JP6532712B2 - Seismic isolation structure - Google Patents

Description

  The present invention relates to a seismic isolation structure.

  A seismic isolation structure in which rubber and steel plates are alternately stacked is disclosed (see Patent Document 1). At the upper and lower ends of the seismic isolation structure, mounting flanges are provided for installing the seismic isolation structure on a building or a foundation.

Japanese Patent Application Laid-Open No. 10-68442

  In the seismic isolation structure, while having resistance to vertical load based on the weight of a building etc., to reduce the acceleration by shear deformation to correspond to the shear force input in the horizontal direction at the time of earthquake occurrence etc. It has been demanded. During this shear deformation, a bending moment acts on the seismic isolation structure, but the bending moment is usually maximum near the mounting flange.

  An object of this invention is to suppress the bending moment which acts on the attachment flange vicinity of a laminated body, and to improve durability.

The seismic isolation structure according to claim 1 is configured by alternately laminating a soft plate made of an elastic body and a rigid plate, and has at least one layer of the soft plate and at least one layer of the rigid plate. The laminated body which has the both ends which are respectively fixed to the pair of installation flanges, and the central part which connects the both ends together, the shear elastic modulus of the elastic body which constitutes the soft board of the both ends is constant And the shear modulus of elasticity of the elastic body constituting the soft plate at the central portion is also constant, and the shear modulus of the soft plates at the both end portions is higher than the shear modulus of the soft plate at the central portion high, the thickness of the soft plate is constant at both ends, and also a constant thickness of the soft plate in the central portion, the thickness of the soft plate in the end portions, of the soft plate in the central portion smaller than the thickness, the two The average thickness of the rigid plate in the section is greater than the average thickness of the rigid plate in the central portion.

In this seismic isolation structure, the shear modulus of elasticity of the elastic body constituting the soft plate at both ends of the laminate is constant, and the shear modulus of elasticity of the elastic body constituting the soft plate at the central portion of the laminate is also constant, The shear modulus of the soft plate at both ends is higher than the shear modulus of the soft plate at the central portion. In addition, the thickness of the soft plate at both ends is constant, and the thickness of the soft plate at the center is also constant, and the thickness of the soft plate at both ends is smaller than the thickness of the soft plate at the center. That is, the shear rigidity in the vicinity of the pair of mounting flanges in the laminate is high. Therefore, the bending moment acting in the vicinity of the mounting flange is suppressed at the time of horizontal shear deformation at the time of earthquake occurrence or the like.

  The invention of claim 2 is the seismic isolation structure according to claim 1, wherein the number of layers of the soft plate and the rigid plate at the both end portions is 10 to 30% of the total number of layers.

  In this seismic isolation structure, since the number of layers of the soft plate and the rigid plate at both ends is 10 to 30% of the total number of layers, the laminate and its periphery at the time of horizontal shear deformation at the time of earthquake occurrence etc. The shear strain at the central portion can be suppressed while suppressing the interference with the portion.

  The invention of claim 3 is the seismic isolation structure according to claim 1, wherein the number of layers of the soft plate and the rigid plate at the both end portions is 2 to 10, respectively.

  In this seismic isolation structure, since the number of layers of the soft plate and the rigid plate at both ends is 2 to 10 respectively, interference between the laminate and its surrounding area at the time of horizontal shear deformation at the time of earthquake occurrence etc. Can be suppressed while suppressing shear strain in the central portion.

The invention according to claim 4 is the seismic isolation structure according to any one of claims 1 to 3, wherein a shear elastic modulus of the elastic body constituting the soft plate at the both end portions is the central portion. The elastic modulus of the elastic body constituting the soft plate is 1.1 to 2 times the shear modulus .

In this seismic isolation structure, since the shear elastic modulus of the elastic body constituting the soft plate at both ends is 1.1 to 2 times the shear elastic modulus of the elastic body constituting the soft plate at the central portion, At the time of horizontal shear deformation in time or the like, it is possible to suppress the shear strain in the central portion while suppressing the interference between the laminate and the peripheral portion thereof.

  ADVANTAGE OF THE INVENTION According to the seismic isolation structure which concerns on this invention, the outstanding effect that durability can be improved by suppressing the bending moment which acts on the attachment flange vicinity of a laminated body is acquired.

It is a sectional view showing a seismic isolation structure concerning this embodiment. It is an expanded sectional view showing a seismic isolation structure concerning this embodiment. It is a front view which shows the deformation state of the seismic isolation structure which concerns on this embodiment.

