JPH09217520A - Base isolation structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base isolation structure by alternately laminating a plurality of hard plates and soft plates with viscoelastic property, and laminating a plurality of friction plates, made of polymeric material of the specific value or less in the modulus of elasticity, in a hole piercing a center part. SOLUTION: Steel plates 1 of 250mm in outer diameter, 50mm in inner diameter and 1.6mm in thickness, and soft plates 2 made of rubber material of 2.3kgf/ cm<2> in 50% modulus, 90kgf/cm<2> in tensile strength, 760% in rupture time elongation, the modulus of shearing elasticity G=1.9kgf/cm<2> in shearing stress 200%, and 2.5mm in thickness with tan δ of 0.11 are placed between an upper face plate 3 and a lower face plate 4 made of iron plates. Polyamide friction plates 6 of 1.6mm in thickness and 49.8mm in outer diameter are further filled in a center through hole, and an external thread 8 is pushed into an internal thread 7, provided at the upper face plate 8, so as to apply compressive force of 5-150kg/cm<2> to the friction plates 6. The elastic modulus of the friction plates 6 is to be 1.5×10<5> kgf/cm<2> or less. A base isolation structure prevented from the generation of irreversible deformation can thereby be obtained.

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 used for a seismic isolation device suitable for a light load such as a detached house which is easily affected by wind sway and for general buildings. It is about.

[0002]

2. Description of the Related Art Conventionally, a seismic isolation structure in which a plurality of rigid hard plates, such as steel plates, and a plurality of soft plates, such as rubber, which also have viscoelastic properties, are alternately laminated Widely used as a rubber support piece for seismic isolation devices such as low-rise buildings 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, with the lateral spring constant KH of an elastic body such as rubber and the mounting mass M, the natural frequency fH in the horizontal direction is designed to satisfy the following conditions. fH = (1 / 2π) √ (KH / M) = 0.5 (Hz) This 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. Therefore, as the elastic body that constitutes the soft plate of the seismic isolation device having a large mounting mass M such as a building or a bridge, a material having a large 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 mounted mass M of the detached house is small, the material of the soft plate has a small spring rigidity,
Low elasticity was needed. In addition, a damper (energy absorbing device) is used to quickly suppress the shaking caused by the earthquake.
It was common to use them together. As one of the dampers, there is proposed in Japanese Patent Laid-Open No. 62-141330, etc., in which a through hole is provided in a composite laminated body of seismic isolation structures, and a plurality of friction plates are laminated in the hole. Was there.

[0003]

However, not all friction plates can exhibit these characteristics. For example, when a metal plate is used as the friction plate, the surroundings of the friction plate at the time of high shear strain, that is, when an earthquake occurs There is a problem in that the friction plate causes irreversible deformation due to contact with the composite laminate, and the function as a seismic isolation structure cannot be exhibited. The present invention has been made in view of such a conventional technique, and provides a seismic isolation structure that is highly effective against earthquakes and wind sway and does not cause irreversible deformation.

[0004]

According to the present invention, a plurality of hard plates having rigidity and soft plates having viscoelastic properties are alternately laminated between upper and lower face plates of a seismic isolation structure. A hole penetrating the composite laminate is provided inside the composite laminate, and a plurality of friction plates are laminated in the holes, and the elastic modulus of the friction plate is 1.5 × 10 ⁵ Kgf / cm ² The following problems were solved by using the following polymeric materials.

BEST MODE FOR CARRYING OUT THE INVENTION

The material used for the soft plate of the seismic isolation structure of the present invention has a 50% modulus of 1.0 to 10 Kgf.
/ Cm ² is preferable, more preferably 1.0 to 7 Kgf / cm ² , and further 1.0 to 5 Kgf.
/ Cm ² is preferably used. That is, thermoplastic rubber, urethane rubber, various vulcanized rubbers, unvulcanized rubbers, slightly cross-linked rubbers, organic materials such as plastics, foams thereof, inorganic materials such as asphalt and clay, mixed materials thereof, and the like. The thing of can be used. These materials may be used alone, or two or more kinds may be used in combination, such as a high damping material for the inner part and a material having good creep performance and soft material for the outer part. Further, as the hard plate in the present invention, metal, ceramics, plastics, FRP, polyurethane, wood, paper plate, slate plate,
Various materials having a required rigidity such as a decorative plate can be used.

