JP4565295B2 - Seismic isolation device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a seismic isolation structure, and more particularly to a seismic isolation device that is optimally applied to a relatively small building such as a wooden house.
[0002]
[Prior art]
As is well known, the seismic isolation structure supports the entire building with seismic isolation devices such as laminated rubber, which prolongs the natural period, thereby significantly reducing the seismic force transmitted to the building and causing earthquake damage. Can be mitigated and is becoming widespread in large buildings.
[0003]
[Problems to be solved by the invention]
In recent years, there has been a demand for adopting seismic isolation structure not only for large-scale buildings but also for small-scale buildings such as detached wooden houses. Since the cost is high and the horizontal displacement of the building is usually excessive, it is desired to develop an effective seismic isolation device that can be applied to small buildings such as wooden houses.
[0004]
[Means for Solving the Problems]
The invention of claim 1 is a seismic isolation device interposed between a lower structure and an upper structure of a building, and is fixed to one of the lower structure and the upper structure. A plate-like member whose surface is a support surface, fixed to one of the other, protrudes toward the plate-like member side, and its tip abuts against the support surface of the plate-like member in a horizontally displaceable state. A projecting member for supporting the upper structure; and a damping means interposed between the plate-like member and the projecting member, and a support surface of the plate-like member serving as the damping means. A protruding body is formed in a state of penetrating through the lid body, the outer circumferential portion of the lid body and the outer circumference of the plate-shaped member. It is characterized in that a viscoelastic body as another damping means is interposed between the two portions .
[0006]
According to a second aspect of the invention, in the seismic isolation device of the first aspect of the invention, the sheet-like elastic body as the damping means is made of a high damping rubber.
[0011]
A third aspect of the present invention, in the seismic isolation device of any one of the claims 1-2, characterized in that the supporting surface of the plate-like member has a concave surface.
[0012]
According to a fourth aspect of the present invention, in the seismic isolation device according to any one of the first to third aspects of the present invention, the protruding member is a caster having a rotatable ball at a tip portion thereof.
[0013]
According to a fifth aspect of the present invention, in the seismic isolation device according to any one of the first to third aspects, the tip end portion of the protruding member is formed into a smooth spherical surface.
[0014]
The invention according to claim 6 is the seismic isolation device according to any one of claims 1 to 5 , wherein the surface of the support surface is a rough surface or an adhesive surface.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
A seismic isolation device A which is an embodiment of the present invention will be described with reference to FIGS. A large number of seismic isolation devices A according to the present embodiment are installed between a foundation (cloth foundation) 1 and a base 2 for a flat wooden house as shown in FIG.
Note that a pillar 4 is joined to the base 2 by a hole-down hardware 3 to form an upper structure of the building, and the entire upper structure is a connecting member 5 that connects the seismic isolation devices A together. As a result, the seismic isolation device A supports the base isolation.
[0017]
The seismic isolation device A in the present embodiment is mainly composed of a plate-like member 11 fixed to the foundation 1 and a caster 12 (protruding member) fixed to the base 2 via a connecting member 5. Yes.
[0018]
The plate-like member 11 is obtained by laminating a sheet-like elastic body 14 on the upper surface of a circular saucer-shaped curved steel plate 13 that is curved so as to be a concave curved surface, and the upper surface of the elastic body 14 is the tip of the caster 12. The elastic body 14 absorbs the rolling energy of the casters 12 to obtain a damping effect. That is, the elastic body 14 in the seismic isolation device A functions as a damping means, and in this example, a high damping rubber having a thickness of about 5 mm is employed as the elastic body 14. Further, for example, a steel plate having a thickness of 4.5 mm is used as the curved steel plate 13, and a rising wall portion 15 is formed on the outer periphery thereof, and the inner surface side of the rising wall portion 15 is an inclined surface 16. It is said that. A reinforcing member 17 made of precast concrete is integrated on the bottom surface side of the curved steel plate 13.