  Hereinafter, a mode for carrying out the present invention will be described based on the drawings. In FIG. 1, the seismic isolation structure 10 according to the present embodiment has a stacked body 20. The laminate 20 is configured by alternately laminating soft plates 12 and 22 made of an elastic body and rigid plates 14 and 24. The laminate 20 has at least one layer of the soft plate 12 and at least one layer of the rigid plate 14 and connects both end portions 20A fixed to the pair of mounting flanges 16 and 18 and both end portions 20A. And a central portion 20B. The laminate 20 is fixed between the pair of mounting flanges 16 and 18, for example, by vulcanization bonding. The soft plates 12 and 22 and the rigid plates 14 and 24 are both formed in a circular shape and have the same outer diameter. For example, rubber or an elastomer is used for the elastic body constituting the soft plates 12 and 22. The rigid plates 14 and 24 are made of metal such as steel and stainless steel.

  The average shear modulus of elasticity of the elastic members constituting the soft plates 12 and 22 and the thickness of the soft plates 12 and 22 at both end portions 20A in the laminating direction (arrow V direction) of the laminate 20 and the central portion 20B located therebetween And the thickness of the rigid plates 14, 24 are different from one another. Specifically, the average shear elastic modulus of the elastic body constituting the soft plate 12 at both end portions 20A is higher than the average shear elastic modulus of the elastic body constituting the soft plate 22 of the central portion 20B. It is 1.1 to 2 times the average shear modulus of the elastic body to constitute. Further, the average thickness of the soft plates 12 at the end portions 20A is smaller than the average thickness of the soft plates 22 at the central portion 20B.

  The shear modulus is a static shear modulus according to JIS K 6386, or a static shear modulus according to JIS K 6254. Moreover, when the plate thickness of each soft board 22 in both ends 20A is uniform, an average thickness is a simple average of the board thickness of all the soft boards 22 contained in both ends 20A. When the plate thickness of a certain soft plate 22 is nonuniform, the average value of the plate thicknesses of the soft plate 22 is obtained, and then the plate thicknesses of all the soft plates 22 included in the both end portions 20A are averaged.

In the illustrated example, the thickness of the soft plate 12 at both ends 20A is constant, and the thickness of the soft plate 22 at the central portion 20B is also constant. That is, assuming that the thickness of the soft plate 12 is T12 and the thickness of the soft plate 22 is T22, T12 <T22. Further, the shear modulus of elasticity of the soft plates 12 at both end portions 20A is constant, and the shear modulus of elasticity of the soft plates 22 at the central portion 20B is also constant. As a reference example, the thickness and shear modulus of elasticity of the soft plates 12 and 22 may not be constant.

  In addition, the rigid plate 14 at both ends 20A is thicker than the rigid plate 24 at the central portion 20B. That is, assuming that the thickness of the rigid plate 14 is T14 and the thickness of the rigid plate 24 is T24, then T14> T24.

  Furthermore, the number of layers of the soft plate 12 and the rigid plate 14 at both end portions 20A is 10 to 30% of the total number of layers. In terms of specific numerical values, the number of layers of the soft plate 12 and the rigid plate 14 at both end portions 20A is, for example, 2 to 10, respectively. The number of layers of the soft plate 12 and the rigid plate 14 at both ends 20A means the total number of layers of the soft plate 12 and the rigid plate 14 at one and the other of the both ends 20A. The total number of layers means the total number of layers of the soft plates 12 and 22 in the laminate 20 or the total number of layers of the rigid plates 14 and 24 in the laminate 20.

  Although illustration is abbreviate | omitted, as an example of the laminated body 20, the number of layers of the soft board 12 in both-ends 20A can be 7 layers, and the number of layers of the soft board 22 in the center part 20B can be 18 layers. Further, the number of layers of the rigid plate 14 at the both end portions 20A can be seven, and the number of layers of the rigid plate 24 at the central portion 20B can be seventeen. In this case, since the number of layers of the soft plates 22 in the central portion 20B is one more than the number of layers of the rigid plates 24, the soft plates 22 are disposed at both ends in the stacking direction of the central portion 20B.

  Regarding the thickness, the thickness of the soft plate 12 can be 4.9 mm (constant), and the thickness of the soft plate 22 can be 6.5 mm (constant). Further, the thickness of the rigid plate 14 can be 4.4 mm, and the thickness of the rigid plate 24 can be 3.1 mm.

  As shown in FIG. 3, the seismic isolation structure 10 is fixed to the upper structure 26 such as a building by the mounting flange 16 and to the lower structure 28 such as the foundation by the mounting flange 18. For example, a bolt 30 is used for fixing.

