JP5577147B2 - Isolation structure - Google Patents

Description

  The present invention relates to a vibration isolating structure in which soft plates and hard plates are alternately laminated, and particularly relates to a vibration isolating structure that suppresses buckling during shear deformation.

  In order to reduce the horizontal excitation force that acts on structures such as buildings due to earthquakes, etc., the structure is supported by a vibration-isolating structure in which soft plates and hard plates are alternately stacked in the vertical direction. (For example, refer to Patent Document 1).

JP 2001-140977 A

In this type of vibration isolation structure, a flange member for attachment is bonded to the upper and lower portions of a laminated rubber body in which soft plates and hard plates are alternately laminated.
Since the vibration isolation structure is subjected to horizontal deformation when subjected to a horizontal excitation force, a large shearing force acts between the laminated rubber body and the flange member. For this reason, the durability of the bonded portion between the laminated rubber body and the flange member is important.

For example, there may be a case where water touches the lower part of the seismic isolation structure, and water enters the bonding portion from the outer peripheral side end of the laminated rubber main body to reduce the adhesive force between the laminated rubber main body and the flange member. Therefore, it is necessary to devise a technique for suppressing the decrease in the adhesive force.
When the adhesive force between the laminated rubber body and the flange member is reduced, the laminated rubber body and the flange member are separated from each other during shear deformation, and the seismic isolation structure does not function.

  Conventionally, as shown in FIG. 4, the central portion 102 of the flange member 100 is processed one step higher than the outer peripheral side of the flange, and the laminated rubber body 104 is bonded to the raised central portion 102. The rubber 106 covering the outer peripheral surface is extended to the outer peripheral portion 108 that is one step lower than the central portion 102.

  Thus, the laminated rubber main body 104 can be made longer by taking a longer distance from the end of the rubber 106 covering the laminated rubber main body 104 and the flange member 100 than the outer peripheral side of the flange to cover the bonded surface. It becomes difficult for water to reach the bonding surface between the base member and the flange member 100, and the durability of the seismic isolation structure can be improved.

  By the way, the vibration-isolating structure undergoes shear deformation in the horizontal direction as shown by the solid line in FIG. 4 when subjected to the horizontal excitation force (note that the two-dot chain line is the normal shape), but at the same time a large vertical load Therefore, when a large shear deformation is received in a state where a large vertical load is applied, the ends of the hard plates 110 (only shown below in FIG. 4) on both ends in the vertical direction are bent and deformed to support the load. May not be possible. In a base-isolated structure, the state where it becomes impossible to support such a vertical load is called “buckling”.

  The end of the hard plate 110 is bent and deformed because, as shown in FIG. 4, when the laminated rubber body 104 undergoes a large shear deformation, a space is formed below the hard plate 110 and the load cannot be supported. is there. In addition, although illustration is abbreviate | omitted, the bending deformation is similarly caused in the hard plate 110 on the upper side.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a seismic isolation structure having improved buckling resistance while ensuring durability.

This invention is made | formed in view of the said fact, Comprising: The invention of Claim 1 has a hard layer which has multiple rigidity, rigidity lower than the said hard layer , and has viscoelastic property. A main body in which soft layers are alternately laminated in the vertical direction, a covering material that covers the outer periphery of the main body, and a surface that is fixed to the upper and lower soft layers of the main body, and a surface that is fixed to the soft layer is planar a pair of flange members formed on the formed on the surface of the side to be fixed to the soft layer of the flange member so as to surround the main body, the covering material is secured enters the end of the body horizontal And an annular groove for sandwiching a part of the covering material between the flange member and the hard layer closest to the flange member when shear-deformed in a direction .

Next, the operation of the seismic isolation structure according to claim 1 will be described.
The seismic isolation structure according to claim 1 is disposed, for example, between a building and a building foundation, and one flange member is fixed to the building and the other flange member is fixed to the building foundation.
When the building to which the seismic isolation structure is applied in this way moves relative to the building foundation in the horizontal direction (vibrates) due to an earthquake or the like, the body undergoes shear deformation (elastic deformation), and a part of the energy of vibration Absorbs and exhibits resilience.

  When the horizontal relative movement amount between the building and the building foundation is relatively small, the main body shears and deforms, but the outer peripheral surface does not come into contact with the flange member, but when the relative movement amount increases, the outer periphery of the main body The covering material covering the surface comes into contact with the flange member, and the load support area increases with respect to the flange portion. The soft layer and the covering material are sandwiched between the end of the rigid plate closest to the flange member and the flange member, and the bending deformation of the end due to the load is suppressed, so that the seismic isolation structure is less likely to buckle. , Buckling resistance is improved.

  Further, in this seismic isolation structure, the end portion of the covering material enters and adheres to the annular groove formed at a position away from the outer periphery of the laminated rubber main body in the radial direction, so that the main body and the flange member are bonded. The distance to the surface is sufficiently secured, and it is difficult for water to enter the bonding surface between the main body and the flange member, and the durability of the seismic isolation structure is sufficiently secured.