[0019]
The caster 12 has a rotatable ball 18 at the tip (lower end) thereof, and the caster 12 and the entire upper structure to which the caster 12 is fixed as a result of the ball 18 rolling on the support surface 14a. The plate-like member 11 is supported in a state in which it can be displaced relative to the horizontal direction. A cover 19 that covers the support surface 14 a of the plate-like member 11 is attached to the caster 12, and the caster 12 protrudes downward in a state of passing through the center of the cover 19. The lid 19 is a circular flat plate made of a steel plate having a thickness of 4.5 mm, similar to the curved steel plate 13. The rising wall formed on the outer periphery of the lid 19 and the outer periphery of the curved steel plate 13. Between the part 15, the cyclic | annular viscoelastic body 20 is interposed in the state adhere | attached on both. The viscoelastic body 20 also functions as another damping means that is indirectly interposed between the plate-like member 11 and the caster 12 via the lid body 19 and exhibits a damping effect with respect to their relative displacement. is there. The caster 12 in the illustrated example has a single ball 18, but a caster 12 having a plurality of balls 18 can also be used. Further, when the caster 12 is displaced relative to the plate member 11 in the horizontal direction, the lid 19 tends to be slightly displaced in the vertical direction due to the deformation of the viscoelastic body 20, so that the caster 12 is moved in such a vertical direction. It is preferable that the lid body 19 be penetrated without restraining the displacement in the direction.
[0020]
In the seismic isolation device A of the present embodiment, the upper structure is supported by the plate-like member 11 fixed to the foundation 1 via the casters 12 so as to be displaceable in the horizontal direction. Can be realized. Further, the elastic body 14 and the viscoelastic body 20 are used in combination as damping means, and an excellent vibration damping effect can be obtained by the rolling energy absorption effect by the elastic body 14 and the plastic deformation energy absorption effect of the viscoelastic body 20, thereby achieving superstructure. The horizontal displacement of the object can be greatly reduced. Further, the restoring effect is naturally obtained by the support surface 14 a being a concave curved surface and the elastic restoring force of the viscoelastic body 20. According to one design example, when the natural period is set to 4 seconds, the acceleration is 120 gal and the amplitude is about 12 cm with respect to the level 2 seismic load. An effect is obtained.
[0021]
Moreover, in the seismic isolation device A of the present embodiment, there is an effect that the displacement in the vertical direction is suppressed by the sheet of the elastic body 14 made of high-damping rubber forming the support surface 14a, and in a normal time Since the ball 18 of the caster 12 bites into the elastic body 14 and the rolling of the ball 18 is restricted, the upper structure can be restrained naturally due to the wind, and the normal comfort is reduced. There is nothing.
[0022]
The seismic isolation device A according to the present embodiment uses only general-purpose materials such as a steel plate, a sheet of high damping rubber, a viscoelastic body, and a caster, and does not require any special and expensive member or material. Compared to various conventional seismic isolation devices such as the first, it can be manufactured at a much lower cost and can be sufficiently spread to wooden houses.
[0023]
Furthermore, since the seismic isolation device A of the present embodiment is provided with the rising wall portion 15 on the outer peripheral portion of the plate-like member 11, in the event of an earthquake exceeding the expected scale, it acts as a stopper to spin out the caster 12. Since it prevents it, the fail safe effect is acquired.
Moreover, since the inner surface side of the rising wall portion 15 is not the upright surface but the inclined surface 16, a buffering effect can be expected when the caster 12 collides with the inclined surface. The support surface 14 that is a concave curved surface inside the rising wall portion 15 may be a spherical surface having a constant radius of curvature as a whole. However, the curvature radius is changed in the middle of the support surface 14 at the outer peripheral portion of the plate-like member 11. It is conceivable to make the radius of curvature smaller than the radius of curvature at the central portion (that is, make the inclination with respect to the horizontal plane steeper on the outer peripheral portion side), so that the vibration suppressing effect and restoring force can be further enhanced. .
[0024]
Furthermore, since the seismic isolation apparatus A of this embodiment provided the reinforcement member 17 in the bottom face of the plate-shaped member 11, the intensity | strength and rigidity of this seismic isolation apparatus A itself can fully be ensured.
However, such a reinforcing member 17 may be omitted if unnecessary, or may be reinforced by providing a reinforcing rib on the bottom surface of the curved steel plate 13 instead of or in addition thereto.
[0025]
Next, an example of a construction method for installing the seismic isolation device A of this embodiment will be described. First, when the foundation 1 is constructed, the seismic isolation device A is positioned and temporarily supported by the support hardware 21. As the support hardware 21, one that can be expanded and contracted by screwing the nut member 23 into the bolt member 22 is used, and the upper ends of 3 to 4 support hardware 21 are set to an appropriate level, and the seismic isolation device is placed on the support hardware 21. Place A horizontally. At this time, the seismic isolation device A may be appropriately fixed to the support hardware 21, but the apparent specific gravity of the seismic isolation device A is larger than the specific gravity of the ready-mixed concrete (usually about ρ = 2.3). In this case, since the seismic isolation device A does not float up when placing concrete, it is sufficient to simply place the seismic isolation device A on the support hardware 21 in that case, and it is particularly necessary to fix it. Absent.
