat the outer peripheral edge portions of the hard plate and the soft plate of the seismic isolation structure with a coating layer of a rubber material having excellent weather resistance.

However, when EPDM or chloroprene rubber is used as the rubber constituting the soft plate, a coating layer for improving the weather resistance is not necessarily required because the rubber itself is excellent in the weather resistance.

Examples of the rubber material of the coating layer for improving the weather resistance include butyl rubber, acrylic rubber, polyurethane, silicone rubber, fluorine rubber, polysulfide rubber, ethylene propylene rubber (ERP and EPDM), hypalone, chlorinated polyethylene, and ethylene acetate. Vinyl rubber, epichlorohydrin rubber, chloroprene rubber, and the like. Of these,
Particularly, butyl rubber, polyurethane, ethylene propylene rubber, hypalone, chlorinated polyethylene, ethylene vinyl acetate rubber, and chloroprene rubber are effective from the viewpoint of weather resistance. Further, in consideration of the adhesiveness with the rubber constituting the soft plate, butyl rubber, ethylene propylene rubber,
Chloroprene rubber is preferred.

These rubber materials may be used alone or as a blend of two or more. Further, it may be blended with a commercially available rubber, for example, a natural rubber, an isoprene rubber, a styrene-butadiene rubber, a butadiene rubber, a nitrile rubber or the like to improve elongation and other physical properties. Further, these rubber materials include various fillers, anti-aging agents, plasticizers, softeners,
A general compounding agent may be mixed with a rubber material such as oil. In particular, the cyclopentadiene or dicyclopentadiene resin is 5 to 50 parts by weight based on 100 parts by weight of the rubber material containing ethylene propylene rubber as a main component, and further, rosin is used for 2 to 3 parts.
By adding 0 parts by weight, the breaking characteristics, adhesion to metals, and the like are greatly improved, which is extremely advantageous.

The cyclopentadiene resin or dicyclopentadiene resin blended with the rubber containing ethylene propylene rubber as a main component is a petroleum resin mainly composed of cyclopentadiene or dicyclopentadiene, and is used together with cyclopentadiene or dicyclopentadiene. It refers to a copolymer with a polymerizable olefinic hydrocarbon or a polymer of cyclopentadiene and / or dicyclopentadiene. It is necessary that these resins contain at least 30% by weight, preferably at least 50% by weight of the resin weight, based on the weight of cyclopentadiene, dicyclopentadiene or a mixture of cyclopentadiene and dicyclopentadiene. Is done.

In addition, as olefin hydrocarbons which can be co-polymerized with cyclopentadiene or dicyclopentadiene, 1-butene, 2-butene, isobutylene, 1-pentene, 2-pentene, 2-methyl-1-butene, 3-methyl- Olefinic hydrocarbons such as 1-butene and 2-methyl-2-butene; butadiene, isoprene, 3-methylbutadiene 1,
And divinyl hydrocarbons such as styrene, α-methylstyrene, vinyltoluene and the like, which are free from cyclopentadiene or dicyclopentadiene in the presence of a suitable catalyst. It can be shared by Delkraft reaction or the like.

In the present invention, such a cyclopentadiene resin or dicyclopentadiene resin is required to have a softening point (ring-reaction point) in consideration of its molecular weight and reactivity of a double bond for the physical properties of the vulcanized rubber. Formula JIS K-5902) is 50 to 200
C. and a bromine number (ASTM D-1158-57T) in the range of 40 to 150 are preferred.

The compounding amount of these cyclopentadiene resins and / or dicyclopentadiene resins is 5 to 50 parts by weight based on 100 parts by weight of a rubber containing ethylene propylene rubber as a main component.
Preferably it is 10 to 40 parts by weight.

On the other hand, as the rosin derivative, a main component is a mixture of abietic acid, pimaric acid and a carboxylic acid having a structure similar thereto, and various rosin-based esters, polymerized rosin, hydrogenated rosin, cured rosin, hyrosin, zinc resinate, modified Rosin and the like.