(Action)
The present embodiment is configured as described above, and the operation thereof will be described below. In FIG. 3, when the upper structural body 26 moves relative to the lower structural body 28 in the horizontal direction (the direction of the arrow H) at the time of an earthquake or the like, a horizontal shear force is input to the laminated body 20, and the laminated body 20 is sheared horizontally. As shown in FIG. 1 and FIG. 2, in the seismic isolation structure 10 according to the present embodiment, shear rigidity of both ends 20A of the laminated body 20 located near the pair of mounting flanges 16 and 18 by the above configuration And both ends 20A are difficult to fall in the horizontal direction. Therefore, at the time of horizontal shear deformation of the laminated body 20, a bending moment acting on the vicinity of the mounting flanges 16 and 18 is suppressed.

  In addition, since the number of layers of the soft plate 12 and the rigid plate 14 at the both end portions 20A is 10 to 30% of the total number of layers, the laminate 20 and its peripheral portion at the time of horizontal shear deformation of the laminate 20, For example, while suppressing the interference with the bolt 30 (FIG. 3), the shear strain of the central portion 20B can be suppressed. Since the interference between the laminate 20 and its peripheral portion is suppressed, there is no need to take measures such as thinning the mounting flanges 16 and 18 in order to prevent the laminate 20 from contacting the bolt 30.

  In addition, this effect sets the number of layers of the soft plate 12 and the rigid plate 14 at both end portions 20A to 2 to 10 layers, respectively, or the average shear elastic modulus of the elastic body constituting the soft plates 12 at both end portions 20A. It can also be obtained by setting it to 1.1 to 2 times the average shear modulus of the elastic body constituting the soft plate 22 of the central portion 20B.

  Thus, according to the seismic isolation structure 10 which concerns on this embodiment, the bending moment which acts on the attachment flanges 16 and 18 vicinity of the laminated body 20 can be suppressed, and durability can be improved. Moreover, the cost is equal to that of the conventional product. On the other hand, when the durability is set equal to that of the conventional product, the cost can be reduced. In the conventional product, in the laminate, the average shear modulus and the average thickness of the elastic members constituting the soft plate are constant, and the average thickness of the rigid plate is constant (not shown). ).

[Other embodiments]
As mentioned above, although an example of the embodiment of the present invention was described, the embodiment of the present invention is not limited to the above, and besides the above, it can be variously modified and carried out in the range which does not deviate from the main point Of course there is one.

  The mounting flanges 16 and 18 may be configured to be retrofitted to the laminate 20 using bolts or the like. In other words, the seismic isolation structure 10 may or may not have the mounting flanges 16 and 18.

  Although the number of layers of the soft plate 12 and the rigid plate 14 at both end portions 20A is 10 to 30% of the total number of layers, the numerical range is not limited to this. The number of layers of the soft plate 12 and the rigid plate 14 at both ends 20A is 2 to 10 respectively, and the average shear modulus of elasticity of the elastic body constituting the soft plate 12 at both ends 20A is the soft plate of the central portion 20B The same applies to the point which is 1.1 to 2 times the average shear elastic modulus of the elastic body constituting 22.

DESCRIPTION OF SYMBOLS 10 ... Seismic isolation structure, 12 ... Soft board, 14 ... Rigid board, 16 ... Mounting flange, 18 ... Mounting flange, 20 ... Laminated body, 20A ... Both ends, 20B ... Central part, 22 ... Soft board, 24 ... Rigidity plates, T12 ... average thickness of the soft plate, T14 ... rigid plate average thickness of, T22 ... soft plate average thickness of the average thickness of the T24 ... rigid plate

Claims (4)

Soft plates made of an elastic body and rigid plates are alternately stacked, and both ends have at least one layer of the soft plates and at least one layer of the rigid plates and are respectively fixed to a pair of mounting flanges A laminate having a portion and a central portion connecting the two end portions,
The shear modulus of elasticity of the elastic body constituting the soft plate at both ends is constant, and the shear modulus of elasticity of the elastic body constituting the soft plate at the central portion is also constant.
The shear modulus of the soft plates at the two end portions is higher than the shear modulus of the soft plates at the central portion,
The thickness of the soft plate at both ends is constant, and the thickness of the soft plate at the central portion is also constant,
The thickness of the soft plate at said end portion is smaller than the thickness of the soft plate in the central portion,
The seismic isolation structure in which the average thickness of the said rigid board in the said both ends is larger than the average thickness of the said rigid board in the said center part.   The seismic isolation structure according to claim 1, wherein the number of layers of the soft plate and the rigid plate at the both end portions is 10 to 30% of the total number of layers.   The seismic isolation structure according to claim 1, wherein the number of layers of the soft plate and the rigid plate at the both end portions is 2 to 10, respectively. The shear modulus of elasticity of the elastic body constituting the soft plate at the both end portions is 1.1 to 2 times the shear modulus of elasticity of the elastic body constituting the soft plate of the central portion. The seismic isolation structure according to any one of Items 3.

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