JP2003213961A - Base-isolating system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a base-isolating system for light load applied to a detached house, a lightweight facility, equipment or the like superior in base isolation effect to an earthquake regardless of vibration conditions for load of a lightweight matter, and superior in return after deformation. <P>SOLUTION: The base-isolated system provided between ground 12 and a structure or its support board 14 is provided with a slider 20 and a rubber complex 22 having a function attenuating vibration by mutually allowing a first supporter 16 and a second supporter 18 to slide against each other. A dynamic friction coefficient F on a contact face between the first and second mutually sliding supporters in the slider 20 is 0.02≤Fe≤0.10 under measured conditions of a temperature of 25°C, 100 kg/cm<SP>2</SP>of face pressure and 30 cm/sec of slide speed. A load burden ratio of the slider to the whole support load of the base isolating system is ≥50%. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation system, and more particularly to a seismic isolation system for light loads, which can be suitably applied to detached houses and facilities and devices.

[0002]

2. Description of the Related Art Conventionally, as a seismic isolation device for a seismic isolation structure for protecting a structure from an earthquake, in addition to seismic isolation rubber which is a laminated body of rubber and an iron plate, two friction plates are combined. Methods using sliders and bearings have been studied. At present, seismic isolation rubber is generally used as a seismic isolation device for heavy structures such as concrete buildings.

However, in order to provide a base-isolated structure for a detached house, which is extremely lighter than a concrete building,
In particular, in order to obtain the same level of performance (same cycle) as that of a seismic isolated building, it is necessary to lower the shear rigidity of the seismic isolated rubber in proportion to the load per seismic isolated rubber.

To reduce the shear rigidity of seismic isolation rubber, use a rubber material with an extremely low elastic modulus, or make the shape of the seismic isolation rubber vertically long (higher than the diameter of the seismic isolation rubber). However, if the elastic modulus of the rubber material is extremely lowered, the drawbacks such as increase in creep become remarkable. On the other hand, if the laminated rubber has a vertically long structure in order to reduce the shear rigidity of the base-isolated rubber, the laminated rubber tends to buckle during horizontal shear deformation, especially when the load increases from the vertical direction supported by the laminated rubber. The buckling limit (horizontal displacement until buckling) of the laminated rubber is significantly reduced. That is, the more vertical load is applied to the laminated rubber, the more likely the laminated rubber will buckle.

On the other hand, a damper is mentioned as another structure used for vibration damping in the seismic isolation system, and the role of the damper is to express an energy damping function for making the body sway as fast as possible and reducing the sway itself. . An example of such a damper is a slider that utilizes the frictional force generated between two friction plates. The slider has an excellent damping function and can exert an effect even for a light load, but if a phenomenon (negative pressure) occurs such that part of the body is lifted due to locking during an earthquake, the two friction plates There is a problem that it is separated into upper and lower parts and the frictional force becomes zero.

Therefore, as a solution, a system in which a certain weight portion of the total weight of a building structure is supported by a laminated rubber and the remaining weight portion is supported by a slider can be considered. In other words, it is a seismic isolation system that supports a building with laminated rubber and sliders.

In this case, it has been found that a large friction coefficient of the slider used in combination with the laminated rubber brings about a merit of enhancing the damping effect and a demerit of greatly increasing the shear rigidity in the horizontal direction of the entire system.
There is a problem that the desired seismic isolation performance cannot be obtained by simply using the laminated rubber and the slider together.

[0008]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a detached house which has an excellent seismic isolation effect against an earthquake regardless of the load condition of a lightweight object and has a good return property after deformation. It is to provide a seismic isolation system for light loads that can be applied to lightweight equipment and devices.

[0009]

As a result of intensive studies, the present inventors have found that in a seismic isolation system in which a slider and a rubber composite such as a laminated rubber are provided together, an appropriate load load is applied to each of the slider and the rubber composite. By setting the rate, it is possible to provide a seismic isolation system for light loads that exhibits excellent seismic isolation performance. Furthermore, set an appropriate spring constant for the rubber composite and an appropriate friction coefficient for the slider. As a result, they found that the effect was further improved, and completed the present invention.