The amount of such a rosin derivative is 2 to 30 parts by weight based on 100 parts by weight of a rubber mainly composed of ethylene propylene rubber.
Parts by weight.

The ethylene propylene rubber as a rubber component includes ethylene propylene diene rubber (EPDM) containing a diene as the third component, ethylene propylene rubber (EPR) containing no third component, and oil-extended ethylene propylene diene rubber, oil-extended. EPR.

General purpose rubbers such as NR, BR, and SBR may be added to these ethylene propylene rubbers for the purpose of improving workability and the like, if necessary.

Various vulcanization accelerators can be used in this rubber composition. As the vulcanization accelerator, thiazole type, guanidine type, thiuram type, dithiocarbamate type and the like are preferable, and in particular, N-cyclohexyl-2-benzothiazolesulfenamide, dibenzothiazyl disulfide,
Tetramethylthiuram monosulfide, 2-mercaptobenzothiazole, 2-mercaptobenzothiazole cyclohexylamine salt, tetra-2-ethylhexylthiuram disulfide, di-2-ethylhexyldithiocarbamic acid zinc salt, diphenylguanidine are preferred, and N-cyclohexyl is particularly preferred. -2-Benzothiazolesulfenamide and diphenylguanidine are optimal. The amount of the vulcanization accelerator is preferably in the range of 0.5 to 5 parts by weight.

Further, the rubber composition contains various fillers, an antioxidant,
A general compounding agent for a rubber material such as a plasticizer, a softener, and an oil may be contained.

In the present invention, basically, the coating layer of the bulging portion of the hard plate 12 is made of the special rubber having excellent weather resistance, and the thickness thereof is made to match the thickness of the coating layer. If preferable, but not possible due to manufacturing or other reasons, the thickness of the special rubber 13, that is, the thickness t in FIG. 2, does not necessarily have to match the thickness of the coating layer. In that case,
The special rubber thickness t is 1 to 20 mm, preferably 2 to 20 mm, particularly preferably 2 to 15 mm. It is important that such special rubber is firmly bonded to the soft plate 11, the hard plate 12, and the flanges 4 and 5, but the bonding is a rubber material of the soft plate 11 (hereinafter sometimes referred to as “inner rubber”). .) And special rubber 13 are simultaneously vulcanized and bonded.

b. A two-stage vulcanization bonding method in which only the internal rubber is vulcanized first, and then the special rubber is vulcanized and bonded.

c A method in which the internal rubber and special rubber are separately vulcanized and then bonded with an adhesive.

Etc. can be easily performed. If the adhesion between the internal rubber and the special rubber is poor, a third rubber layer having good adhesion to both may be interposed between the two. Further, an additive for improving adhesion may be blended with the internal rubber and / or the special rubber.

By the way, even when the local distortion near the flange is reduced by the configuration as shown in FIG. 1, the local distortion of other parts of the seismic isolation structure is increased, and the maximum local distortion is reduced as a whole. Not being able to happen generally.

Therefore, in order to reduce the local strain near the flange, average the local strain of the entire seismic isolation rubber, and reduce the absolute value of the local strain in each part, the following (i) laminated structure has been described. The shape of the curved surface formed on the part of the body that contacts the flange.

(Ii) The shape of the bulge formed on the side end face of the hard plate. (Iii) The balance of each element must be maintained in order to sufficiently bring out the improvement effect due to the thickness of the rubber covering the outer surface of the laminated structure. More important than anything else. Thus, the balance can be kept good only by the FEM calculation for large deformation developed by the present inventors.

By the way, as described above, the seismic isolation structure undergoes large shear deformation due to the shaking of the building at the time of the earthquake. Particularly, in the surface layer of the soft plate on the flange mounting side of the laminated structure, extremely large local strain is generated due to the shear deformation, which causes damage and breakage of the seismic isolation structure. Since the distortion is caused by bending deformation of the hard plate on the flange mounting side, in order to more reliably prevent this, in the present invention, the bending rigidity of the hard plate on the flange mounting side is compared with that on the center side. Make it higher.

