JPH09177367A - Base insulation structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain excellent base insulation properties and to ensure durability by packing a hard granular material most closely in a columnar hollow part provided inside a composite laminated body prepared by laminating a plurality of hard plates and soft plates alternately between upper and lower face plates, and by sealing it with a cover. SOLUTION: A plurality of hard plates 16 having rigidity and a plurality of soft plates 18 having viscoelastic properties are laminated alternately between an upper face plate 12 and a lower face plate 14, whereby a composite laminated body is prepared. Next, a columnar hollow part 20 penetrating the laminated body is disposed inside the laminated body and a hard granular material 22 such as glass beads is packed in the hollow part 20. In this case, the ratio in the size between the laminated body and the hollow part 20 is made 0.6>=d/D>=0.15 when the diameter of the former and that of the latter in a plan view are denoted by D and (d) respectively. Besides, the average particle size of the hard granular material 22 is made 0.1-30mm and the Mohs hardness thereof 2 or above. By the friction between the grain surfaces of the granular material 22 being packed in the hollow part 20 and moving in accordance with the shear deformation of a base insulation structure at the time of an earthquake or the like, vibration is damped effectively and a durable base insulation. effect can be given to the structure, according to this constitution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation device, which can be suitably used not only for a large building but also for a light load of a detached house which is particularly susceptible to wind sway or the like. It relates to the seismic isolation structure used for.

[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. In addition, a structure in which a plastic material such as lead is used together in the laminated portion of the base isolation structure is generally used.

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 up to 200%, the effect of seismic isolation can be exhibited, but due to the 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 structure when it is used in buildings, it has higher durability that can be used continuously even after it is subjected to vibration such as a large earthquake. A seismic isolation structure was requested.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional techniques, and the seismic isolation device is not only used for heavy objects such as buildings and bridges but also lightweight for detached houses. An object of the present invention is to provide a seismic isolation structure that has high performance even when applied to an object and has excellent durability without plastic deformation or cutting fracture.

[0007]

The seismic isolation structure of the present invention comprises:
A rigid hard plate and a soft plate having viscoelastic properties between the upper and lower face plates, each having a plurality of columns, each having a columnar shape penetrating the composite laminate at the center of the composite laminate. It is characterized in that a hollow portion is provided and hard particles are filled therein.

Further, in the seismic isolation structure 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, It is characterized in that D and d have a relationship satisfying the following equation, where d is a diameter in a plan view.

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.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The material used for the soft plate having the viscoelasticity of the seismic isolation structure of the present invention is a material having a 50% modulus of 1.5 to 10 kgf / cm ² and a dynamic shear at 25 ° C. An elastic modulus G indicates a property of 1.5 to 10 kgf / cm ² , and a 50% modulus is 2 to 8 kgf.
/ Cm ² , dynamic shear modulus G is ^{2 to} 8 kgf / cm ²
Are preferred.

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, examples of the material having viscoelastic properties include organic materials such as thermoplastic rubber, urethane rubber, various vulcanized rubbers, unvulcanized rubbers, slightly crosslinked rubbers, and plastics, 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 formed 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 structure 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 in general,
When it is used for heavy objects, it has a thickness of 5 to 10 mm, and when it is used for lightweight objects, it has a thickness of about 1 to 4 mm.

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

Further, as the hard plate in the seismic isolation structure of the present invention, 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 means a rigidity of a patent with shear deformation or a buckling phenomenon, although it varies greatly depending on design conditions.

There is no particular limitation on the thickness and shape of the hard plate,
It can be selected depending on the material used and the desired seismic isolation performance, but its thickness is generally
2 to 4 mm, 0.5 to 2 mm when used for lightweight items
It is of a moderate thickness. 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.

A plurality of layers of the soft plate and the hard plate are alternately laminated 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 rigid hard plate and a doughnut-shaped soft plate having viscoelastic properties. In that case,
When the diameter of the soft plate in plan view is D and the diameter of the hollow portion of the soft plate in plan view is d, it is preferable that D and d satisfy the following formula.