  According to a second aspect of the present invention, in the seismic isolation structure according to the first aspect, an end portion of the covering material is fixed to the annular groove on a radially inner side, and the end portion is disposed on a radially outer side. A sealing material covering the boundary with the flange member is fixed.

Next, the operation of the seismic isolation structure according to claim 2 will be described.
In the seismic isolation structure according to claim 2, the end portion of the covering material is fixed to the radially inner portion of the annular groove, the sealing material is fixed to the radially outer portion, and the end portion of the covering material and the flange member By covering the boundary portion with the sealing material, the sealing material is arranged on the upstream side of the water intrusion path (bonding surface between the coating material and the flange member), and it is difficult for water to enter from the end side of the coating material. Thus, the durability can be further improved.

  As described above, since the seismic isolation structure according to claim 1 has the above-described configuration, it has an excellent effect that the buckling resistance can be improved while ensuring the durability.

  Moreover, since the seismic isolation structure of Claim 2 was set as said structure, durability can further be improved.

It is a longitudinal cross-sectional view at the normal time of the seismic isolation structure which concerns on the 1st Embodiment of this invention. It is a longitudinal cross-sectional view at the time of the shear deformation of the seismic isolation structure which concerns on 1st Embodiment. It is sectional drawing of the principal part of the seismic isolation structure which concerns on 2nd Embodiment. It is sectional drawing at the time of the shear deformation of the conventional seismic isolation structure.

[First Embodiment]
FIG. 1 shows a seismic isolation structure 10 according to a first embodiment of the present invention. The seismic isolation structure 10 is arrange | positioned, for example between the building foundation 12 which is an example of a supporting member, and the bottom part of the building 14 which is an example of a supported member.

  The seismic isolation structure 10 has a laminated rubber body 20 configured by alternately laminating a plurality of internal steel plates 16 and rubber plates 18 each formed in a disk shape in the vertical direction. In the present embodiment, all the internal steel plates 16 have the same thickness, and all the rubber plates 18 have the same thickness.

The internal steel plate 16 and the rubber plate 18 are firmly bonded to each other by vulcanization adhesion (or by an adhesive) so that they are not inadvertently separated or misaligned. When the laminated rubber body 20 receives a horizontal shearing force, it elastically shears and deforms.
Therefore, when the building 14 is relatively moved (vibrated) in the horizontal direction with respect to the building foundation 12 due to an earthquake or the like, the seismic isolation structure 10 is elastically sheared as a whole and absorbs energy of this vibration.

  Here, as described above, by alternately laminating the internal steel plates 16 and the rubber plates 18, even when a load acts in the laminating direction, the compression of the laminated rubber body 20 (that is, compression of the rubber plates 18) is suppressed. Has been. Accordingly, the rubber plate 18 can be sufficiently sheared to absorb energy and exhibit a restoring force.

The laminated rubber body 20 further includes a covering material 22 that covers the inner steel plate 16 and the outer end face of the rubber plate 18 from the periphery.
The covering material 22 is preferably made of a material such as rubber having better weather resistance than the rubber plate 18, and rain (water) or light is externally applied to the internal steel plate 16 and the rubber plate 18 by the covering material 22. It does not act directly, and the internal steel plate 16 and the rubber plate 18 are prevented from being deteriorated by oxygen, ozone, ultraviolet rays or the like. The covering material 22 may be formed of the same material as that of the rubber plate 18 in some cases.

A flange member 24 made of a steel plate or the like formed in a disk shape having a larger diameter than the laminated rubber body 20 and a certain thickness is added to the rubber plates 18 at both ends (upper and lower ends) of the laminated rubber body 20 in the lamination direction. Sulfur bonded. In addition, as for the flange member 24, the surface by which the rubber plate 18 of the laminated rubber main body 20 is adhere | attached is a plane.
The laminated rubber body 20 is disposed at the center of the flange member 24, and the flange member 24 has a larger diameter than the laminated rubber body 20 on the surface of the laminated rubber body 20 to which the rubber plate 18 is bonded. The annular groove 26 is formed coaxially with the laminated rubber body 20. The annular groove 26 can be easily processed with an end mill or the like.

  The covering material 22 covering the outer peripheral surface of the laminated rubber main body 20 extends slightly toward the outer peripheral direction of the flange member 24 and then enters the annular groove 26, and the rubber plate of the laminated rubber main body 20 of the flange member 24. It is bonded to the surface of the side where 18 is bonded and the entire groove wall surface of the annular groove 26.

  A plurality of bolt holes 28 are formed in the flange member 24. By tightening a nut 32 on a bolt 30 through which the bolt holes 28 are inserted, the upper flange member 24 is placed on the bottom of the building 14 and the lower side. The flange member 24 is fixed to the building foundation 12.

  Incidentally, the seismic isolation structure 10 of the present embodiment has an outer diameter of the laminated rubber body 20 of 600 to 1600 mm, a diameter of the flange member 24 of 800 to 1900 mm, a thickness of the flange member 24 of 30 to 45 mm, and a depth of the annular groove 26. The width of the annular groove 26 is about 5 mm, but the present invention is not limited to these dimensions.