II Increase the tensile stress of the soft plate on the flange mounting side compared to that on the center side.

It is preferable to adopt at least one of the configurations.

As described above, by imparting non-uniformity to the bending rigidity of each hard plate and / or the tensile stress of the soft plate, bending deformation of each hard plate is less likely to occur, resulting from bending deformation of the hard plate near the flange. The occurrence of local distortion is reduced, and problems such as damage and breakage of the seismic isolation rubber due to local distortion are more reliably eliminated.

In the case of the configuration I, as shown in FIG. 5, the hard plates are S ₁ , S ₂ , S ₃ ... S _M ( _SM is a hard plate located at the center) from the flange mounting side, and each is at 25 ° C. The bending stiffness at E _S1 , E
_S2, when the E _S3 ...... E _SM, flexural rigidity E _S1 of hard plate S ₁ whereas flexural rigidity E _SM of hard plate S _M, Preferably More preferably So that

The flexural rigidity E _S2 of the hard plate S ₂ is the flexural rigidity E _SM rigid plate S _M
Against Preferably It is desirable that

Further, the bending rigidity E _S3 of the hard plate S ₃
It may be higher than the bending stiffness E _{SM of M.}

In this case, the bending rigidity E _S1 , E of the hard plates S ₁ , S ₂ , S ₃ ... S _M
S2 , E _S3 …… E _{SM is changed} to E _S1 ≧ E _S2 ≧ E _S3 ≧ …… ≧ E _SM (However,
Except when E _S1 = E _S2 = E _S3 =... = E _SM . ), Or randomly set so that E _S1 , E _S3 and E _S7 (the bending rigidity of the _seventh hard plate _S7 from the flange side) are larger than E _SM. good. In the present invention, it is only necessary that the bending rigidity on the flange side is higher than the bending rigidity of the hard plate on the center side, and the bending rigidity of each hard plate is estimated to be added to the seismic isolation structure. Is appropriately set depending on the direction and degree of

There is no particular limitation on the method of increasing the bending rigidity of the hard plate on the flange side than that on the center side, but a hard plate of the same material as the center side increases the plate thickness, and is different from the center side. The method using a hard plate made of a material having higher bending rigidity is appropriate.

For, generally the thickness of the same material of the plate is a bending stiffness 2 ^triple doubles, plate thickness having a flexural rigidity in need is readily determined by calculation.

In the case of configuration II, place the soft plate from the flange mounting side.
R ₁ , R ₂ , R ₃ …… R _M (R _M is the soft plate in the center), and the tensile stress (Modulus 1
00), and the _{E R1, E R2, E R3} ...... E RM, tensile stress E _R1 of the soft plate R ₁ whereas stress E _RM of soft plate R _M, Preferably More preferably It is preferred that

The tensile stress E _R2 soft plate R ₂ whereas tensile stress E _RM soft plate R _M Preferably It is preferred that

Further, the tensile stress E _R3 of the soft plate R ₃
It may be higher than the _M of tensile stress E _RM.

In this case, the soft plate _{R 1, R 2, R 3} ...... R M tensile stress
E _R1 , E _R2 , E _R3 ... _ERM is _replaced by E _R1 ≧ E _R2 ≧ E _R3 ≧... ≧ E _RM (except when E _R1 = E _R2 = E _R3 =... = E _RM ) Or E _R1 , E _R3 , and E _R7 (the tensile stress of the _seventh soft plate _R7 from the flange side) may be set to be larger than _ERM .

The method for increasing the tensile stress of the soft plate on the flange side higher than that on the center side is not particularly limited, but the amount of filler and the like is increased by using a base material of the same quality as the center side.

A soft plate made of a material having a high tensile stress different from the center side is used.

The method is appropriate.