That is, the seismic isolation system of the present invention is a seismic isolation system provided between the ground and a structure or a supporting substrate thereof, wherein the first support and the structure mounted on the ground or a supporting substrate thereof. And a rubber composite having a spring function, and a slider having a function of sliding on each other to damp the vibration, and a rubber composite having a spring function. The dynamic friction coefficient at the contact surface of the first support and the second support having the function of controlling the temperature is 25 ° C., the surface pressure is 100 kg / cm ² ,
It is characterized in that it is 0.02 or more and 0.10 or less under the measurement condition of the sliding velocity of 30 cm / sec, and the load bearing ratio of the slider with respect to the total supporting load of the seismic isolation system is 50% or more.

Here, the spring constant K of the rubber composite is 2
2 ≦ K ≦ 200 kg / under measurement conditions of 5 ° C. and 0.5 Hz
The preferred embodiment is cm. Further, it is preferable from the viewpoint of effect that a laminated rubber obtained by alternately laminating hard plates and rubber plates is used as the rubber composite.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Regarding the seismic isolation system of the present invention,
The details will be described below.

FIG. 1 is a conceptual diagram showing one embodiment of a seismic isolation system 10 of the present invention, which has a structure in which a structure such as a structure is supported in parallel by a composite laminate and a slider. This seismic isolation system 10 is provided between a ground 12 and a support substrate 14 of a structure, and is a first support 1 attached to the ground 12.
6 and a second support 18 attached to the support substrate 14 of the structure, and a slider 20 having a function of damping each other by vibrating each other, and a rubber composite material having a spring function, a laminated rubber in this example. 22 and 22.

First, in a seismic isolation system for supporting a lightweight structure, a load bearing ratio of a slider when a rubber composite such as laminated rubber and a slider are installed in parallel will be described.

In a conventional seismic isolation system for a concrete building, a part of the seismic isolation rubber is used to provide a damping effect.
A slider is also installed side by side, but in that case, the load bearing ratio of the slirder is almost 10 at maximum.
However, in the case of the ultra-lightweight seismic isolation system, the slider supports as much load as possible and the seismic isolation rubber load support is less as mentioned above. It is preferable in terms of buckling of the seismic rubber.

Therefore, specifically, the load bearing ratio of the slider (weight supported by the slider / total weight of the building)
Is preferably 50% or more, more preferably 70% or more,
More preferably, it is 80% or more. Of course, the slider may support 100% load. When the slider supports a 100% load, the rubber composite used in combination may be arranged, for example, in a structure or its supporting substrate by selecting a location where a load is not applied, or by arranging the height of the rubber composite. It is placed so that it is not loaded unless shear forces are applied, such as it is placed at the same height as the seismic isolation system in which it is placed.

If the load bearing ratio of the slider is less than 50%, the load bearing of the seismic isolation rubber becomes too large and the buckling limit is significantly reduced, which is not preferable.

Further, it is preferable from the viewpoint of effect that the dynamic friction coefficient of the slider used in the seismic isolation system of the present invention is appropriately selected. FIG. 2 is a schematic cross-sectional view showing an aspect of the slider 21 that can be preferably used in the seismic isolation system of the present invention. Friction plates 28 and 30 are arranged on the contact surfaces of the lower end of the first support 24 and the upper end of the second support 26, respectively. Further, the supports 24 and 26 may be formed of a material having a suitable friction coefficient such as metal, and the supports and the friction plates may be integrated.

As described above, if the friction coefficient of the slider is large, the rigidity of the seismic isolation system in the horizontal direction is increased, so that the period is shortened and the seismic isolation effect is significantly reduced. It becomes larger and promotes fatigue of the friction plate. On the other hand, if the coefficient of friction becomes too small, the damping effect will be insufficient and the displacement of the building during an earthquake will increase significantly.

Therefore, the slider used for the ultra-lightweight seismic isolation system for detached houses must have an appropriate coefficient of friction.
5 ° C, surface pressure 100 kg / cm ² , sliding speed 30 cm /
The dynamic friction coefficient μ obtained under the measurement condition of sec is 0.02.
It is preferable that ≦ μ ≦ 0.10, more preferably 0.03 ≦ μ ≦ 0.08, and most preferably 0.035 ≦ μ ≦ 0.07.

