JPH09177368A - Vibration isolator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration isolation structure having an effect on an earthquake and traffic vibrations and having excellent vibration-isolation performance not subject to an, effect by a wind shaking, etc., at the normal time and superior durability. SOLUTION: This vibration isolator 10 is installed among a foundation and structures 14 on the land. The vibration isolator 10 has a vibration isolation structure 16, in which a composite laminate, in which a plurality of hard plates 24 having rigidity and soft plates 26 having viscoelastic properties are alternately laminated respectively, is installed between an upper face plate 20 and a connecting steel plate 22 and a columnar hollow section is formed into the composite laminate and the hollow section is filled with hard particulate matters 30 such as glass beads, and a vibration isolation pad 18 being mounted between the vibration isolation structure 16 and an underside plate 36 and having viscoelastic properties.

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, and more particularly to a seismic isolation device which can be suitably used for light loads such as detached houses which are easily affected by wind sway, traffic vibration and the like. .

[0002]

2. Description of the Related Art Conventionally, seismic isolation structures in which a plurality of rigid hard plates such as steel plates and soft plates such as rubber having viscoelastic properties are alternately laminated are used for middle and low-rise buildings. It is widely used as a rubber support piece for seismic isolation devices such as bridges and bridges. An elastic body such as rubber constituting a soft plate of such a seismic isolation structure is generally designed to have the following spring characteristics. That is, the lateral spring constant KH of an elastic body such as rubber
, And the mounted mass is M, the horizontal natural frequency fH is designed to satisfy the following conditions.

[0003]

[Equation 1]

Since the natural frequency fH is determined by the ratio of the weight of a building or bridge to the lateral spring constant KH of an elastic body such as rubber, the seismic isolation device is flexible even if the building or bridge has a large loading weight M. As the elastic body forming the plate, a material having a high spring rigidity or a highly elastic material is generally used. If this is applied to a light load such as a detached house, since the detached house has a small loading weight M, the material of the soft plate needs to have a low spring rigidity and a low elasticity. Although such a seismic isolation device is effective against earthquakes, it suffers wind sway and traffic vibrations. In order to prevent these, it is common to use a plastic material such as lead in the laminated portion of the base isolation structure.

Such a seismic isolation structure using lead in combination, for example, has both high elasticity at low strain and low elasticity at high strain, and high damping properties, so it is effective for earthquakes and wind sway. can do. However, in the case of a large earthquake with a shear strain of 200%, the seismic isolation effect can be exhibited, but due to high shear strain and strain stress, the plastic material such as lead used inside is greatly plastically deformed or cut and fractured. Since it is not possible to replace only the seismic isolation device when used in a building, it has a higher durability that can be used continuously even after it is subjected to a vibration such as a large earthquake. A seismic device was requested. Also,
The above seismic isolation structure alone was not sufficient to prevent traffic vibrations.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional techniques, and has high performance even when the seismic isolation device is applied to a lightweight object such as a detached house, It is an object of the present invention to provide a seismic isolation device which is free from plastic deformation and breakage and has excellent durability and which can prevent traffic vibration.

[0007]

A seismic isolation device according to the present invention is a seismic isolation device installed between a foundation and an upper body, and includes a rigid hard plate and a viscous plate between upper and lower face plates. Providing a composite laminate in which a plurality of soft plates having elastic properties are alternately laminated, and a columnar hollow portion that penetrates the composite laminate is provided inside the composite laminate, and the hollow portion It has a viscoelastic property installed between the seismic isolation structure filled with hard granular material, one face plate of the seismic isolation structure, and the face plate fixed to either the foundation or the upper body. The anti-vibration pad described above is provided.

Further, in the seismic isolation apparatus of the present invention, when a cylindrical column having a hollow portion in the center is used for this composite laminate, the diameter of the composite laminate in plan view is D, and the plane of the hollow portion is It is characterized in that D and d have a relationship satisfying the following equation, where d is the diameter by visual observation.

0.6 ≧ d / D ≧ 0.15 Furthermore, the average particle diameter of the hard granules to be filled in the hollow portion is 0.1 mm to 30 mm, and the hardness of the hard granules is Mohs hardness. It is characterized by being 2 or more.

The seismic isolation device of the present invention is installed between a foundation and an upper body, and includes a rigid hard plate and a soft plate having viscoelastic properties between a lower plate and an upper plate attached to the foundation. , A seismic isolation structure composed of a laminated composite in which a plurality of layers are alternately laminated and a hard granular material filled in the hollow part of the seismic isolation structure and face plate are used to prevent wind sway and seismic isolation. The anti-vibration pad having the viscoelastic property provided between the parts can exert the effect of anti-vibration against traffic vibration and wind sway.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a seismic isolation structure used in the seismic isolation device of the present invention will be described. Materials used for soft plates that have viscoelastic properties that make up the seismic isolation structure,
50% modulus is 1.5 to 3 kgf / cm ² , 25 ° C
The dynamic shear modulus G at 1.5 to 3 kgf / cm
^It has the property of ² and has a 50% modulus of 1.
5 to 2.5 kgf / cm ² , dynamic shear modulus G is 1.
It is preferably 5 to 2.5 kgf / cm ² .