By adopting the configuration of I and / or II, occurrence of local strain due to bending deformation of the hard plate near the flange is reduced, and damage and breakage of the base-isolated structure due to local strain are prevented,
It is very advantageous. The laminated structure may have one of the configurations I and II, or may have a combination of both, but by having both the configurations I and II, the rigid plate on the flange mounting side Since bending deformation is less likely to occur, local distortion due to bending deformation of the hard plate is more reliably reduced.

In the present invention, in order to impart a higher seismic isolation effect to the seismic isolation structure, as shown in FIG. 6, a cylindrical space is provided at the center of the laminated structure 13 including the soft plate 11 and the hard plate 12. Alternatively, the space may be filled with a material 15 having high loss characteristics.

In this case, examples of the high loss characteristic material 15 to be filled include unvulcanized rubber and / or vulcanized rubber filled with a filler as necessary, resin or resin FRP containing a viscous material, a plasticizer, or the like. Can be

Rubber materials for unvulcanized rubber or vulcanized rubber include ethylene propylene rubber (EPR, EPDM) and nitrile rubber (NB
R), butyl rubber, halogenated butyl rubber, chloroprene rubber (CR), natural rubber (NR), isoprene rubber (I
R), styrene-butadiene rubber (SBR), butadiene rubber (BR), acrylic rubber, polyurethane, silicone rubber, fluorine rubber, polysulfide gum, hypalone, ethylene vinyl acetate rubber, epichlorohydrin rubber, and the like are suitable. These rubber materials may be used alone or as a blend of two or more.

As the filler to be blended, for example, clay, diatomaceous earth carbon black, silica, talc, barium sulfate, calcium carbonate, magnesium carbonate, metal oxide,
Scale-like inorganic fillers such as mica, graphite, and aluminum hydroxide, various metal powders, wood chips, glass powders, ceramic powders, granular or powdery solid fillers such as granular or powdery polymers, and other various natural or artificial fillers Single fibers and long fibers (for example, straw, wool, glass fiber, metal fiber, various other polymer fibers, and the like) are exemplified.

As the resin, polystyrene, polyethylene, polypropylene, ABS, polyvinyl chloride, polymethyl methacrylate, polycarbonate, polyacetal, nylon,
Thermoplastics such as chlorinated polyethers, polytetrafluoroethylene, acetylcellulose, ethylcellulose, etc., and thermosetting plastics such as phenolic resins, urea resins, unsaturated polyesters, epoxy resins, alkyd resins, and melamine resins are suitable. I have.

Depending on the purpose, these plastics may be used as the plastic itself, or may be used by blending an appropriate viscous substance, a plasticizer, and an oligomer (low molecular weight polymer).

In this case, as the viscous material, a mineral oil softener such as an aroma oil, a naphthene oil, or a paraffin oil;
Vegetable oil-based softeners such as castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, peanut oil, rosin, and pine oil; low molecular weight oils such as silicone oil are preferred.

It is also possible to increase the viscosity of the viscous body by adding a sticking agent, thereby further improving the damping effect. Examples of the tackifier include a coumarone resin, a phenol, a terpene resin, a petroleum hydrocarbon resin, a rosin derivative, and the like.

Other effective examples of the viscous material include plasticized plastics obtained by mixing a plasticizer, an oil filler, and the like into a thermoplastic rubber described later as a high hysteresis rubber material, and an agar-like inorganic or organic gel.

Plasticizers include phthalic acid, isophthalic acid, adipic acid, tetrahydrophthalic acid, sebacic acid, azelaic acid, maleic acid, fumaric acid, trimellitic acid, citric acid, itaconic acid, oleic acid, ricinoleic acid, stearic acid, phosphorus Various acid derivatives such as acid and sulfonic acid; various derivatives of glycol, glycerin, paraffin, and epoxy;
And a polymerization plasticizer. Also, bitumen and the like are suitable. These may be used alone or as a blend of two or more.

