Seismic isolation device and seismic isolation structure equipped therewith

Abstract

To provide a simple base isolation device capable of preventing buckling when undergoing large deformation and to provide a base isolation structure provided with the base isolation device.SOLUTION: A base isolation device 10 comprises a multi-stage laminated rubber bearing 18 made up of: laminated rubber 22 which is installed in a base isolation layer 16 between a superstructure 12 and a substructure 14 and arranged in stages in a vertical direction; and a connection member 32 which is arranged between upper and lower laminated rubber 22 and connects the upper and lower laminated rubber 22. The base isolation device also has a buckling prevention bearing 20 which is installed at a distance from the multi-stage laminated rubber bearing 18 in a horizontal direction. The buckling prevention bearing 20 has a slide section 36 which allows the connection member 32 to come into contact with and to slide on the same when the multi-stage laminated rubber bearing 18 undergoes deformation of predetermined magnitude or more.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a seismic isolation device and a seismic isolation structure provided with the same.

Background Art

[0002] Conventionally, seismic isolation buildings provided with a seismic isolation layer have been known (for example, refer to Patent Document 1). In recent years, the seismic motion to be considered in design has tended to increase, and there is a risk that a seismic isolation building may collide with a retaining wall in the conventional design. In order to avoid direct collision with the retaining wall, much development of fail-safe technologies such as providing a collision buffer material has been carried out. On the other hand, there is also a concept of performing a design to expand the seismic isolation clearance and allowing large deformation of the seismic isolation layer.

[0003] In order to allow large deformation of the seismic isolation layer, a bearing material capable of coping with large deformation is required. As a commercially available laminated rubber for seismic isolation, there is a product with a rubber thickness of 320 mm, and considering a deformation of 400%, this product can allow a deformation up to 1280 mm. In the case of a sliding bearing, it is necessary to install a sliding plate within the movable range of the bearing. The sliding plate is generally manufactured in a factory and transported to the construction site, and the size of the sliding plate must be 2400 mm or less due to transportation restrictions. Therefore, if the cross-sectional dimension of the column above the bearing is 600 mm, the maximum sliding displacement is 900 mm, and large deformations exceeding this cannot be coped with.

[0004] On the other hand, in order to cope with large deformation, a multi-stage laminated rubber bearing in which laminated rubbers are laminated in two upper and lower stages and the deformation amount is doubled is known (for example, refer to Patent Document 2). As shown in FIG. 3(1), this multi-stage laminated rubber bearing 1 is provided in a seismic isolation layer 4 between an upper structure 2 and a lower structure 3, and includes laminated rubbers 5 arranged in two upper and lower stages, and a connecting plate 6 arranged between the upper and lower laminated rubbers 5 and connecting them. In such a configuration, as shown in FIG. 3(2), there is a possibility that the laminated rubber 5 may buckle due to the load of the vertical axial force during large deformation. Therefore, several devices have been proposed to avoid buckling (for example, refer to Patent Document 3).

[0005] The apparatus described in Patent Document 3 suppresses vertical displacement of the laminated rubber due to the weight of the superstructure by arranging multiple multi-stage laminated rubber bearings in parallel, and also includes a parallel maintenance means to allow the lower laminated rubber to deform parallel without buckling. The parallel maintenance means consists of first and second pantograph mechanisms with a sliding mechanism. The first pantograph mechanism is provided on a vertical plane passing through the X direction of the X direction, which is one of the X and Y directions that are mutually orthogonal in the horizontal plane, and the second pantograph mechanism is provided on a vertical plane passing through the Y direction. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 9-242382 [Patent Document 2] Japanese Patent Application Publication No. 7-207764 [Patent Document 3] Japanese Patent Publication No. 2003-287083 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, the conventional device described in Patent Document 3 above has the problem of being a very complex and expensive device configuration because it requires a pantograph mechanism with a sliding mechanism in both the X and Y directions. For this reason, there was a need for a simple seismic isolation device that could prevent buckling during large deformations.

[0008] The present invention has been made in view of the above, and aims to provide a simple seismic isolation device that can prevent buckling during large deformations, and a seismic isolation structure equipped therewith. [Means for solving the problem]

[0009] To solve the above-mentioned problems and achieve the objective, the seismic isolation device according to the present invention is a seismic isolation device provided in a seismic isolation layer between a superstructure and a substructure, comprising a multi-stage laminated rubber bearing consisting of laminated rubber arranged in multiple stages in the vertical direction and a connecting member positioned between the upper and lower laminated rubbers to connect the upper and lower laminated rubbers, further comprising a buckling prevention bearing provided at a position horizontally separated from the multi-stage laminated rubber bearing, wherein the buckling prevention bearing is provided with a sliding portion that can be contacted and slid by the connecting member when the multi-stage laminated rubber bearing deforms beyond a predetermined size.