In order to impart weather resistance to the seismic isolation structure used in the seismic isolation device of the present invention, the outside of the seismic isolation structure may be covered with a material having excellent weather resistance. As the clothing material, for example, butyl rubber, acrylic rubber, polyurethane, silicone rubber, fluorine rubber, polysulfide rubber, ethylene propylene rubber (ERP and EPDM), hypalon, chlorinated polyethylene, ethylene vinyl acetate rubber, chloroprene rubber, etc. 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 friction plate used in the present invention has an elastic modulus of 1.
It is a polymer material of 5 × 10 ⁵ Kgf / cm ² or less. The polymer material is preferably 1.1 × 10 ⁵ Kgf / cm ² or less, and more preferably 8.5 × 10 ⁴ Kgf / cm ² or less. For example, one example of the elastic modulus when using diallyl phthalate for the friction plate is 1.1 × 10 ⁵ Kgf / cm.
^2. One example of the elastic modulus when glass fiber reinforced (30%) 66 nylon is used is 8.5 × 10 ⁴ Kgf / cm
An example of the elastic modulus when using ² , 66 nylon alone is
It is 2.9 × 10 ⁴ Kgf / cm ² .

The material of the friction plate used in the present invention is limited to polymer materials. Examples of the polymer material include thermoplastics such as polyamide (nylon), polyethylene, polypropylene, polystyrene, glass fiber reinforced polystyrene, poly-P-xylene, polyvinyl acetate, polyacrylate, polymethacrylate, polyvinyl chloride, and polyvinyl chloride. Vinylidene chloride, fluoroplastics, polyacrylonitrile, polyvinyl ethers, polyvinyl ketones, polyethers, polycarbonates, thermoplastic polyesters, diene plastics, polyurethane plastics, aromatic polyamides, polyphenylenes, silicones and thermosetting plastics (eg unsaturated Polyester resin) or the like can be used. These plastics may be used alone or mixed with a plasticizer, a filler, and a reinforcing material such as glass fiber or carbon fiber. Further, these plastics may be used alone or in combination of plural kinds.

The structure of the present invention is a composite laminate in which a plurality of rigid hard plates and a plurality of soft plates having viscoelastic properties are alternately laminated between upper and lower face plates of a seismic isolation structure. A hole is provided inside and a plurality of friction plates are laminated in the hole. At the time of an earthquake, this friction plate moves in accordance with the shear deformation of the base isolation structure, and draws a hysteresis loop as shown in FIG. FIG. 5 shows a hysteresis loop (strain-force) when vibration of 200% strain is applied to a seismic isolation structure loaded with a load of 8 tons with a sine wave of f = 0.2 Hz. The hysteresis loop of the seismic isolation structure of the present invention must be a positive gradient loop as shown in FIG. For example, when a stainless plate is used as the friction plate, the hysteresis loop at that time is as shown in FIG. 8, and a negative gradient portion is formed in the returning deformation process. This is because the metal friction plate causes irreversible deformation due to contact with the soft and hard plates of the surrounding composite laminate during shear deformation. In other words, this irreversible deformation part is caught by the adjacent hard plate, and a negative gradient is generated in the hysteresis loop, and at the same time, a discontinuous impact sound is generated and the soft plate is damaged, which may cause the seismic isolation structure to break. It can happen.

