JPH11350783A - Vibration-isolating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration-isolating system for lightweight load having an excellent vibration-isolating effect to an earthquake regardless of the conditions of vibrations even to the load of a lightweight article and having even the superior returnability after deformation and capable of being applied even to a detached house, lightweight facilities and device, etc. SOLUTION: The vibration-isolating system 10 is installed between a ground 12 and a structure or a supporting substrate 14 for the structure. The vibration- isolating system 10 has a slider 20 having a function, in which a first supporter 16 and a second supporter 18 are slid mutually and vibrations are damped, and a rubber composite body 22 at that time. The coefficient of dynamic friction on the contact surfaces of the mutually slid first supporter and second supporter in the slider 20 extends from 0.02 to 0.10 under the conditions of measurement at a temperature of 25 deg.C, face pressure of 100 kg/cm<2> and sliding velocity of 30 cm/sec, and the load burden rate of the slider to the total supporting load of the vibration-isolating system is 50% or more.

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 lightly-loaded seismic isolation system which can be suitably applied to a light-duty detached house, equipment and devices.

[0002]

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

However, in order to make a detached house, which is extremely lightweight compared to a concrete building, a seismic isolation structure,
In particular, to obtain the same level of performance (same cycle) as a seismic isolation building, it is necessary to lower the shear rigidity of the seismic isolation rubber in proportion to the load per seismic isolation rubber.

In order to lower the shear stiffness of the base-isolated rubber, a rubber material having an extremely low elastic modulus is used, or the shape of the base-isolated rubber is made vertically long (having a height higher than the diameter of the base-isolated rubber). However, when the elastic modulus of the rubber material is extremely reduced, disadvantages such as an increase in creep become significant. On the other hand, if the laminated rubber has a vertically long structure in order to reduce the shear rigidity of the seismic isolation rubber, the laminated rubber will easily buckle during horizontal shear deformation, especially when the load increases from the vertical direction supported by the laminated rubber. In addition, the buckling limit (horizontal displacement until buckling) of the laminated rubber is greatly reduced. That is, the more the vertical load is applied to the laminated rubber, the more easily the laminated rubber buckles.

On the other hand, another structure used for vibration damping in the seismic isolation system is a damper. The role of the damper is to realize an energy damping function for making the sway of the frame as fast as possible and for reducing the sway itself. . An example of such a damper is a slider that utilizes a frictional force generated between two friction plates. The slider has an excellent damping function and can be effective against light loads. However, if a phenomenon (negative pressure) occurs in which a part of the frame rises due to rocking during an earthquake, two friction plates will be used. There is a problem that it is separated vertically and the frictional force becomes zero.

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

In this case, it has been found that if the coefficient of friction of the slider used in combination with the laminated rubber is large, there is a merit of increasing the damping effect and a disadvantage of greatly increasing the horizontal shear rigidity of the entire system.
There was a problem that desired seismic isolation performance could not be obtained simply by using the laminated rubber and the slider together.

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a detached house having an excellent seismic isolation effect against an earthquake and good returnability after deformation irrespective of vibration conditions even under the load of a lightweight object. It is an object of the present invention to provide a light-load seismic isolation system that can be applied to light-weight equipment and devices.

[0009]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that in a seismic isolation system for a detached house having a slider and a rubber composite such as laminated rubber, each of the slider and the rubber composite is suitable. By setting an appropriate load rate, a light-load seismic isolation system that exhibits excellent seismic isolation performance can be provided.In addition, an appropriate spring constant is set for the rubber composite, and an appropriate coefficient of friction is set for the slider. It has been found that the effect is further improved by setting, and the present invention has been completed.

That is, the seismic isolation system of the present invention is a seismic isolation system provided between the ground and a structure or a support substrate thereof, wherein the first support and the structure attached to the ground or the support substrate thereof are provided. A slider having a function of damping vibration by sliding with each other, and a rubber composite having a spring function, wherein the slider slides with each other to dampen vibration. The coefficient of kinetic friction at the contact surface between the first support and the second support having a function of performing is as follows: a temperature of 25 ° C., a surface pressure of 100 kg / cm ² ,
It is 0.02 or more and 0.10 or less under the measurement condition of the sliding speed of 30 cm / sec, and the load share ratio of the slider to the total support load of the seismic isolation system is 50% or more.