[0026]
Then, concrete is cast to the level of the upper surface of the rising wall portion 15 of the plate-like member 11 of the seismic isolation device A to form the foundation 1. As a result, the plate-like member 11 of the seismic isolation device A is naturally firmly fixed in a state of being embedded in the upper portion of the foundation 1, and the lid 19 and the viscoelastic body 20 are in a state of floating from the upper surface of the foundation 1. The relative displacement of the caster 12 in the horizontal direction is not constrained.
[0027]
Therefore, the connecting member 5 is bolted to the upper part of the caster 12, the seismic isolation devices A are connected by the connecting member 5, and the base 2 is attached on the connecting member 5. From then on, the superstructure should be constructed in exactly the same way as for ordinary wooden houses.
[0028]
According to the construction method described above, the seismic isolation device A can be easily and reliably installed on the foundation 1 without any troublesome labor and almost no construction cost.
[0029]
Although the seismic isolation device A which is one embodiment of the present invention has been described above, other embodiments are listed below. In the following embodiments, components having the same functions are denoted by the same reference numerals, detailed description thereof is omitted, and only differences are described.
[0030]
The seismic isolation device B shown in FIG. 4 uses a protruding member 30 having a tip formed in a spherical shape, instead of the caster 12 described above. In this seismic isolation device B, since the spherical surface at the tip of the projecting member 30 slides directly on the support surface 14a, the sliding resistance is much larger than that of the caster 12, which is necessary. If so, it is conceivable to reduce the sliding resistance by putting oil 31 on the support surface 14a as shown in the figure or by applying grease. In addition, the connection member 5 which connected the seismic isolation apparatus A in the previous embodiment is abbreviate | omitted in this example, and the base 2 shall serve as it.
[0034]
The seismic isolation device E shown in FIG. 5 adopts a flat steel plate 45 instead of the curved steel plate 13 in each of the above embodiments, and provides the elastic member 14 on the upper surface thereof, thereby making the plate member 11 flat. The support surface 14a is a flat surface without a concave curved surface. Also with this seismic isolation device E, the damping effect is obtained by the elastic body 14 forming the support surface 14 a and the viscoelastic body 20 provided on the outer peripheral portion, and the restoring effect is obtained by the elasticity of the viscoelastic body 20.
[0035]
The seismic isolation device F shown in FIG. 6 controls the damping performance by adjusting the rolling resistance of the casters 12 with the support surface 14a on the surface of the elastic body 14 in the seismic isolation device E as a rough surface. is there. The rough surface of the elastic body 14 can be easily formed by forming a rough mesh pattern or the like. Alternatively, an adhesive surface may be used instead of the rough surface. Further, a concave portion 14b is provided in the central portion of the support surface 14a, and the concave portion 14b regulates the position of the ball 18 of the caster 12 at a normal time, and the caster 12 automatically restores to the position after the earthquake. ing.
[0037]
The seismic isolation device H shown in FIGS . 7 and 8 is based on the seismic isolation device F shown in FIG. 6 , and a plurality of (four in the illustrated example) viscoelastic bodies between the plate-like member 11 and the lid 19. 20 is distributed and provided with a cover 39 covering the support surface 14a. The cover 39 functions in the same manner as the seismic isolation device of each of the above embodiments, and the same effect is obtained.
[0038]
Although the embodiment of the present invention has been described above, the seismic isolation device of the present invention is not limited to each of the above embodiments. For example , the top and bottom of the seismic isolation device of each of the above embodiments (each implementation) The plate-like member 11 in the configuration is fixed downward on the lower surface of the upper structure such as the base 2 and the casters 12 and the protruding members 30 are fixed upward on the upper structure of the lower structure such as the foundation 1). This is not possible, and there is an advantage that foreign substances can naturally be prevented by doing so. In addition, the seismic isolation device of the present invention is optimally applied to relatively small buildings such as wooden houses, but it is not limited to this and can be widely applied to buildings of any structure, scale, and usage, Of course, it can be applied not only to the basic seismic isolation structure but also to the intermediate floor seismic isolation structure.