The thickness t of the friction plate of the present invention is as _follows :
It is preferable that the thickness is not more than the sheet thickness t _R. Further, the diameter d of the friction plate at this time is d ≧ 10 (h / (H−t) where H is the height of the composite laminate and h is the total thickness of the soft plate.
_Masatsu )) t _masatsu is preferred. That is, the hard plate 1
When the thickness of the plate is t _S and the number of hard plates is n, H = (n + 1) t _R + nt _S h = (n + 1) t _R At this time, the number of friction plates between the upper and lower face plates is m. _{Assuming one} sheet, H = mt _Masatsu . Since the overlapping portion of the friction plates when the shear strain is 200% is preferably 80% or more of the diameter d of the friction plates, (2h / (m−1)) ≦ 0.2d d ≧ 10 (h / (m− 1)) = 10 (h / ((H / t _mass ) -1)) = 10 (h / (H-t _mass )) t _mass . More preferably, the overlapping portion of the friction plates at a shear strain of 200% is preferably 90% or more of the diameter d of the friction plates, and d ≧ 20 (h / ( _{Ht mass} )) t _mass . The diameter d of the friction plate is preferably 0.1 ≦ (d / D) ≦ 0.8, where D is the diameter of the hard plate. More preferably, 0.1 ≦ (d / D) ≦ 0.6. When d / D exceeds 0.8, the frictional force becomes too large, the balance with the spring rigidity of the seismic isolation structure is lost, and the restoring force is impaired. If d / D is less than 0.1, the purpose cannot be achieved because sufficient damping cannot be obtained.

The friction plate of the present invention is preferably enclosed in a hole penetrating the composite laminate with a pushing force of 5 to 150 Kgf / cm ² . More preferably 5 to 100 Kgf / c
m ² and further 10 to 60 Kgf / cm ² . If the pressure to be filled exceeds 150 Kgf / cm ² , the seismic isolation structure will be greatly stretched in the vertical direction. Even if the initial amount of sinking during use, that is, during loading, is taken into consideration, 150
The limit is Kgf / cm ² . In addition, pushing force 5 Kgf /
If it is less than cm ² , the compressive force is insufficient, and sufficient frictional force cannot be obtained as a seismic isolation structure.

The seismic isolation structure of the present invention is used for a general building with a surface pressure of 150 Kgf / cm ² or less and 50 Kgf / cm ² or more. Also, for light loads, it is suitable as a light load seismic isolation structure with a surface pressure of less than 50 Kgf / cm ² , further less than 30 Kgf / cm ^{2, and} more preferably less than 20 Kgf / cm ^2. Used.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings.

[Embodiment 1] FIG. 1 is a sectional view of a seismic isolation structure according to Embodiment 1 of the present invention. In the seismic isolation structure shown in FIG. 1, the hard plate 1 has an outer diameter of 250 mm, an inner diameter of 50 mm, and a thickness of 1.6 m between the upper plate 3 (iron plate) and the lower plate 4 (iron plate).
30 steel plates of m (partly omitted in the figure), the soft plate 2,
50% Modulus 2.3Kgf / cm ² , Tensile Strength 90
Kgf / cm ² , elongation at break 760%, shear modulus at shear strain 200% G = 1.9 Kgf / cm ² , and tan δ used rubber material of 0.11, outer diameter 250 mm, inner diameter 50
mm, and one soft plate having a thickness of 2.5 mm was used in 31 layers (partly omitted in the figure). As the friction plate 6, 99 nylon plates having a thickness of 1.5 mm and an outer diameter of 49.8 mm (partly omitted in the figure) are provided in the through hole in the center so that no gap is formed between the friction plates. Enclosed. Natural rubber was used as the outer rubber 5. A compression screw was applied to the friction plate by cutting an M48 female screw 7 on the upper surface plate 3 and pressing an M48 male screw 8 into the upper surface plate 3. The torque at that time is 5K
The gm and pushing force were 25 Kgf / cm ² . Load 8
shearing strain of 20 at frequency f = 0.2 Hz
FIG. 5 shows a hysteresis loop when vibrating at 0%. From this, it can be seen that Example 1 is a stable hysteresis loop having no negative gradient. That is, by using a polymer material (nylon) for the friction plate, an ideal hysteresis loop is obtained without permanent deformation.