[0011] Here, the spring constant K of the rubber composite is 2
Under the measurement conditions of 5 ° C. and 0.5 Hz, 2 ≦ K ≦ 200 kg /
cm is a preferred embodiment. Further, from the viewpoint of the effect, it is preferable to use a laminated rubber obtained by alternately laminating a hard plate and a rubber plate as the rubber composite.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The seismic isolation system of the present invention is described below.
This will be described in more detail below.

FIG. 1 is a conceptual diagram showing one embodiment of the seismic isolation system 10 of the present invention, which is a structure in which a structure such as a building 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 attached to the ground 12 by a first support 1.
6 and a second support 18 attached to the support substrate 14 of the building, and a slider 20 having a function of attenuating vibration by sliding together with each other and a rubber composite material having a spring function, in this example, a laminated rubber. 22.

First, in the seismic isolation system for supporting a lightweight structure, a description will be given of the load share of the slider when the rubber composite such as laminated rubber and the slider are installed in parallel.

In the conventional seismic isolation system for concrete buildings, a part of the seismic isolation rubber is used to provide a damping effect.
In some cases, a slider is installed along with the slider.
%, And stayed in a very small range. However, in the case of an ultra-light seismic isolation system, as described above, the slider supported as much load as possible and the rubber bearing with less load support It is preferable in terms of buckling of the seismic rubber.

Therefore, specifically, the load share ratio of the slider (weight supported by the slider / total weight of the building)
Is preferably 50% or more, more preferably 70% or more,
It is more preferably at least 80%. Of course, the slider may support a 100% load. When the slider supports a 100% load, the rubber composite used in combination is, for example, in a structure or its supporting substrate, a place where a load is not applied is selected and arranged, or the height of the rubber composite is It is arranged so as not to receive a load unless a shear force is applied, such as being arranged so that the height of the seismic isolation system in which it is arranged is the same.

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 undesirably reduced.

Further, it is preferable from the viewpoint of the effect that the slider used in the seismic isolation system of the present invention should appropriately select the dynamic friction coefficient. FIG. 2 is a schematic cross-sectional view showing an embodiment of the slider 21 that can be suitably used in the seismic isolation system of the present invention. Friction plates 28 and 30 are arranged on contact surfaces between 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 made of a material having a suitable coefficient of friction such as metal, and the support and the friction plate 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 not only the cycle is shortened, the seismic isolation effect is greatly reduced, but also the heat generated during friction is reduced. It becomes larger and promotes fatigue of the friction plate. On the other hand, if the coefficient of friction is too small, the damping effect will be insufficient and the displacement of the building during an earthquake will increase significantly.

Therefore, a slider used in an ultra-light seismic isolation system for a detached house needs to 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 conditions of sec is 0.02
≦ μ ≦ 0.10, more preferably 0.03 ≦ μ ≦ 0.08, and most preferably 0.035 ≦ μ ≦ 0.07.

When the dynamic friction coefficient μ exceeds 0.1, the horizontal rigidity of the seismic isolation system is extremely increased, 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 building is liable to be shaken by the wind. These dynamic friction coefficients can be adjusted by selecting the material of the friction plate constituting the slider. From the viewpoint of achieving a balance between the dynamic friction coefficient and the strength of the support, a structure having a friction plate is preferable.

Here, as a material that can be used for the friction plate disposed on the surface where both supports come into contact, 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 its surface subjected to processing such as metal plating, ceramic spraying and Teflon coating, a glass fiber, a Teflon plate reinforced with carbon fiber, etc., nylon, polyethylene, polypropylene, poly Polymer materials such as acrylates and those materials have a weight average molecular weight of 10
A polymer material or the like having a low friction coefficient obtained by mixing 100 to 5 million silicone oil or silicone resin is preferably used.

The two friction plates that fold with each other may be formed of the same material or different materials. However, from the viewpoint of achieving the preferable coefficient of dynamic friction, at least one of the two friction plates is formed. 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 preferable to be coated with a resin blend, or (4) to have micropores and to contain oil such as silicone oil therein.

The structure may be such that a friction plate made of one or several kinds of the above-mentioned materials comes into contact with a friction surface, and a slider generally has a smaller one of the two contacting surfaces. For example, one support may have a columnar shape, the other support may have a flat plate shape, and both supports may have a columnar shape.