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 of the granular materials filled in the hollow portion. There is a risk that it will not return to its original position after being severely deformed due to crushing, earthquakes, etc. If d / D is less than 0.15, the effect of frictional force is small and the desired damping effect cannot be obtained. Therefore, neither is preferable. 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, when used in a heavy object, D is 500 to 1500 mm and d is 75 to 900.
mm, when used for lightweight objects, the D is 50 to 300 m
It is preferable that m and d are about 7.5 to 180 mm.

In order to impart weather resistance to the seismic isolation structure of the present invention, the outside of the seismic isolation structure may be coated 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.

In the seismic isolation structure of the present invention, the hard granular material to be filled in the columnar hollow portion can be compressed and filled to prevent excessive deformation of the seismic isolation structure due to the frictional force between the granular materials. The material is not particularly limited as long as it is a material, but a material formed of a material having a Mohs hardness of 2 or more is preferable. Examples of suitable materials include 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.
Fiber reinforced plastics having various preferable hardnesses, various ceramics, etc. can also be used.

The size of the granules is preferably in the range of 0.1 to 30 mm. If it is less than 0.1 mm, sufficient stress cannot be applied at the time of filling, and if it 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 it is spherical, spindle-shaped,
It may be an irregular shape or the like, and the surface of the granular material may be smooth or may have fine irregularities, but from the viewpoint of the deformation mitigating effect and frictional force, it is more preferable than the flat shape. Also, those having a shape close to a sphere with an aspect ratio of about 3 or less are preferably used.

When filling the hollow portion 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 seismic isolation structure of the present invention can be selected from heavy objects such as bridges and buildings by selecting the size of the soft and hard plates, the number of laminated sheets, the volume of the hollow part, and the characteristics of the granular material to be filled.
For relatively lightweight (light load) objects such as detached houses,
It is possible to obtain a seismic isolation structure having excellent seismic isolation performance.
Here, the light load means a surface pressure of less than 50 kgf / cm ² ,
Furthermore, the surface pressure is 30 kgf / cm ² or less, and more preferably the surface pressure is 20 kgf / cm ² or less.

The structure of the present invention is a composite laminate in which a plurality of rigid hard plates and soft plates having viscoelastic properties are alternately laminated between the upper and lower face plates of the seismic isolation structure. And a column-shaped hollow portion penetrating the composite laminate is provided inside the composite laminate, and a hard granular material is filled therein.

During an earthquake or the like, a large deformation is applied to the seismic isolation structure, but due to the friction between the particle surfaces of the hard granules that are most closely packed in the hollow portion that moves according to the shear deformation,
The vibration is effectively damped, and the laminated structure is not damaged so much as to cause so-called plastic deformation. Therefore, the seismic isolation effect is not lost in one earthquake, and has a durable seismic isolation effect.

[0030]

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 shows a sectional view of a seismic isolation structure 10 according to Embodiment 1 of the present invention. In the seismic isolation structure 10 shown in FIG. 1, a top plate 12 (iron plate) and a bottom plate 1
4 outside diameter as the rigid plate 16 between the (iron plate) 160 mm, an inner diameter of 30 mm, 20 sheets steel plate having a thickness of 1 mm, as the soft sheet 18, 50% modulus of 1.9kgf / cm ^2, a tensile strength of 70 kgf / cm ^2, A soft plate 18 (thickness 1.6 mm per sheet) made of a rubber material whose elongation at break is 700%
21 layers were used. The hollow portion 20 provided in the central portion of the laminated body of the seismic isolation structure 10 was filled with the maximum amount of glass beads (spherical) 22 having a diameter of 1 mm that could be filled while tapping, and the upper portion thereof was threaded with M30. Glass beads 2 inside by screwing the lid 24 with a torque of 1 kgm
It was filled and sealed so that 2 was in a compressed state. Further, the outer periphery of this laminated body was covered with the outer rubber 26 made of a natural rubber-based rubber material to obtain a seismic isolation structure, which was Example 1.

A load of 3 t and a frequency f =
Shear rigidity (G) and tan δ when a vibration was applied at a shear strain of 100% at 0.2 Hz were measured. The results are shown in Table 1 below.