The 50% modulus and the dynamic shear modulus G of various materials are, for example, JIS K6301, K6394.
It can be measured according to.

Here, as the material having viscoelastic properties, organic materials such as thermoplastic rubber, urethane rubber, various vulcanized rubbers, unvulcanized rubbers, slightly crosslinked rubbers, plastics and the like, foams thereof, Various materials such as inorganic materials such as asphalt and clay, and mixed materials thereof having the above viscoelastic properties can be used.

These materials are molded into a flat plate and used as a soft plate. The shape of the soft plate is not particularly limited, but since the seismic isolation apparatus of the present invention has a columnar hollow portion, it is necessary to have a hollow portion at the center.
Usually, a so-called columnar one having a hollow portion in the center is used, and each soft plate has a donut disc shape. The thickness of the soft plate is not particularly limited and can be selected depending on the material used and the desired seismic isolation performance, but generally 1 to 4
A thickness of about mm is used.

These materials may be used alone or as a mixture of plural kinds, and may be formed of a uniform material as a whole. However, a high damping material is used for the inner portion and a creep performance is used for the outer portion. You may use it in combination of 2 or more types with a good and soft material.

Further, as the hard plate constituting the seismic isolation structure, metal, ceramics, plastics, FR
Various materials having required rigidity, such as P, polyurethane, wood, paper board, slate board, decorative board, etc., can be used. Here, the required rigidity largely depends on design conditions, but means rigidity that does not easily cause a buckling phenomenon when subjected to shear deformation.

There is no particular limitation on the thickness and shape of the hard plate,
The thickness can be selected according to the material used and the desired seismic isolation performance, but the thickness is generally about 0.5 to 2 mm. The shape is arbitrary as well as the soft plate to be laminated, except that it has a hollow portion at the center, but usually the same shape as the soft plate used together is used.

The soft plate and the hard plate are alternately laminated in a plurality of stages to form a composite laminate. The shape, area, and thickness of each of the soft plate and the hard plate differ depending on the seismic isolation performance required as described above, but normally, as described above, the composite laminate exhibits a columnar shape having a hollow portion, It is widely used that both the hard plate and the hard plate have the same donut shape and have the same surface area.

In these seismic isolation structures, it is common to use a hard plate having rigidity and a doughnut-shaped plate as a soft plate having viscoelastic properties. In that case,
When the diameter of the seismic isolation structure in plan view is D and the diameter of the hollow portion of the seismic isolation structure in plan view is d, D and d are
It is preferable that the following formula is satisfied.

0.6 ≧ d / D ≧ 0.15 When d / D exceeds 0.6, the balance between the spring rigidity of the composite laminate existing around and the frictional force between the granular materials filled in the hollow portion. There is a risk that it will not return to its original position after it has been severely damaged due to collapse, an earthquake, etc., and d / D is 0.15
If it is less than the above range, the effect of the frictional force is small, and the desired damping effect cannot be obtained. Even when the composite laminate to be used is not cylindrical having a hollow portion, it is preferable that the area ratio between the composite laminate and the hollow portion is in a range derived from the above equation.

Specifically, for example, the above D is 50 to 30.
It is preferably 0 mm and d is about 7.5 to 180 mm.

In order to impart weather resistance to the seismic isolation apparatus of the present invention, the outside of the seismic isolation structure may be covered with a material having excellent weather resistance. As this coating material, for example, butyl rubber,
Acrylic rubber, polyurethane, silicone rubber, fluorine rubber, polysulfide rubber, ethylene propylene rubber (ERP and EPDM), chlorosulfonated polyethylene, chlorinated polyethylene, ethylene vinyl acetate rubber, chloroprene rubber, and the like can be used. These materials may be used alone or as a blend of two or more. Further, it may be blended with natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, nitrile rubber and the like.

The hard granular material to be filled in the columnar hollow portion of the seismic isolation structure can prevent excessive deformation of the seismic isolation structure due to the frictional force of the granular materials by compressing and filling. If so, there is no particular limitation, but a material formed of a material having a Mohs hardness of 2 or more is preferable. As a suitable material, for example, copper (Mohs hardness:
2), iron (Mohs hardness: 4), sand for sandblasting (Mohs hardness: 9), glass (Mohs hardness: 6), quartz (Mohs hardness: 7), and the like, and further fiber reinforced having the above-mentioned preferable hardness. Plastics, various ceramics, etc. can also be used.