[0039]
【The invention's effect】
The seismic isolation device of the invention of claim 1 supports the upper structure by bringing the tip of the protruding member into contact with the support surface of the plate-like member in a horizontally displaceable state, and supporting the upper member. Since it is the structure which interposed the attenuation | damping means between the protruding members, the long-perioding function and the attenuation function for the building can be obtained, and excellent seismic isolation performance can be obtained.
[0040]
In particular, in the seismic isolation device of the first aspect of the invention, since the support surface of the plate-like member is formed by a sheet-like elastic body as a damping means, a damping effect by the elastic body can be obtained, and the elastic body creeps normally. It is possible to effectively prevent shaking due to the wind of time.
In addition, the seismic isolation device according to the first aspect of the present invention allows the projecting member to pass through the lid that covers the support surface of the plate-like member, and another damping is provided between the outer periphery of the lid and the outer periphery of the plate-like member. Since the viscoelastic body as a means is interposed, it is possible to obtain an excellent attenuation effect and restoration effect by the viscoelastic body, and to prevent foreign matter from entering the inside by the lid body.
[0041]
In the seismic isolation device according to the second aspect of the present invention, the high damping rubber is used as the elastic body, so that the damping effect can be sufficiently enhanced and the vibration in the vertical direction can be effectively suppressed.
[0046]
In the seismic isolation device according to the third aspect of the invention, since the support surface of the plate-like member is a concave curved surface, the vibration suppressing effect is enhanced and the restoring force is naturally obtained.
[0047]
In the seismic isolation device according to the fourth aspect of the invention, since the caster is employed as the projecting member, the upper structure can be horizontally displaced reliably and smoothly by rolling the ball of the caster.
[0048]
In the seismic isolation device according to the fifth aspect of the present invention, since the tip end portion of the projecting member is formed into a smooth spherical surface, the sliding resistance of the projecting member with respect to the support surface is reduced, and the upper structure is displaced horizontally and reliably. Can be made.
[0049]
In the seismic isolation device according to the sixth aspect of the invention, since the surface of the support surface is a rough surface or an adhesive surface, it is possible to control the seismic isolation effect by suppressing the horizontal displacement of the protruding member.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing an embodiment of a seismic isolation device of the present invention.
FIG. 2 is a plan sectional view of the same.
FIG. 3 is a plan view showing an arrangement example of the seismic isolation device for the wooden house.
FIG. 4 is a side sectional view showing another embodiment of the seismic isolation device of the present invention.
FIG. 5 is a side sectional view showing still another embodiment of the seismic isolation device of the present invention.
FIG. 6 is a side sectional view showing still another embodiment of the seismic isolation device of the present invention.
FIG. 7 is a side sectional view showing still another embodiment of the seismic isolation device of the present invention.
FIG. 8 is a plan sectional view of the same.
[Explanation of symbols]
A, B, E, F, H Seismic isolation device 1 Foundation (substructure)
2 foundation (superstructure)
5 connecting material 11 plate-like member 12 caster (protruding member)
13 Curved steel plate 14 Elastic body (damping means)
14a Support surface 14b Recess 15 Rising wall 16 Inclined surface 17 Reinforcing member 18 Ball 19 Lid 20 Viscoelastic body ( other damping means )
30 Protruding member
39 Cover (cover)

Claims (6)

A seismic isolation device interposed between a lower structure and an upper structure of a building, which is fixed to one of the lower structure and the upper structure and has a surface as a support surface A protrusion that is fixed to one of the plate members and protrudes toward the plate member, and that supports the upper structure by abutting the tip of the plate member in a horizontal direction relative to the support surface of the plate member. And a damping means interposed between the plate-like member and the protruding member ,
The support surface of the plate-like member is formed by a sheet-like elastic body as the damping means ,
Provide a lid that covers the support surface of the plate-like member, and provide the protruding member in a state of passing through the lid, and another attenuation between the outer periphery of the lid and the outer periphery of the plate-like member A seismic isolation device comprising a viscoelastic body as a means. The seismic isolation device according to claim 1 , wherein the sheet-like elastic body as the damping means is made of high damping rubber. 3. The seismic isolation device according to claim 1 , wherein the support surface of the plate-shaped member is a concave curved surface. The seismic isolation device according to any one of claims 1 to 3 , wherein the protruding member is a caster having a rotatable ball at a tip portion thereof. The seismic isolation device according to any one of claims 1 to 3 , wherein a tip of the protruding member is formed into a smooth spherical surface. 6. The seismic isolation device according to claim 1 , wherein the surface of the support surface is a rough surface or an adhesive surface.

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