Examples of the oligomer include crown ether, fluorine-containing oligomer, polybutene, xylene resin, chlorinated rubber, polyethylene wax, petroleum resin, rosin ester rubber, polyalkylene glycol diacrylate, liquid rubber (polybutadiene, styrene-butadiene rubber, butadiene-acrylonitrile rubber, Polychloroprene), silicone-based oligomers, poly-α-olefins, and the like.

As the FRP, FRP or the like obtained by reinforcing the above rubber or plastic with various fibers or fillers is also suitable.

The material to be filled in the space does not necessarily need to be composed of one kind of material, and may be made by combining some of the above materials.

When the internal space is filled with such a high loss characteristic material, the size of the space to be formed is determined by the ratio of l ₁ to l ₂ shown in FIG. It is preferable that

Such a seismic isolation structure of the present invention, in addition to the seismic isolation function,
It has characteristics such as vibration isolation (anti-vibration, vibration suppression), and has the following features.

Large local strains such as the maximum local strain are not concentrated near the flange, but are widely and evenly distributed throughout the seismic isolation structure.

The maximum local strain generated in the base isolation structure has been greatly reduced.

Thus, problems such as damage and breakage of the base-isolated structure due to local distortion are solved.

As described above, the seismic isolation structure of the present invention has extremely excellent durability since the occurrence of local strain is extremely effectively reduced, so that damage and breakage of the seismic isolation structure due to local distortion are reduced. Becomes In addition, since it can be fixed to the building and the foundation via the flange, it is possible to stably support the building and the like.

When special rubber is used for the surface of the laminated structure of the seismic isolation structure, the durability and safety of the seismic isolation structure can be further improved.

By the way, such a seismic isolation structure is provided with a cylindrical space in the center of the laminated structure composed of a soft plate and a hard plate in order to exhibit a higher damping effect together with the seismic isolation effect.
It is preferable to arrange a damper in this space. In this case, the diameter of the cylindrical space (internal diameter) and D _1,
The diameter of the laminated structure (outer diameter) is taken as D _0, is preferable to the ratio of D ₁ and D ₀ is made to be D ₁ / D ₀ ≦ 0.7 particularly D ₁ / D ₀ ≦ 0.5 is there.

As a material of the damper, a resin obtained by filling an unvulcanized rubber and / or a vulcanized rubber with a filler as required, a resin or a resin containing a viscous material or a plasticizer, etc. Viscoelastic materials such as FRP are preferable. It is preferable to have the physical properties of (a) and (b).

(A) At 25 ° C and 50% tensile deformation (tension speed 200mm / min)
Has a hysteresis ratio (h ₅₀ ) of 0.2 or more, especially 0.3 or more.

(B) Storage elastic modulus (E) dynamically measured at a frequency of 5 Hz, a strain of 0.01% and a temperature of 25 ° C. is 1 ≦ E ≦ 2 × 10 ⁴ (Kg / cm ² )
In particular, it must be in the range of 5 ≦ E ≦ 1 × 10 ⁴ (Kg / cm ² ).

By arranging a specific viscoelastic substance having excellent hysteresis characteristics as a damper, it was possible to obtain a seismic isolation structure with extremely high damping in a wide range from small deformation to large deformation.

Such a seismic isolation structure of the present invention was realized for the first time in the research on the present invention because quantitative analysis of local strain generated in the seismic isolation structure during deformation became possible. It should be clearly distinguished from the seismic isolation structure, and its academic and industrial significance is extremely large.

 Hereinafter, the present invention will be described in more detail with reference to experimental examples.

Experimental Example 1 The NR rubber compounded rubber sheet (2 mm thick) and the NR rubber whose both sides were destroyed by 4 mm thick FPDM rubber were subjected to 40% elongation at 50%, respectively.
The sample was left in ozone at 100 ° C. and 100 pphm, and the time until crack generation was determined.

As a result, the NR rubber cracked within 1 hour, whereas the EPDM rubber-coated NR rubber did not crack even after 2000 hours.