A seismic isolation structure was produced in the same manner as in Example 1 except that the hollow portion 20 of this laminated body was not filled with the glass beads 22, and Comparative Example 1 was obtained. The seismic isolation structure of Comparative Example 1 was evaluated in the same manner as in Example 1, and the results are shown in Table 1 below.

[0034]

[Table 1]

As is apparent from Table 1, the damping effect of Example 1 which is the seismic isolation structure of the present invention is remarkably improved as compared with the seismic isolation structure of Comparative Example 1 in which the hollow portion is not filled with glass beads. Was.

Further, looking at this result, the shear rigidity (G)
It was confirmed that the numerical values of 2.5 kgf / cm ² and tan δ of 0.37 are, for example, sufficient levels for a seismic isolation structure for detached houses.

(Second Embodiment) FIG. 2 is a sectional view of a seismic isolation structure 28 according to a second embodiment of the present invention. In the seismic isolation structure 28 shown in FIG. 2, the upper plate 12 (iron plate) and the lower plate 1
Between 4 (iron plates), 20 hard steel plates 16 having an outer diameter of 160 mm, an inner diameter of 60 mm and a thickness of 1 mm, and a soft plate 18 having a 50% modulus of 6.0 kgf / cm ² and a tensile strength of 200 kgf / cm ² , 650% elongation at break
21 layers of soft plates (one sheet having a thickness of 1.6 mm) were used. Glass beads (spherical) having a diameter of 1 mm are provided in the hollow portion 20 provided at the center of the laminated body of the seismic isolation structure 28.
22 is filled while tapping the maximum amount that can be filled, a nylon plate 30 having a thickness of 1.5 mm is arranged as a cushioning material on the uppermost portion, and the upper lid 32 is fixed by bolting it from above. Glass beads 22 inside
Was filled and sealed so that the powder was in a compressed state. Further, the outer circumference of this laminated body is covered with a rubber 2 using a natural rubber type rubber material.
A seismic isolation structure was obtained by coating with No.6, and this was taken as Example 1.

Shear rigidity (G) and tan δ when a vibration was applied to this seismic isolation structure 28 at a load of 10 t and a frequency f = 0.2 Hz and a shear strain of 100% were measured. The results are shown in Table 2 below.
It was shown to.

A seismic isolation structure was prepared as Comparative Example 1 in the same manner as in Example 2 except that the hollow portion of this laminate was not filled with glass beads. The seismic isolation structure of Comparative Example 2 was evaluated in the same manner as in Example 2, and the results are shown in Table 2 below.

[0040]

[Table 2]

As is clear from Table 2, the damping effect of Example 2 which is the seismic isolation structure of the present invention is remarkably improved as compared with the seismic isolation structure of Comparative Example 2 in which the hollow portion is not filled with glass beads. Was.

[0042]

As is apparent from the above description, the seismic isolation structure of the present invention has high performance when applied to not only heavy objects such as buildings and bridges but also light objects such as detached houses. In addition, it was possible to obtain a seismic isolation structure with excellent durability and without plastic deformation or cutting fracture.

[Brief description of the drawings]

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

FIG. 2 is a sectional view of a seismic isolation structure according to a second embodiment of the present invention.

[Explanation of symbols]

 10: Seismic isolation structure 12: Top plate (iron plate) 14: Bottom plate (iron plate) 16: Hard plate 18: Soft plate 20: Columnar hollow part 22: Glass beads (hard granular material) 24: Lid 26: Outside Rubberized 28: Seismic isolation structure 30: Nylon plate (cushion material) 32: Upper pig

Claims (3)

[Claims] 1. A plurality of hard plates having rigidity and a plurality of soft plates having viscoelastic properties are provided between the upper and lower face plates, respectively.
A seismic isolation structure having a composite laminated body that is alternately laminated, and having a columnar hollow portion that penetrates the composite laminated body inside, wherein the columnar hollow portion is filled with hard particulate matter. A seismic isolation structure characterized by the above. 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 structure 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 structure according to claim 1 or 2, wherein the seismic isolation structure has a hardness of -30 mm and a hardness of the hard granular material of 2 or more in Mohs' hardness.