Second Embodiment FIG. 2 is a sectional view of a seismic isolation structure according to a second embodiment of the present invention. In the seismic isolation structure shown in FIG. 2, the hard plate 1 has an outer diameter of 250 mm, an inner diameter of 50 mm, and a thickness of 1.6 m between the upper plate 3 (iron plate) and the lower plate 4 (iron plate).
30 steel plates of m (partly omitted in the figure), the soft plate 2,
50% Modulus 2.3Kgf / cm ² , Tensile Strength 90
Kgf / cm ² , elongation at break 760%, shear modulus at shear strain 200% G = 1.9 Kgf / cm ² , and tan δ used rubber material of 0.11, outer diameter 250 mm, inner diameter 50
mm, and one soft plate having a thickness of 2.5 mm was used in 31 layers (partly omitted in the figure). The same rubber as in Example 1 was used as the outer rubber 5. As the friction plate 6, 99 nylon plates having a thickness of 1.5 mm and an outer diameter of 49.8 mm (partly omitted in the figure) are provided in the through hole in the center so that no gap is formed between the friction plates. After loading, the disc spring 9 was placed on the friction plate 6 and sealed. The pushing force at that time is 25 kg
f / cm ² . Load a load of 8 ton and frequency f
FIG. 6 shows a hysteresis loop when vibrating with a shear strain of 200% at 0.2 Hz. From this, it can be seen that Example 2 is a stable hysteresis loop having no negative gradient.

Third Embodiment FIG. 3 is a sectional view of a seismic isolation structure according to a third embodiment of the present invention. In the seismic isolation structure shown in FIG. 3, the hard plate 1 has an outer diameter of 250 mm, an inner diameter of 50 mm, and a thickness of 1.6 m between the upper surface plate 3 (iron plate) and the lower surface plate 4 (iron plate).
30 steel plates of m (partly omitted in the figure), the soft plate 2,
50% Modulus 2.3Kgf / cm ² , Tensile Strength 90
Kgf / cm ² , elongation at break 760%, shear modulus at shear strain 200% G = 1.9 Kgf / cm ² , and tan δ used rubber material of 0.11, outer diameter 250 mm, inner diameter 50
mm, and one soft plate having a thickness of 2.5 mm was used in 31 layers (partly omitted in the figure). The same rubber as in Example 1 was used as the outer rubber 5. As a friction plate 6, 93 pieces of nylon plates having a thickness of 1.5 mm and an outer diameter of 49.8 mm were loaded into the through hole in the center so that there was no gap between the friction plates and the packing was placed on the plate. As a result, a rubber plate 10 having a JIS hardness of 60 ° and a thickness of 10 mm was enclosed in a compression groove. The pushing force at this time was 5 Kg / fcm ² . Load 8 to
n, load, f = 0.2Hz, shear strain 200%
FIG. 7 shows a hysteresis loop when vibrated by. According to this, the zero slope portion appears in the central portion of the hysteresis loop, but there is no negative slope portion.
Although it is inferior to the second embodiment, it functions as a seismic isolation structure.