When the coefficient of dynamic friction μ exceeds 0.1, the horizontal rigidity of the seismic isolation system becomes extremely high, which is not preferable. On the other hand, when μ is less than 0.03, the damping effect of the system is insufficient, the displacement of the building during an earthquake increases, and the wind easily shakes. These dynamic friction coefficients can be adjusted by selecting the material of the friction plate forming the slider. From the viewpoint of satisfying both the dynamic friction coefficient and the strength of the support, the structure having a friction plate is preferable.

As a material which can be used for the friction plate arranged on the surface where both supports come into contact with each other, any material having a dynamic friction coefficient μ within the range required by the present invention is effective. For example, a metal plate, a ceramic plate, a plastic plate and the surface of which is subjected to processing such as metal plating, ceramic spraying and Teflon (R) coating, Teflon (R) reinforced with glass fiber, carbon fiber, etc.
Plates, polymeric materials such as nylon, polyethylene, polypropylene, polyacrylate, etc. and polymeric materials having a low friction coefficient by mixing these materials with silicone oil or silicone resin having a weight average molecular weight of 10 to 5,000,000. It is preferably used.

The two friction plates that slide with respect to each other may be made of the same material or different materials, but from the viewpoint of achieving the preferable dynamic friction coefficient, at least one of them is used. The friction plate is (1) coated with a fluororesin or a fiber-reinforced fluororesin, (2) coated with an alloy of a fluororesin and another thermoplastic polymer, (3) a fluororesin and an epoxy. It is preferably either coated with a resin blend or (4) having fine pores containing an oil such as silicone oil.

Further, structurally, any structure may be adopted as long as the friction plates made of one or several of the above-mentioned materials come into contact with each other on the friction surface, and generally, the slider has one of the two surfaces which comes into contact with one another having a smaller size. For example, one support may have a cylindrical shape, the other support may have a flat plate shape, and both supports may have a cylindrical shape.

Further, when dust or dirt adheres to the friction plate surface of the slider, the friction coefficient may change with time. Therefore, as shown in the schematic sectional view of FIG. It is also a preferable embodiment to protect the friction surface by fixing a skirt made of rubber or cloth so as to prevent dust and dirt from getting in between. FIG. 3 shows a thin rubber sheet 32.
FIG. 6 is a schematic cross-sectional view showing a slider 34 in a mode in which is fixed between the first support 24 and the second support 26.

Next, the rubber composite used together with the slider in the seismic isolation system of the present invention will be described.

An essential condition for seismic isolation of an ultralight detached house is that the rubber composite such as seismic isolation rubber must have a very low shear rigidity in the horizontal direction.
However, if it is too low, there is no pullback force to restore the entire seismic isolation structure after deformation. Therefore, in the case of a rubber complex for seismic isolation of a house where the total weight of the skeleton is lighter by about two orders of magnitude than that of a concrete building, for example, the spring constant K during shear deformation of one laminated rubber is 2 ≦ K ≦ 200 kg. / Cm is preferable.

More preferably, 5 ≦ K ≦ 150 kg / c
m, most preferably 10 ≦ K ≦ 150 kg / cm.

The reason why the seismic isolation rubber is used as the spring mechanism together with the slider in the light load seismic isolation system of the present invention is that the seismic isolation rubber bears a portion of the total weight of the body. Of course, in addition to that, in the case where a pulling force (negative pressure) is generated in the building, the seismic isolation rubber is also effective in that it shows resistance to pulling out. Therefore, if the seismic isolation rubber does not bear the load, that is, if the load bearing ratio of the slider is 100%, the laminated rubber generally used for the seismic isolation structure is the best as the rubber composite used together.

FIG. 4 is a schematic sectional view showing an example of a laminated rubber 22 that can be suitably used in the seismic isolation system of the present invention. The laminated rubber 22 is a laminated body in which hard plates 36 and soft plates 38 are alternately laminated. It has a structure in which the periphery of is covered with an outer rubber 40 as a protective material. The upper and lower ends of the laminated rubber 22 are provided with flanges 42 and 44 for fixing the laminated rubber 22 to the ground 12, the structure or its supporting substrate 14, respectively.

