JP2007247167A - Base isolation supporting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a base isolation supporting device capable of providing excellent base isolation performance by absorbing not only rolling but also deformation in the tilting direction (rotating direction). <P>SOLUTION: In this base isolation device A for supporting an article 1 to be placed on a loading base 2 for base isolation, a first base isolation support part (a) capable of absorbing the relative displacement of the article 1 to the loading base 2 in the lateral direction and a second base isolation support part (b) capable of absorbing the relative inclination of the article 1 to the loading base 2 are connected in series to each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a seismic isolation bearing device for allowing a structure, a building or the like to be seismically isolated on a mounting table such as a support pile or a concrete foundation.

  As this type of seismic isolation bearing device, as disclosed in Patent Document 1, a laminated rubber interposed between the upper end portion (pile head) of a foundation pile and a foundation of a structure (such as a footing) is used. Are known. That is, as shown in FIGS. 6 and 7, the laminated rubber B is composed of a laminated body 35 in which a plurality of elastic plates 33 and hard plates 34 are alternately laminated up and down, and a footing fixed to both upper and lower end portions thereof. It has a pair of flange plates 36 and 37 on the 32 side and foundation pile 31 side.

  Laminated rubber B is a seismic isolation device (see Fig. 6) that is suitable for absorbing lateral displacement and vibration while withstanding vertical loads, and is effective in seismic motions that sway laterally. The However, as shown in FIG. 7, when an earthquake or the like occurs, not only the roll but also the displacement in the tilt direction (twist component), that is, the rotational force in the direction of the arrow a around the rotational lateral axis acts. In some cases, the laminated rubber B may be subjected to not only lateral deformation but also rotational deformation.

That is, as shown in FIG. 7, a tilting force (bending moment) acts in a state where one side edge of the laminate 35 becomes a compression edge and the other side edge becomes a tension edge. Since the laminated rubber B is originally designed for rolling, there is a problem that proper deformation cannot be performed when the tilt force is applied simultaneously, and as a result, the predetermined seismic isolation performance cannot be exhibited.
JP 2003-138882 A

  An object of the present invention is to provide a seismic isolation bearing device that is superior in seismic isolation performance by absorbing not only the roll but also the deformation in the tilt direction (rotation direction) described above.

The invention according to claim 1 is a seismic isolation support device for causing the mounting base 2 to perform a base isolation support on the mounting table 2.
The first seismic isolation bearing part a capable of absorbing the relative lateral displacement between the mounted object 1 and the mounting table 2, and the relative inclination between the mounted object 1 and the mounting table 2. The seismic isolation bearing device A is configured by connecting an absorbable second seismic isolation bearing part b in series.

  The invention according to claim 2 is the seismic isolation bearing device according to claim 1, wherein the first seismic isolation bearing part a is a laminate 5 in which a plurality of elastic plates 3 and hard plates 4 are alternately laminated. And the flange plates 6 and 7 on the mounting object side and the mounting table side which are fixed to both ends in the stacking direction.

  The invention according to claim 3 is the seismic isolation bearing device according to claim 1 or 2, wherein the second seismic isolation support part b includes a lower support member 9 having a cylindrical cylinder part 11 opened upward; An upper support member 10 having a piston portion 12 fitted in the cylinder portion 11 in a state in which the lower support member 9 can be moved in an inclined manner, and an enclosure equipment in the cylinder portion 11 in a state of supporting the piston portion 12 It is characterized by having an elastic member 13 to be formed.

  The invention according to claim 4 is the seismic isolation bearing device according to any one of claims 1 to 3, wherein the first seismic isolation bearing part a is disposed on the second seismic isolation bearing part b. It is characterized by being.

  According to the first aspect of the present invention, since the object to be placed and the mounting base are isolated from each other by the seismic isolation device composed of the first and second seismic isolation parts, for example, from the ground Even if tilt displacement (rotation displacement) occurs in the mounting table under the influence of the input seismic force, the tilt displacement is absorbed by the second seismic isolation bearing that can absorb the relative tilt. It becomes like this. Further, even if a lateral displacement occurs in the mounting table, the lateral displacement is absorbed by the first seismic isolation bearing that can absorb the relative lateral displacement. Therefore, the first seismic isolation bearing is in a state where the original function of absorbing the displacement in the lateral direction (shear direction) can be exhibited, and the predetermined seismic isolation performance can be exhibited. As a result, it is possible to absorb not only the roll but also the deformation in the tilt direction (rotation direction), and it is possible to provide a seismic isolation bearing device with more excellent seismic isolation performance.

  According to the invention of claim 2, since the first seismic isolation bearing portion is constructed of a laminated rubber structure, while supporting a load with little displacement in the vertical direction, it can absorb even large shaking in the lateral direction. It is possible to exhibit the excellent seismic isolation bearing performance, and the effect of the invention of claim 1 can be enhanced.