The size of the granules is preferably in the range of 0.1 to 30 mm. If the size is less than 0.1 mm, sufficient stress cannot be applied during filling, and if the size exceeds 30 mm, the size of the granules is the same. This is not preferable because the contact area becomes small and it is difficult to obtain a desired frictional force in either case.

Specific examples of this hard granular material include glass beads, metal balls such as iron balls and copper balls, sand, quartz powder, and Al ₂ O.
Sand blasting sand containing ₃ as a main component.

The shape of the granular material is not particularly limited as long as it has the above-mentioned size, and is spherical, spindle-shaped,
It may be any of irregular shapes and the like, and the surface of the granular material may be smooth or may have fine irregularities. Also, those having a shape close to a sphere having an aspect ratio of about 3 or less are preferably used.

When filling the hollow part of the seismic isolation structure with these hard granular materials, it is necessary to perform the closest packing by tapping or the like, and further to enclose so that a stress is applied by a lid or the like. Is preferred. Since the frictional force between the hard particles closely packed in the hollow portion contributes to the damping effect, the desired damping effect cannot be obtained in the filled state having a space where the hard particles can freely vibrate with each other, which is preferable. Absent.

The vibration-proof pad in the seismic isolation device of the present invention is
A pad made of a material having a viscoelastic property, which is installed between one face plate of the seismic isolation structure and a face plate fixed to either a foundation or an upper body. ,
It may be located between the upper body and the base isolation structure or between the base isolation structure and the foundation.

The anti-vibration pad has rubber pads installed on both sides between the face plate attached to the upper body or the foundation and one face plate of the seismic isolation structure, or an iron plate is attached to both sides of the rubber pad by an adhesive agent. It is provided by attaching a rubber pad with an iron plate adhered by a method such as vulcanization adhesion. The rubber pad may have a single layer of rubber or a laminated structure of rubber and a hard plate. In the case of mounting, it is preferable from the viewpoint of mounting strength to form a recess on the face plate side so that the vibration-proof pad can be fitted and to mount it via the key plate.

The shape of the vibration-proof pad used in the seismic isolation apparatus of the present invention may be columnar or prismatic, or may be donut-shaped with the central portion of the columnar or prismatic hollowed out. The size and thickness are not particularly limited and can be appropriately selected depending on the required seismic isolation performance, but normally, those having a thickness of about 5 to 20 mm can be suitably used.

As the material having a viscoelastic property which constitutes the vibration damping pad, the same material as that of the soft plate used for the seismic isolation structure can be preferably used. In particular, those having a 50% modulus of 1.5 to ² kgf / cm ² and a dynamic shear modulus G at 25 ° C. of 1.5 to ² kgf / cm ² are preferable.

The structure of the present invention is a composite laminated body in which a plurality of rigid hard plates and soft plates having viscoelastic properties are alternately laminated between upper and lower face plates of the seismic isolation device. This is provided with a vibration-isolating pad and a seismic isolation structure in which a columnar hollow portion is filled with hard granular material.

The face plates on both sides of the anti-vibration pad are connected by bolts with a space for vibration, and in the event of an earthquake, the intermediate face plate and the lower face plate are fixed by the bolts, and the seismic isolation structure is constructed. Only the particles are subjected to shear deformation, but due to the friction between the particle surfaces of the hard granules that are closely packed in the hollow part that moves according to the shear deformation, the vibrations are effectively damped, and a so-called plastic deformation is applied to the laminated structure. It does not cause enough damage. Further, the vibration-damping pad having a viscoelastic property provided between the seismic isolation structure and the face plate effectively damps traffic vibration. For this reason, the seismic isolation effect is not lost in one earthquake, and it has a durable seismic isolation effect, and is not only excellent for large deformations such as earthquakes, but also for small vibrations such as traffic vibrations. It demonstrates its performance.

The seismic isolation device of the present invention is characterized by selecting the characteristics of the size of soft and hard plates, the number of laminated sheets, the volume of the hollow part, the granular material to be filled, the size and material of the anti-vibration rubber, etc.
It is possible to obtain a seismic isolation device that exhibits excellent seismic isolation performance for relatively lightweight (lightly loaded) objects such as detached houses. Here, the light load means a surface pressure of less than 50 kgf / cm ² , further a surface pressure of 30 kgf / cm ² or less, and more preferably a surface pressure of 2
It means 0 kgf / cm ² or less.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings. Table 1 collectively shows the conditions and test results of Examples and Comparative Examples.