From the results of Experimental Example 1, it is clear that by coating ordinary rubber with rubber having excellent weather resistance, deterioration of the internal rubber is almost completely prevented.

Experimental Example 2 Vulcanized rubber test pieces were produced from the rubber compositions having the compositions shown in Table 1 below, and their physical properties were examined. The results are shown in Table 1.

From Table 1, it can be seen that the rubber compositions of Nos. 1 to 4 according to the present invention have good loss characteristics, temperature dependency, rubber breaking characteristics, and characteristics of elastic modulus, and are very well balanced as a whole. It is clear that

Experimental Example 3 Using the rubber compositions of Nos. 1, 2, 4, and 5 in Table 1 as soft plate materials, a seismic isolation structure of the present invention as shown in FIG.
The damping effect was investigated.

The specifications and measurement conditions of each part of the seismic isolation structure are as follows.

Specifications of seismic isolation structure Size of each part in Fig. 8 a = 435mm b = 445mm c = 172mm Shape of d part = r value shown in Fig. 2 r = 1mm Sectional arc shape Shape of e part = 2 The values of L, h, and k shown in the figure are Curved surface with a circular arc cross section Soft plate: Rubber of Table 1, No. 1, 2, 4 or 5 20mm thick (k) x
7 layers (= 154mm) Hard plate: Iron plate 3mm thickness (h) x 6 layers (= 18mm) Measurement conditions Temperature: Room temperature (25 ° C) Vibration: 0.5Hz swing (See Fig. 9) Vertical load: 30Kg / cm ² Horizontal shear strain: 65% The damping effect is equivalent to the equivalent viscous damping coefficient (Equivalent Viscous Damping Coefficie) generally used in the fields of construction and machinery as a value indicating the magnitude of the damping effect of laminated rubber.
(nt).

 The results are shown in Table 2.

Table 2 shows that the seismic isolation structure of the present invention has a remarkably excellent seismic isolation effect.

[Effects of the Invention] As described above in detail, the seismic isolation structure of the present invention has a damper effect in addition to the seismic isolation effect, so that the shaking at the time of the occurrence of an earthquake is absorbed by the seismic isolation structure and transmitted to the building. The degree of is reduced. Therefore, even in the event of a major earthquake,
It is possible to prevent the building from colliding with other structures and to break down equipment such as water pipes, gas pipes, and wiring.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a seismic isolation structure according to an embodiment of the present invention,
FIG. 2 is an enlarged view of part II of FIG. Fig. 3 (a)-
(C) is a diagram showing an example of a curved surface near the flange, and FIGS. 4 (a) to (c) are diagrams showing an example of a bulging portion on a side end surface of a hard plate. FIGS. 5 and 6 are cross-sectional views of a laminated structure according to another embodiment of the present invention. Fig. 7 shows the stress of the material.
It is a graph which shows a distortion curve. FIG. 8 is a schematic diagram showing the seismic isolation structure manufactured in Experimental Example 3, and FIG. 9 is a schematic diagram showing a swinging state performed in Experimental Example 3. 11: Soft plate, 12: Hard plate, 13: Laminated structure, 14: Coating layer, 20: Seismic isolation structure.

Claims (1)

(57) [Claims] In a seismic isolation structure in which a plurality of hard plates having rigidity and soft plates having viscoelastic properties are alternately bonded, a material constituting the soft plate is a filler, a softener, a plasticizer, One or two or more selected from the group consisting of an agent, a tackifier, an oil, an oligomer, and a lubricant are compounded into rubber and vulcanized to give the following physical properties. Seismic isolation structure. Hysteresis ratio at 25 ° C, 100% tensile deformation is 0.2 ~
0.75Hz, storage modulus E _(-10) at -10 ° C and 30 ° C at 0.01% deformation, ratio of E _(-10) , E ₍₃₀₎ E _(-10) / E ₍₃₀₎ is 1.0 to 3.0