  According to the invention of claim 3, since it is a means for absorbing the tilt displacement between the mounted object and the mounting table by using the thickness change (elastic deformation) of the elastic member held between the upper and lower support members, When an external force such as the above acts, the stress is released by the relative inclination (relative rotation) between the lower support member and the upper support member, and the bending moment is prevented from acting on both of them. Therefore, even when an excessive external force is applied due to an earthquake or the like, a seismic isolation bearing device is realized that exhibits excellent seismic performance and seismic isolation performance sufficient to prevent damage or breakage of the mounted object or mounting table. The

  According to invention of Claim 4, since the 1st seismic isolation support part mainly responsible for seismic isolation performance will be arrange | positioned at the to-be-mounted object side, compared with the case where this reverse arrangement structure is taken, it is mounted. The response of the figurine's roll absorption action is more agile. Therefore, it is possible to provide a preferred seismic isolation bearing device that can improve the seismic isolation performance by setting the arrangement order of the first seismic isolation bearing and the second seismic isolation bearing.

  Embodiments of the seismic isolation bearing device according to the present invention will be described below with reference to the drawings. 1 is a cross-sectional view of the seismic isolation bearing device, FIG. 2 is a schematic diagram showing a first example of use of the seismic isolation bearing device, FIG. 3 is an operation diagram showing how the seismic isolation bearing device is deformed during an earthquake, and FIG. FIG. 5 is a schematic view showing a usage example 2 of the seismic isolation bearing device.

[Example 1]
The seismic isolation bearing device A according to the first embodiment is applied to the support portion of the structure 1 shown in FIG. First, the structure support structure will be described. A concave wall 21 dug in the ground 20 is formed with a cover wall 22 composed of a retaining wall 22a and a bottom wall 22b made of concrete, and the bottom wall 22b and the ground 20 are formed. A plurality of support piles 2 having a length embedded so as to reach a hard support layer (stratum) 23 located deep in the ground through the ground. And the structure 1 is mounted in the upper end part of each support pile 2 via the seismic isolation bearing apparatus A. As shown in FIG. That is, the structure 1 is seismically isolated from the ground 20.

  As shown in FIGS. 1 and 2, the seismic isolation bearing device A has a relative lateral relationship between a structure (an example of a mounted object) 1 and a support pile (an example of a mounting table) 2 that is embedded and supported in the ground. A first seismic isolation bearing part a capable of absorbing displacement in the direction and a second seismic isolation bearing part b capable of absorbing the relative inclination of the structure 1 and the support pile 2 in a vertically connected state. It is configured by integrating.

  The first seismic isolation bearing portion a includes a laminated body 5 in which a plurality of rubber plate portions (an example of an elastic plate) 3 and circular metal plates (an example of a hard plate) 4 are alternately laminated, and upper and lower portions thereof. Each of the flange plates 6 and 7 on the structure side (an example of the mounted object side) and the support pile side (an example of the mounting table side) fixed to both ends in the direction (an example of the stacking direction). ing. The plurality of metal plates 4 are covered with the same rubber material as that of the rubber plate portion 3 so that the outer peripheral portion thereof is not exposed. As a result, each rubber plate portion 3 is connected at the outer diameter side end portion. It is of general structure.

  The upper flange plate 6 is fixed to a mounting portion 1A protruding below the structure 1 via a fixing material 8. That is, the fixing material 8 includes a base plate 8A that is applied to the bottom surface 1a of the mounting portion 1A from below, and a plurality of reinforcing bars 8B that are raised from the base plate 8A and embedded in the structure 1. The upper flange plate 6 is bolted to the base plate 8A.

  The second seismic isolation bearing portion b has a lower bearing member 9 having a cylindrical cylinder portion 11 that opens upward, and a state in which tilting (rotation about the horizontal axis) is possible with respect to the lower bearing member 9. The upper bearing member 10 having the piston portion 12 fitted in the cylinder portion 11 and the elastic member 13 enclosed and installed in the cylinder portion 11 while supporting the piston portion 12 are configured. The elastic member 13 is formed of a slightly thick elastomer (rubber plate) and is housed in the cylinder portion 11 in a sealed state. In other words, the second seismic isolation bearing part b has a pin support structure in which the lower bearing member 9 and the upper bearing member 10 can be freely tilted (rotated) by the thickness change (elastic deformation) of the elastomer 13. .

  The lower support member 9 includes a base plate 14 with which the cylinder portion 11 is integrated, and a plurality of reinforcing bars 15 depending downward from the base plate 14. The base plate 14 is mounted on a self-leveler 17 that is placed and supported on the upper surface of the support pile 2 made of a steel pipe pile 16 that is buried in the soil, and the rebar 15 is attached to a concrete portion 16 a that fills the steel pipe pile 16. Buried.