Further, if dust or dirt adheres to the surface of the slider friction plate, the friction coefficient may change over time. Therefore, as shown in a schematic sectional view in FIG. It is also a preferable embodiment to fix a skirt made of rubber or cloth so that dirt, dust and the like do not enter in between, and protect the friction surface. FIG. 3 shows a thin sheet 32 made of rubber.
FIG. 7 is a schematic cross-sectional view showing a slider 34 in a state in which is fixed between a first support 24 and a 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 ultra-light detached house is that the rubber composite such as seismic isolation rubber must have very low horizontal shear rigidity.
However, if it is too low, there will be no pullback force to restore the entire seismic isolation structure after deformation. Therefore, in a rubber complex for a seismic isolation system of a detached house having a total weight of about two digits smaller than that of a concrete building, for example, the spring constant K of one laminated rubber during shear deformation is 2 ≦ K ≦ 200 kg. / Cm or so.

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

By the way, 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 a part of the total weight of the frame is borne by the seismic isolation rubber. Of course, in other cases where a pull-out force (negative pressure) is generated in the building, the seismic isolation rubber is also effective in the sense that it exhibits resistance to pull-out. Therefore, if the seismic isolation rubber does not bear the load, that is, if the load load ratio of the slider is 100%, as the rubber composite used together, the laminated rubber generally used for the seismic isolation structure is the best.

FIG. 4 is a schematic sectional view showing an example of a laminated rubber 22 which 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. Is covered with a skin rubber 40 as a protective material. At the upper end and the lower end of the laminated rubber 22, flanges 42 and 44 for fixing the laminated rubber 22 to the ground 12, the structure or its supporting substrate 14, respectively are provided.

As a rubber composite, besides this laminated rubber,
For example, a composite in which fine rubber such as rubber string is bundled, a rod-shaped rubber, or a rubber composite in which a key-like portion for fixing and an opening are provided at both ends of the rod-shaped rubber are also effective. What is necessary is just to connect between a ground and a structure or its support substrate by such a rubber composite. FIGS. 5A and 5B are perspective views showing aspects of a rubber composite used in place of the laminated rubber. FIG.
FIG. 3 is a conceptual diagram showing a seismic isolation system 48 including the slider 20 and the bar-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 share of the slider is 100%, the rubber composite as the spring function body is excellent in the laminated rubber for seismic isolation. This is primarily due to the fact that the horizontal shear deformation shows a smooth linear stress-strain curve.
In addition, if the building rises during an earthquake and pull-out force (negative pressure) is generated in the seismic isolation device, the rubber string or rubber rod hardly exhibits resistance, but the laminated rubber has strong resistance (high vertical rigidity). This is because In this sense, the laminated rubber plays the role of an anchor bolt in the slider-centered light-load seismic isolation system. In this case, the desirable shape of the laminated rubber is such that the thickness of the rubber plate forming the laminated rubber is 1 and the diameter of the laminated rubber is 1 Is defined as t, the shape ratio S [shape ratio S (= 1 / 4t)] is desirably S ≧ 25,
More preferably S ≧ 5, even more preferably S ≧ 10,
Most preferably, S ≧ 20 (see FIG. 4).

It is desirable that the setting position of the laminated rubber with respect to the slider is located at the outer peripheral portion of the structure where the pulling force is generated most. For example, when an outer peripheral portion of a building having a site area as shown in FIG. 7 is a portion having a width of 1 m with oblique lines, at least two or more laminated rubbers are desirably installed on the outer peripheral portion, and more preferably 3 More preferably, four or more laminated rubbers are arranged on the outer periphery.

[0034]

EXAMPLES Hereinafter, the present invention will be described specifically 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 configuration 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.
This is the same as that shown in the schematic sectional view of FIG. That is, the laminated rubber 22 was obtained by alternately laminating a rubber plate and an iron plate, and the spring constant at the time of 100% shear deformation was 20 kg / cm.

FIG. 2 is a schematic view of the slider 20 used in the present embodiment. A fluororesin is provided at the lower end of a stainless steel plate 24 (# 400 abrasive, 600 mmφ, also serving as a friction plate) as a first support. Using a Teflon plate 28 coated with a mixture of and a polyamide-imide resin to a thickness of 20 μm, using an iron plate as the second support 26, and further adding a mixture of a fluororesin and a polyamide-imide resin on the upper end. Teflon plate 3 coated to 20 μm
0 (100 mmφ) was used as a friction plate. The friction coefficient generated on the friction surface is 30 cm / sec, and μ = 0. 05.