[0010] Furthermore, another seismic isolation device according to the present invention is characterized in that, in the above-described invention, the buckling prevention bearing is arranged in a ring around the multi-stage laminated rubber bearing.

[0011] Furthermore, the seismic isolation structure according to the present invention is characterized by being equipped with the seismic isolation device described above. [Effects of the Invention]

[0012] The seismic isolation device according to the present invention is provided with a multi-stage laminated rubber bearing, which is provided in a seismic isolation layer between a superstructure and a substructure and comprises laminated rubber arranged in multiple stages in the vertical direction, and a connecting member provided between the upper and lower laminated rubbers to connect the upper and lower laminated rubbers. The seismic isolation device further comprises a buckling prevention bearing provided at a position horizontally separated from the multi-stage laminated rubber bearing, and the buckling prevention bearing is provided with a sliding portion that can be contacted and slid by the connecting member when the multi-stage laminated rubber bearing deforms beyond a predetermined size, thereby providing a simple seismic isolation device that can prevent buckling during large deformations.

[0013] Furthermore, according to another seismic isolation device of the present invention, the buckling prevention bearing is arranged in a ring around the multi-stage laminated rubber bearing, which has the effect of preventing buckling in response to large deformations in any direction.

[0014] Furthermore, the seismic isolation structure according to the present invention, by being equipped with the above-mentioned seismic isolation device, provides the effect of providing a simple seismic isolation structure that can prevent buckling during large deformations. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a side cross-sectional view showing an embodiment of the seismic isolation device and a seismic isolation structure equipped therewith according to the present invention. [Figure 2] Figure 2 is a plan cross-sectional view showing an embodiment of the seismic isolation device and a seismic isolation structure equipped therewith according to the present invention. [Figure 3] Figure 3 is a side cross-sectional view showing the behavior of a conventional two-layer laminated rubber bearing, where (1) is under normal conditions and (2) is during an earthquake. [Modes for carrying out the invention]

[0016] Embodiments of the seismic isolation device and seismic isolation structure equipped therewith according to the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to these embodiments.

[0017] As shown in Figures 1 and 2, the seismic isolation device 10 according to an embodiment of the present invention comprises a multi-stage laminated rubber bearing 18 and a buckling prevention bearing 20 provided on the seismic isolation layer 16 between the superstructure 12 and the substructure 14. The seismic isolation structure 100 according to this embodiment is a structure comprising a superstructure 12, a substructure 14, and the seismic isolation device 10.

[0018] The multi-stage laminated rubber bearing 18 is a bearing in which laminated rubber 22 is stacked in two (multi-stage) layers, upper and lower. The laminated rubber 22 is cylindrical in shape, with multiple layers of rubber 24 and steel plates 26 stacked in the vertical direction. Circular plates 28 and 30 are placed on the upper and lower end faces of the laminated rubber 22. The upper end plate 28 of the upper laminated rubber 22A is fixed to the lower surface of the superstructure 12. The lower end plate 30 of the lower laminated rubber 22B is fixed to the upper surface of the substructure 14.

[0019] The plate 30 at the lower end of the upper laminated rubber 22A and the plate 28 at the upper end of the lower laminated rubber 22B are connected via a connecting plate 32 (connecting member) disposed between the plates 30 and 28. Specifically, they are connected by bolts passed through bolt holes (not shown) formed in the plate 30, the connecting plate 32, and the plate 28, and fastening nuts screwed onto the bolts.

[0020] The connecting plate 32 is a steel plate with a rectangular planar shape, and horizontally projects in a flange shape radially outward from the outer edges of the plates 28 and 30 toward the outside in the radial direction of the plates 28 and 30.

[0021] The buckling prevention bearing 20 is disposed at a position horizontally separated from the multi-stage laminated rubber bearing 18 by a certain distance. This buckling prevention bearing 20 is coaxially and annularly disposed around the multi-stage laminated rubber bearing 18. By arranging it annularly, it can respond to displacements in any direction of the connecting plate 32. The lower part of the buckling prevention bearing 20 is fixed to the lower structure 14, and a sliding part 36 is provided on the upper surface of the top 34 of the buckling prevention bearing 20. The buckling prevention bearing 20 can be made of, for example, concrete or the like. In this way, the introduction cost can be reduced.

[0022] The sliding part 36 is a part where when the multi-stage laminated rubber bearing 18 is deformed beyond a predetermined size, the connecting plate 32 comes into contact and the lower surface of the connecting plate 32 becomes slidable. The sliding part 36 may be formed, for example, by attaching a friction material such as a low-friction friction plate with a low friction coefficient or a PTFE (polytetrafluoroethylene) sheet to the upper surface of the buckling prevention bearing 20. The installation height H of the sliding part 36 from the upper surface of the lower structure 14 is preferably set slightly lower than the installation height P of the connecting plate 32 so that the connecting plate 32 can slide on the sliding part 36 when the multi-stage laminated rubber bearing 18 is greatly deformed. For example, the installation height H of the sliding part 36 may be set about 5 mm lower than the installation height P of the connecting plate 32.