(Function)
When the building 14 to which the seismic isolation structure 10 is applied in this manner is moved relative to the building foundation 12 in the horizontal direction (vibrated) due to an earthquake or the like, the laminated rubber body 20 undergoes shear deformation (elastic deformation). In addition to absorbing a part of the energy of this vibration, it exhibits a restoring force.

  Here, since the laminated rubber body 20 of the present embodiment has a circular horizontal cross section, there is no directionality in deformation. Therefore, the laminated rubber main body 20 can be elastically deformed and absorb this energy regardless of the vibration in any direction in the horizontal direction.

  By the way, when the horizontal relative movement amount between the building 14 and the building foundation 12 increases, as shown in FIG. 2, the lower end side of the laminated rubber body 20 in the direction in which the building 14 is displaced (direction of arrow A). A portion of the covering material 22 covering the outer peripheral surface of the inner surface of the inner steel plate 16 disposed on the lowermost side is in contact with the upper surface of the flange member 24 on the base side to increase the load support area. Since the rubber plate 18 and the covering material 22 are sandwiched between the base portion and the flange member 24 on the base side and the end portion is supported from the lower side, the end portion of the internal steel plate 16 is bent by a load acting from above. Deformation, that is, buckling of the seismic isolation structure 10 is suppressed.

As shown in FIG. 2, a part of the covering material 22 is also in contact with the flange member 24 on the upper end side of the laminated rubber body 20, and the side opposite to the arrow A direction side of the inner steel plate 16 disposed on the uppermost side. Since the rubber plate 18 and the covering material 22 are sandwiched between the end portion of the steel plate and the flange member 24 and the end portion is supported from the upper side, the end portion of the internal steel plate 16 is prevented from being bent and deformed. .
In this way, the seismic isolation structure 10 of the present embodiment is improved in buckling resistance.

  Moreover, in the seismic isolation structure 10 of this embodiment, since the edge part of the coating | covering material 22 penetrates into the annular groove 26 formed in the position away from the outer periphery of the laminated rubber main body 20 to the radial direction outer side, and is adhere | attached. Similarly to the conventional seismic isolation structure, a sufficient distance from the end of the covering material 22 to the bonding surface between the laminated rubber main body 20 and the flange member 24 is secured, and the laminated rubber main body 20 and the flange member 24 It is difficult for water to enter the bonding surface, and the durability of the seismic isolation structure 10 is sufficiently ensured.

  In addition, since the flange member 24 of the present embodiment has a constant thickness as a whole, for example, it is only necessary to cut out a steel plate into a circle and then process the annular groove 26 with an end mill or the like. Compared to the flange member, the number of processed parts is small, and manufacturing is easy.

[Second Embodiment]
Next, 2nd Embodiment of the seismic isolation structure 10 is described according to FIG. In addition, the same code | symbol is attached | subjected to the same structure as 1st Embodiment, and the description is abbreviate | omitted.
As shown in FIG. 3, the annular groove 26 of the flange member 24 of the present embodiment is formed wider than the annular groove 26 of the first embodiment, and the end portion of the covering material 22 is located inside the annular groove 26. An elastic sealing material (caulking material; a known material such as silicon rubber can be applied) 34 is fixed to the radially inner side.

  Therefore, in the present embodiment, the end portion of the covering material 22 is covered with the elastic sealing material 34, and has a structure that is more resistant to water ingress than the first embodiment, further improving durability. Can be made.

[Other Embodiments]
In the above embodiment, a steel plate is used as the hard layer and a rubber plate is used as the soft layer. However, the hard layer may be made of a material other than steel, and the soft layer may be made of a material other than rubber. Well, all materials used for conventional seismic isolation structures are applicable.

  In the above embodiment, the thicknesses of the plurality of internal steel plates 16 are all constant, but the thickness of the internal steel plate 16 close to the flange member 24 may be formed thicker than the other internal steel plates 16.

  In the above-described embodiment, the thickness of the flange member 24 is constant. However, at least the surface to which the laminated rubber main body 20 is bonded may be planar, and the opposite surface may not be planar.

10 Seismic isolation structure 16 Internal steel plate (hard layer)
18 Rubber plate (soft layer)
20 Laminated rubber body (main body)
22 Coating material 24 Flange member 26 Annular groove 34 Sealing material

Claims (2)

A main body in which a plurality of rigid layers and a soft layer having lower rigidity than the hard layer and having viscoelastic properties are alternately stacked in the vertical direction;
A covering material covering the outer periphery of the main body;
A pair of flange members each fixed to the upper and lower soft layers of the main body, and the surface to be fixed to the soft layer is formed in a planar shape;
Formed on the surface of the flange member to be fixed to the soft layer so as to surround the main body, and when the end of the covering material enters and is fixed, and the main body is sheared in the horizontal direction, the covering is formed. An annular groove for sandwiching a part of the material between the flange member and the hard layer closest to the flange member ;
A base-isolated structure.   The end portion of the covering material is fixed to the annular groove on the radially inner side, and a sealing material that covers a boundary between the end portion and the flange member is fixed on the radially outer side. Seismic isolation structure.

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