As the rubber composite, other than this laminated rubber,
For example, a composite body in which thin rubbers are bundled such as a rubber string, a rod-shaped rubber, or a rubber composite body in which a locking key portion or an opening is provided at both ends of the rod-shaped rubber is also effective. Such a rubber composite may be used to connect the ground to the structure or its supporting substrate. 5A and 5B are perspective views showing a mode of a rubber composite used in place of the laminated rubber. Figure 6
FIG. 4 is a conceptual diagram showing a seismic isolation system 48 including the slider 20 and the rod-shaped rubber composite 46 as described above. As shown in FIG. 6, both ends of the rubber composite 46 may be connected to the ground 12 and the structure or its supporting substrate 14, respectively.

In the case of the light load seismic isolation system of the present invention including the case where the load bearing ratio of the slider is 100%, the seismic isolation laminated rubber is excellent as the rubber composite which is the spring function body. The first reason is that horizontal shear deformation exhibits a smooth linear stress-strain curve.
In addition, when a building floats up during an earthquake and pulls out force (negative pressure) on the seismic isolation device, rubber straps and rubber rods exert almost no resistance, but laminated rubber has strong resistance (high vertical rigidity). This is because In this sense, the laminated rubber plays a role of an anchor bolt in the light load seismic isolation system centered on the slider. At this time, the desirable shape of the laminated rubber is the thickness of the rubber plate forming the laminated rubber, and the diameter of the laminated rubber. The shape ratio S [shape ratio S (= 1 / 4t)] defined as t is preferably S ≧ 25,
More preferably S ≧ 5, even more preferably S ≧ 10,
Most preferred is S ≧ 20 (see FIG. 4).

Further, it is desirable that the set position of the laminated rubber with respect to the slider is at the outer peripheral portion of the structure where the pulling force is most generated. For example, when the outer peripheral portion of a building having a site area as shown in FIG. 7 is a 1-m wide portion of the diagonal line, it is desirable that at least two or more laminated rubbers are installed on the outer peripheral portion, and more preferably 3 Or more, and most preferably, four or more laminated rubbers are arranged on the outer peripheral portion.

[0034]

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

(Embodiment 1) A seismic isolation system 10 according to Embodiment 1 of the present invention has a structure similar to that shown in the conceptual diagram of FIG.
It is a structure to support in parallel.

The structure of the laminated rubber 22 used here is as follows.
It is similar to that shown in the schematic cross-sectional view of FIG. That is, the laminated rubber 22 was obtained by alternately laminating rubber plates and iron plates, and the spring constant at 100% shear deformation was 20 kg / cm.

A schematic view of the slider 20 used in this embodiment is as shown in FIG. 2, and a fluorine resin is attached to the lower end of the stainless plate 24 (# 400 abrasive, 600 mmφ, which also serves as a friction plate) as the first support. A Teflon (R) plate 28 coated with a mixture of a resin and a polyamide-imide resin to a thickness of 20 μm, an iron plate for the second support 26, and a mixture of a fluororesin and a polyamide-imide resin on the upper end. A Teflon (R) plate 30 (100 mmφ) coated with 20 μm in thickness was used as a friction plate. The friction coefficient generated on the friction surface is 30 cm / sec,
μ = 0. It was 05.

In this embodiment, the body weight is 50 ton.
The structure (house) is supported by four laminated rubber layers 22 and five sliders 20. Slider 20 at this time
The load bearing rate was 50%.

The equivalent rigidity G of the seismic isolation system obtained is extremely soft, and the resulting system periods T, T (= 2π√M / G, M is a total weight of 50 tons) are 3 It was found to show an excellent seismic isolation effect of 0.75 seconds.

(Embodiment 2) The load bearing ratio of the slider 20 is set to 75 by adjusting the supporting position (arrangement position) of the laminated rubber 22.
A seismic isolation system was constructed in the same manner as in Example 1 except that the percentage was changed to%. When evaluated in the same manner as in Example 1, it was found that the period T of the system was 3.40 seconds, exhibiting an excellent seismic isolation effect.

(Embodiment 3) The load bearing ratio of the slider 20 is set to 100 so that no load is applied to the laminated rubber 22.
A seismic isolation system was constructed in the same manner as in Example 1 except that the percentage was changed to%. When evaluated in the same manner as in Example 1, it was found that the period T of the system was 3.15 seconds, which was an excellent seismic isolation effect.

The structure and seismic isolation performance of these seismic isolation systems are shown in Table 1 below.