(Embodiment 1) FIG. 1 is a sectional view of a seismic isolation device 10 according to Embodiment 1 of the present invention. The seismic isolation device 10 is located between the upper object (building) 12 and the foundation 14,
6 and the anti-vibration pad 18 are laminated in the vertical direction. The seismic isolation structure 16 portion includes a hard plate 24 between a top plate 20 attached to the upper body (building) 12 and a face plate (hereinafter, referred to as a connecting steel plate) 22 on the lower side of the seismic isolation structure 16.
As outer diameter 250mm, inner diameter 46mm, thickness 1.6m
30 sheets of m steel plate are used, and the soft plate 26 has a 50% modulus of 1.9 kgf / cm ² and a tensile strength of 70 k.
A rubber material having gf / cm ² and an elongation at break of 700% was used, and 31 layers of the soft plate 18 (one sheet having a thickness of 1.6 mm) were used. The hollow portion 28 provided in the central portion of the laminated body of the seismic isolation structure 16 was filled with the maximum amount of glass beads (spherical) 30 having a diameter of 1 mm that can be filled while tapping, and the upper portion thereof was screwed with M46. The lid 32 was filled and sealed so that the glass beads 30 therein were in a compressed state by applying a compressive force with a torque of 5 kgm. Furthermore, the seismic isolation structure 16 was constructed by covering the outer periphery of this laminated body with an outer cover rubber 34 made of a natural rubber-based rubber material.

The vibration-proof pad 18 has a diameter of 240 m.
m, thickness 10 mm, 50% modulus 2.0 kgf / cm ² , tensile strength 100 kg
It was molded using a rubber material having f / cm ² and an elongation at break of 700%.

A concave portion having a diameter of 241 mm and a depth of 7 mm is provided in a portion of the lower surface plate 36 fixed to the connecting steel plate 22 and the foundation 14 in contact with the vibration damping pad 18, and the vibration damping pad 18 is fitted therein. Diameter 240mm, thickness 1
The 0 mm key plates 38 and 40 were vulcanized and adhered.

The connecting steel plate 22 is connected to the lower plate 36 by bolts 42 of M20 in order to prevent large deformation of the vibration-proof pad 18 when a large shearing force is applied. In order to secure a room for vibration, the drill hole of the connecting steel plate 22 has an inner diameter of 26 mm, and a gap with the bolt 42 is provided around 3 mm.
The nut 44 screwed to the bolt 42 is for preventing the locking phenomenon at the time of an earthquake,
It is tightened to the extent that it touches. To prevent the bolt 42 and the connecting steel plate 22 from directly colliding with each other during an earthquake or wind sway,
A rubber cover 46 having a thickness of 1 mm is wound around the bolt 42 so that collision noise is not generated.

The seismic isolation device 10 has a shear rigidity (G) of 2.5 kgf / cm ² when a vibration is applied with a sine wave of a load of 10 t and a frequency f of 0.2 Hz and a shear strain of 100%. , Tan δ was 0.35.

Further, the shear strain of the vibration-proof pad 18 itself is 10%.
The shear rigidity (G) was 2.0 kgf / cm ² , and from this result, Example 1 which is the seismic isolation device of the present invention.
Has a natural vibration of 1.5 Hz and is confirmed to have sufficient seismic isolation performance for vibrations of 3 Hz or higher.

[0042]

As is apparent from the above description, the seismic isolation device of the present invention has high performance and is free from plastic deformation and cutting failure when applied to a light weight object such as a detached house. It was possible to obtain a seismic isolation device that has an excellent damping effect even for small vibrations such as traffic vibrations and that has excellent durability.

[Brief description of the drawings]

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

[Explanation of symbols]

 10: Seismic isolation device 16: Seismic isolation structure 18: Anti-vibration pad 20: Top plate 22: Connecting steel plate 24: Hard plate 26: Soft plate 30: Glass beads (hard granular material) 32: Lid 34: Outer rubber 36: Bottom plate 38, 40: Key plate 42: Bolt 44: Nut 46: Rubber cover of bolt

Claims (3)

[Claims] 1. A seismic isolation device installed between a foundation and an upper body, wherein a plurality of rigid hard plates and a plurality of soft plates having viscoelastic properties are provided between upper and lower face plates, respectively. And a seismic isolation structure in which a column-shaped hollow portion penetrating the composite laminate is provided inside the composite laminate, and the hollow laminate is filled with hard particulate matter. A vibration-isolating pad having a viscoelastic property, which is installed between one face plate of the seismic isolation structure and a face plate fixed to either the foundation or the upper body. Seismic isolation device. 2. The composite laminate has a columnar shape having a hollow portion in the center, where D is the diameter of the composite laminate in plan view and D is the diameter of the hollow portion in plan view.
2. The seismic isolation device according to claim 1, wherein and satisfy the following formula. 0.6 ≧ d / D ≧ 0.15 3. The average particle size of the hard granules is 0.1 mm.
The seismic isolation device according to claim 1 or 2, wherein the hardness of the hard granular material is -30 mm and the hardness of the hard granular material is 2 or more in Mohs' hardness.