[Comparative Example 1] FIG. 4 shows a sectional view of a seismic isolation structure according to Comparative Example 1 of the present invention. In the seismic isolation structure shown in FIG. 4, the hard plate 1 has an outer diameter of 250 mm, an inner diameter of 50 mm, and a thickness of 1.6 m between the upper plate 3 (iron plate) and the lower plate 4 (iron plate).
30 steel plates of m (partly omitted in the figure), the soft plate 2,
50% Modulus 2.3Kgf / cm ² , Tensile Strength 90
Kgf / cm ² , elongation at break 760%, shear modulus at shear strain 200% G = 1.9 Kgf / cm ² , and tan δ used rubber material of 0.11, outer diameter 250 mm, inner diameter 50
mm, and one soft plate having a thickness of 2.5 mm was used in 31 layers (partly omitted in the figure). The same rubber as in Example 1 was used as the outer rubber 5. As the friction plate 6, 99 stainless steel plates (SUS304) having a thickness of 1.5 mm and an outer diameter of 49.8 mm (partly omitted in the figure) are provided in the central penetrating hole, and a gap is provided between the friction plates. Enclosed so that it cannot be done. A compression screw was applied to the friction plate by cutting an M48 female screw 7 on the upper surface plate 3 and pressing an M48 male screw 8 into the upper surface plate 3. The torque at that time is 5 kg · m, and the pushing force is 25
Kgf / cm ² . FIG. 8 shows a hysteresis loop when a load of 8 tons is applied and vibration is performed at a vibration frequency f = 0.2 Hz and a shear strain of 200%. According to this, the loop waveform is disturbed from the middle of the return deformation, and shows a sharp negative gradient before returning to the origin. At the same time, a loud shock noise was emitted. When the friction plate is observed after the measurement, permanent deformation is observed near the end on the sheared side, and this permanent deformed portion is presumed to be the cause of the negative gradient and impact noise.

[0014]

As is apparent from the above description, a plurality of hard plates having rigidity and a plurality of soft plates having viscoelastic properties are alternately laminated between the upper and lower face plates of the seismic isolation structure. In the inside of the composite laminated body, a hole penetrating the composite laminated body is provided, and the elastic modulus of a plurality of sheets is 1.5 × 10 ⁵ K in the hole.
By laminating a friction plate made of a polymer material having a gf / cm ² or less, a seismic isolation structure that is effective not only during an earthquake but also in wind sway can be obtained.

[0015]

[Brief description of drawings]

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

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

FIG. 3 is a sectional view of a seismic isolation structure according to a third embodiment of the present invention.

FIG. 4 is a cross-sectional view of a seismic isolation structure according to Comparative Example 1 of the present invention.

FIG. 5 is a hysteresis loop of the seismic isolation structure according to the first embodiment of the present invention.

FIG. 6 is a hysteresis loop of the seismic isolation structure according to the second embodiment of the present invention.

FIG. 7 is a hysteresis loop of a base isolation structure according to a third embodiment of the present invention.

FIG. 8 is a hysteresis loop of the seismic isolation structure according to Comparative Example 1 of the present invention.

[Explanation of symbols]

 1: Hard plate 2: Soft plate 3: Top plate 4: Bottom plate 5: Outer rubber 6: Friction plate 7: Female screw 8: Male screw 9: Disc spring 10: Rubber plate

Claims (4)

[Claims] 1. A composite laminate, in which a plurality of rigid hard plates and a plurality of soft plates having viscoelastic properties are alternately laminated between upper and lower face plates, and the inside of the composite laminate is further provided. In the seismic isolation structure in which a plurality of friction plates are laminated in the hole, the friction plate has an elastic modulus of 1.5 ×
A seismic isolation structure characterized by being a polymer material of 10 ⁵ Kgf / cm ² or less. 2. The friction plate has a pushing force of 5 Kgf / cm ² to 150 in a hole penetrating inside the composite laminate.
The seismic isolation structure according to claim 1, wherein the seismic isolation structure is filled with Kgf / cm ² . The thickness t _Friction according to claim 3, wherein the friction plate, the thickness of one said flexible plate is taken as t _R, is t _Friction ≦ t _R, and the diameter d of the friction plate, said composite When the height of the laminated body is H, the total thickness of the soft plate is h, and the diameter of the hard plate is D, d ≧ 10 (h / (H-t _Masato )) t _Masato 0.1 ≦ ( The seismic isolation structure according to claim 1 or 2, wherein d / D) ≦ 0.8. 4. The friction plate is nylon, polyethylene, polyester, polypropylene, polyvinyl chloride,
Alternatively, the seismic isolation structure according to any one of claims 1 to 3, wherein the seismic isolation structure is made of a material in which one or more unsaturated polyester resins are combined.