In this embodiment, the body weight is 50 ton.
(A detached house) is supported by four laminated rubbers 22 and five sliders 20. Slider 20 at this time
Was 50%.

The equivalent rigidity G of the obtained seismic isolation system is very soft, and the period T, T (= 2π√M / G, where M is the total weight of 50 tons) of the resulting system is 3 It was found that it exhibited an excellent seismic isolation effect of 0.75 seconds.

(Embodiment 2) The supporting position (arrangement position) of the laminated rubber 22 is adjusted to reduce the load burden ratio of the slider 20 to 75.
The seismic isolation system was configured in the same manner as in Example 1, except for the percentage. When evaluated in the same manner as in Example 1, it was found that the cycle T of the system was 3.40 seconds, indicating 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.
The seismic isolation system was configured in the same manner as in Example 1, except for the percentage. When evaluated in the same manner as in Example 1, it was found that the period T of the system was 3.15 seconds, indicating an excellent seismic isolation effect.

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

Comparative Example 1 As a rubber plate used for the laminated rubber 22, 1 was obtained by alternately laminating a rubber plate and an iron plate.
Using a slider having a spring constant at the time of 00% shear deformation of 300 kg / cm and a slider made of a combination of a fiber reinforced nylon plate and a stainless steel plate, the friction coefficient generated on the friction surface is 30 cm / sec, μ = 0. A seismic isolation system was configured in the same manner as in Example 1 except that the number was 2. 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 extremely small.

[0044]

[Table 1] As is clear from Table 1, the seismic isolation systems of Examples 1 to 3 of the present invention satisfy the required items of the present invention, both in the slider load sharing ratio and the spring constant μ per laminated rubber. It was found that the equivalent rigidity G of the whole system of the system thus obtained was very soft and exhibited an excellent seismic isolation effect in which 3 seconds occurred.

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

[0046]

According to the seismic isolation system of the present invention, the seismic isolation effect against an earthquake can be obtained even with a light load.
Excellent in both anti-vibration effects against wind turbulence, even if the conditions of vibration are negative pressure, the effect is not impaired, good returnability after deformation, even for light loads such as detached houses, lightweight equipment, equipment, etc. This has the effect of being suitable.

[Brief description of the drawings]

FIG. 1 is a schematic view showing one embodiment of the seismic isolation system of the present invention.

FIG. 2 is a schematic cross-sectional view illustrating one embodiment of a slider.

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

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

5A and 5B 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 illustrating one embodiment of a seismic isolation system including a slider and a bar-shaped rubber composite.

FIG. 7 is a plan view showing an outer peripheral portion of a building where a laminated rubber is desirably installed by hatching.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Seismic isolation system 20 Slider 21 Slider 24 Slider friction plate (upper end) 26 Slider friction plate (lower end) 34 Slider 22 Composite laminate 36 Hard plate 38 Soft plate 46 Rod-shaped rubber composite

Claims (3)

[Claims] 1. A seismic isolation system provided between a ground and a structure or a support substrate thereof, wherein the first support is attached to the ground and a second support is mounted to the structure or the support substrate. A first support having a slider having a function of attenuating vibration by sliding with each other and a rubber composite having a spring function, wherein the first support of the slider having a function of sliding by each other to attenuate vibration And the dynamic friction coefficient at the contact surface of the second support is a temperature of 25 ° C., a surface pressure of 100 kg / c.
m ² , at a sliding speed of 30 cm / sec.
A seismic isolation system characterized by being not less than 02 and not more than 0.10, and having a slider load bearing ratio of 50% or more with respect to the total supporting load of the seismic isolation system. 2. The rubber composite has a spring constant K of 25 ° C.
2 ≦ K ≦ 2 under the measurement conditions of 0.5 Hz and 100% deformation
The seismic isolation system according to claim 1, wherein the weight is 00 kg / cm. 3. The seismic isolation system according to claim 1, wherein a laminated rubber obtained by alternately laminating hard plates and rubber plates is used as the rubber composite.