COMPARATIVE EXAMPLE 1 A rubber plate used for the laminated rubber 22 was obtained by alternately laminating a rubber plate and an iron plate.
Using a spring constant of 300 kg / cm at the time of 00% shear deformation, and using a slider formed by combining a fiber-reinforced nylon plate and a stainless plate, the friction coefficient generated on the friction surface was 30 cm / sec, and μ = 0. A seismic isolation system was constructed in the same manner as in Example 1 except that No. 2 was used. When evaluated in the same manner as in Example 1, it was found that the period T of the system was 1.18 seconds and the seismic isolation effect was very small.

[0044]

[Table 1]

As is apparent from Table 1, Example 1 of the present invention
~ The seismic isolation system of Example 3 has a slider load burden rate,
The spring constant μ per laminated rubber, both satisfy the requirements of the present invention, and the equivalent rigidity G of the entire system of the system thus obtained is extremely soft.
It has been found that it exhibits an excellent seismic isolation effect that can last 3 seconds.

On the other hand, even if the slider load bearing ratio is 50%, the seismic isolation system of Comparative Example 1 in which the dynamic friction coefficient of the slider is out of the range required by the present invention, G is larger by almost one digit than that of the embodiment, T was also a small value of 2 seconds or less, and it was found that the seismic isolation effect was very small.

[0047]

Since the seismic isolation system of the present invention has the above-mentioned structure, the seismic isolation effect against an earthquake can be achieved even for a load of a lightweight object.
It has excellent anti-vibration effect against wind sway, does not lose its effect even when the vibration condition is negative pressure, and has a good returnability after deformation.It is also suitable for light loads such as detached houses, lightweight equipment and devices. The effect that it is suitable is produced.

[Brief description of drawings]

FIG. 1 is a schematic view showing an aspect of a seismic isolation system of the present invention.

FIG. 2 is a schematic cross-sectional view showing one mode of a slider.

FIG. 3 is a schematic cross-sectional view showing a mode in which a dust adhesion preventing sheet is attached to a slider.

FIG. 4 is a schematic cross-sectional view showing one embodiment of laminated rubber that can be suitably used in the seismic isolation system of the present invention.

5 (A) and 5 (B) are schematic cross-sectional views showing one embodiment of a rod-shaped rubber composite that can be used in the seismic isolation system of the present invention.

FIG. 6 is a schematic cross-sectional view showing an aspect of a seismic isolation system including a slider and a rod-shaped rubber composite.

FIG. 7 is a plan view in which the outer peripheral portion of a building in which laminated rubber is desirably installed is shown by hatching.

[Explanation of symbols]

10 seismic isolation system 20 slider 21 Slider 24 Slider friction plate (upper end) 26 Slider friction plate (bottom end) 34 Slider 22 composite laminate 36 hard plate 38 Soft plate 46 Rod-shaped rubber composite

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F16F 15/04 F16F 15/04 PF term (reference) 3J048 AA02 AA03 AA06 AA07 AC01 AD14 BA08 BA23 BE12 BG04 DA01 EA38

Claims (4)

[Claims] 1. A seismic isolation system provided between the ground and a structure or a supporting substrate thereof, wherein a first support mounted on the ground and a second supporting body mounted on the structure or a supporting substrate thereof. And a rubber composite having a spring function, the slider having a function of dampening vibration by sliding with each other, and a first support in the slider having a function of sliding to dampen vibration And the coefficient of kinetic friction on the contact surface of the second support is a temperature of 25 ° C. and a surface pressure of 100 kg / c.
m ² and sliding speed of 30 cm / sec under the measurement conditions of 0.
A seismic isolation system, which is not less than 02 and not more than 0.10, and the load bearing ratio of the slider is 50% or more with respect to the total supporting load of the seismic isolation system. 2. The spring constant K of the rubber composite has a temperature of 25 ° C.,
2 ≦ K ≦ 2 under the measurement condition at 0.5 Hz and 100% deformation
The seismic isolation system according to claim 1, wherein the seismic isolation system is 00 kg / cm. 3. The seismic isolation system according to claim 1, wherein a laminated rubber formed by alternately laminating hard plates and rubber plates is used as the rubber composite. 4. A detached house supported by the seismic isolation system according to any one of claims 1 to 3.