[0023] According to this embodiment, by arranging the laminated rubber 22 in two layers, one above the other, it is possible to double the amount of deformation compared to when the laminated rubber 22 is arranged in one layer. When the laminated rubber 22 is stacked in two layers, there is a concern that it may buckle under vertical load during large deformation. However, according to this embodiment, the connecting plate 32, which is displaced horizontally during large deformation, is supported so as to be movable by the sliding portion 36 of the top portion 34 of the buckling prevention support 20. Therefore, even during large deformation, the upper and lower laminated rubbers 22A and 22B of the connecting plate 32 deform parallel to each other without changing their height. For this reason, there is no risk of the laminated rubbers 22A and 22B buckling.

[0024] Furthermore, by installing a connecting plate 32 between the upper and lower laminated rubbers 22A and 22B, and installing buckling prevention bearings 20 around it, it is possible to prevent buckling of the laminated rubbers 22A and 22B during large deformations. Therefore, a simple seismic isolation device that can prevent buckling during large deformations can be provided.

[0025] In the above embodiment, the planar shape of the connecting plate 32 is rectangular and the planar arrangement of the buckling prevention bearings 20 is annular, but the present invention is not limited to this. The planar shape of the connecting plate 32 and the planar arrangement of the buckling prevention bearings 20 can be any shape as long as the connecting plate 32 can be supported by the buckling prevention bearings 20 when it undergoes large deformation.

[0026] Furthermore, although the above embodiment was described using the example of a multi-stage laminated rubber bearing 18 being a bearing in which laminated rubber 22 is stacked in two stages, upper and lower, the multi-stage laminated rubber bearing of the present invention is not limited to this, and may be a bearing in which laminated rubber 22 is stacked in three or more stages in the vertical direction. In this case, a connecting plate 32 provided between any of the laminated rubber 22 may be supported so as to be movable by the sliding portion 36 of the buckling prevention bearing 20 during large deformation.

[0027] As described above, the seismic isolation device according to the present invention is a seismic isolation device comprising a multi-stage laminated rubber bearing provided in a seismic isolation layer between a superstructure and a substructure, comprising laminated rubber arranged in multiple stages in the vertical direction, and a connecting member provided between the upper and lower laminated rubbers to connect the upper and lower laminated rubbers, and further comprising a buckling prevention bearing provided at a position horizontally away from the multi-stage laminated rubber bearing, wherein the buckling prevention bearing is provided with a sliding portion that can be contacted and slid by the connecting member when the multi-stage laminated rubber bearing deforms beyond a predetermined size, thereby providing a simple seismic isolation device that can prevent buckling during large deformations.

[0028] Furthermore, according to another seismic isolation device of the present invention, the buckling prevention bearing is arranged in a ring around the multi-stage laminated rubber bearing, so that buckling can be prevented in response to large deformations in any direction.

[0029] Furthermore, the seismic isolation structure according to the present invention is equipped with the above-mentioned seismic isolation device, and therefore provides a simple seismic isolation structure that can prevent buckling during large deformations. [Industrial applicability]

[0030] As described above, the seismic isolation device and seismic isolation structure equipped therewith are useful for seismic isolation structures equipped with a seismic isolation layer, and are particularly suitable for easily preventing buckling during large deformations. [Explanation of Symbols]

[0031] 10 Seismic isolation devices 12 Superstructure 14 Substructure 16 Seismic isolation layer 18 Multi-layered rubber bearing 20 Anti-buckling bearing 22, 22A, 22B Laminated rubber 24 Rubber layer 26 Steel plate 28,30 Plate 32 Connecting plate (connecting component) 34 Top 36 sliding part 100 Seismic isolation structures H,P Installation height

Claims

1. A seismic isolation device comprising a multi-stage laminated rubber bearing, which is provided in the seismic isolation layer between the superstructure and the substructure, and consists of laminated rubber arranged in multiple stages in the vertical direction, and a connecting member positioned between the upper and lower laminated rubbers to connect the upper and lower laminated rubbers, The system further includes a buckling prevention support located at a position horizontally separated from the aforementioned multi-stage laminated rubber support, The top of the buckling prevention support is provided with a sliding portion that can be contacted and slid upon by the lower surface of the connecting member when the multi-stage laminated rubber support deforms beyond a predetermined size. A seismic isolation device characterized in that, when the multi-stage laminated rubber bearing deforms beyond a predetermined size, the horizontally displaced connecting member is movably supported in the sliding portion, thereby preventing buckling of the upper and lower laminated rubbers.

2. The seismic isolation device according to claim 1, characterized in that the buckling prevention bearing is arranged in a ring around the multi-stage laminated rubber bearing.

3. A seismic isolation structure characterized by comprising the seismic isolation device described in claim 1 or 2.

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