  The upper bearing member 10 includes a mounting flange 18 that is bolted to the lower flange plate 7 of the first seismic isolation bearing portion a, and a piston portion 12 that is integrated on the lower side thereof. The piston portion 12 includes a sealed disc portion 12a that is fitted inside the cylinder portion 11 so as to be capable of relative rotational movement, and a piston main body portion 12b that has an outer diameter slightly smaller than the inner diameter of the cylinder portion 11, and is a sealed disc. On the outer periphery of the lower end portion of the portion 12a, an O-ring 19 is provided for closely contacting the cylinder portion 11 and preventing the elastic member 13 from sticking out. As a means for fitting the piston portion 12 into the cylinder portion 11 so as to be relatively rotatable, the diameter of the cylindrical outer peripheral surface of the piston portion 12 is slightly smaller than the inner diameter of the cylinder portion 11 to form a very small gap. And means for forming the outer peripheral surface of the piston portion 12 as a part of a spherical surface.

  In the structure in which the structure 1 is seismically isolated using the seismic isolation device A having the above-described structure, when the earthquake occurs, as shown in FIG. The lateral displacement is absorbed as shown in (b), and the second seismic isolation part (b) is absorbed by being swung (rotated) as indicated by an arrow c. Accordingly, no force acts on the first seismic isolation bearing part a having the laminated rubber structure in the tilt direction, and the predetermined seismic isolation performance can be exhibited at all times, and the second seismic isolation bearing part b has A force in a tilt direction suitable for this is applied, and a predetermined seismic isolation performance can be exhibited. As a result, not only the roll but also the deformation in the tilt direction can be absorbed without difficulty, and the seismic isolation bearing device A having better seismic isolation performance can be realized.

  Further, as shown in FIG. 4, when the vertical projected area of the laminate 5 at the time of the maximum allowable lateral displacement of the first seismic isolation bearing portion a is Vmin and the area of the elastic member 13 is S, S ≧ Vmin. The relationship is set to hold. Due to this relationship, the load-bearing condition as the seismic isolation bearing device A is maintained within a predetermined good range regardless of the magnitude of shaking due to an earthquake or the like.

  The seismic isolation bearing device A can be used as shown in FIG. That is, a lower structure 30 supported by the ground 20 in a state of being mounted on the support pile 2 is constructed, and a seismic isolation bearing is mounted on a column 31 such as a column or a polygon that is erected from the lower structure 30. In this structure, the upper structure 32 (an example of the structure 1) is mounted via the device A. Even in this case, the upper structure 32 is seismically isolated so as to be capable of absorbing roll and tilt displacement with respect to the lower structure 30.

[Another Example]
A seismic isolation bearing device having a structure in which the second seismic isolation bearing b is positioned on the first seismic isolation bearing a may be used. The elastic member 13 may be synthetic rubber, natural rubber, or the like.

The structure of the seismic isolation bearing apparatus by Example 1 is shown, (a) is sectional drawing, (b) is a partial top view which shows the radial dimension of the principal part. Conceptual diagram showing a first example of use of the seismic isolation device of FIG. Side view of seismic isolation bearing device showing deformation during an earthquake Conceptual diagram showing the projected area when the first seismic isolation bearing is displaced most laterally Conceptual diagram showing a second example of use of the seismic isolation bearing device of FIG. Side view showing laminated rubber structure and lateral deformation Action diagram showing deformation when roll and tilt displacement occur in conventional laminated rubber

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mounted object 2 Mounting base 3 Elastic board 4 Hard board 5 Laminated body 6,7 Flange board 9 Lower support member 10 Upper support member 11 Cylinder part 12 Piston part 13 Elastic member a 1st seismic isolation part b 2nd seismic isolation Bearing part A Seismic isolation device

Claims (4)

A seismic isolation device for causing the mounting object to base isolation on the mounting table,
A first seismic isolation bearing capable of absorbing relative lateral displacement between the mounted object and the mounting table; and a second capable of absorbing a relative inclination between the mounted object and the mounting table. A seismic isolation device that is connected to a seismic isolation bearing in series.   The first seismic isolation bearing portion includes a laminated body in which a plurality of elastic plates and hard plates are alternately laminated, and each flange on the mounting object side and the mounting table side fixed to both ends in the stacking direction thereof. The seismic isolation bearing device according to claim 1, comprising a plate.   The second seismic isolation bearing portion includes a lower bearing member having a cylindrical cylinder portion that opens upward, and a piston portion that is fitted into the cylinder portion in a state in which the second bearing member can be inclined and moved relative to the lower bearing member. 3. The seismic isolation bearing device according to claim 1, further comprising: an upper support member having an elastic member that is sealed in the cylinder portion so as to support the piston portion. 4. The seismic isolation bearing device according to any one of claims 1 to 3, wherein the first seismic isolation bearing is disposed on the second seismic isolation bearing.

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