Seismic isolation device and seismic isolation structure equipped therewith

Abstract

To provide a base isolation device which is not subject to transportation restriction and capable of dealing with large deformation while supporting a superstructure and to provide a base isolation structure provided with the base isolation device.SOLUTION: A base isolation device 10 comprises: a slide bearing 18 which is installed in a base isolation layer 16 between a superstructure 12 and a substructure 14 and supports the superstructure 12; and a laminated rubber bearing 20 which is installed at a distance from the slide bearing 18 in a horizontal direction. The slide bearing 18 has: a slide section 22 which is installed on an upper face of the substructure 14; and a friction section 26 which is installed on a lower face of the superstructure 12 and capable of relatively sliding on a surface of the slide section 22. The slide section 22 is made up of a plurality of chips 22A connected to each other in a direction that the slide section 22 is extended.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, a seismic isolation building having a seismic isolation layer has been known (for example, refer to Patent Document 1). In recent years, the seismic motion to be considered in design has a tendency 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. It is common to manufacture the sliding plate at a factory and transport it to the construction site, and the size of the sliding plate must be 2400 mm or less due to transportation restrictions. For this reason, if the cross-sectional dimension of the column above the bearing is 600 mm, the maximum sliding displacement will be 900 mm, and it is impossible to cope with large deformations exceeding this.

[0004] On the other hand, as conventional seismic isolation devices other than the above, a linear rolling bearing (CLB) and an inclined sliding bearing as shown in Patent Document 2 are known. The inclined sliding bearing of Patent Document 2 can cope with deformations in two horizontal directions orthogonal to each other in a horizontal plane by overlapping rails that slide in one horizontal direction in a cross shape in a plan view.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

[0006] Incidentally, in the case of the inclined sliding bearing described in Patent Document 2 above, if each rail is set to a longer length, it can accommodate large deformations of the seismic isolation layer, thus eliminating transportation limitations. However, this inclined sliding bearing is designed for a maximum vertical support load of less than 100 tf per unit, and does not have enough load-bearing capacity to support a building. Furthermore, commercially available linear rolling bearings can only accommodate deformations up to a maximum of 900 mm, and cannot handle deformations exceeding this. For this reason, there has been a need for a seismic isolation device that is not subject to transportation limitations and can accommodate large deformations while supporting superstructures such as buildings.

[0007] The present invention has been made in view of the above, and aims to provide a seismic isolation device and a seismic isolation structure equipped therewith that are not subject to transportation restrictions and can withstand large deformations while supporting the superstructure. [Means for solving the problem]

[0008] To solve the above-mentioned problems and achieve the objective, the seismic isolation device according to the present invention is provided in a seismic isolation layer between a superstructure and a substructure and comprises a sliding bearing that supports the superstructure and a laminated rubber bearing provided at a position horizontally away from the sliding bearing, wherein the sliding bearing has a sliding portion provided on the upper surface of the substructure and a friction portion provided on the lower surface of the superstructure that can slide relative to the surface of the sliding portion, and the sliding portion is characterized in that it consists of a plurality of chips connected in the direction in which the sliding portion extends.

[0009] Furthermore, another seismic isolation device according to the present invention is characterized in that, in the above-described invention, the sliding portion is constructed by connecting chips with different coefficients of friction.

[0010] Furthermore, another seismic isolation device according to the present invention is characterized in that, in the above-described invention, the region of the sliding portion directly below and around the friction portion is set as a low-friction region with a low coefficient of friction, and the region of the sliding portion on the outer periphery of this low-friction region is set as a high-friction region with a high coefficient of friction.

[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 comprises a sliding bearing provided in a seismic isolation layer between a superstructure and a substructure to support the superstructure, and a laminated rubber bearing provided at a position horizontally separated from the sliding bearing, wherein the sliding bearing has a sliding portion provided on the upper surface of the substructure and a friction portion provided on the lower surface of the superstructure that can slide relative to the surface of the sliding portion, and the sliding portion consists of a plurality of chips joined together in the direction in which the sliding portion extends, thereby having the effect of not being subject to transportation restrictions and being able to accommodate large deformations while supporting the superstructure.

[0013] Furthermore, according to another seismic isolation device of the present invention, the sliding portion is constructed by connecting chips with different coefficients of friction, which has the effect of allowing the coefficient of friction at each chip position of the sliding portion to be set arbitrarily.

[0014] Furthermore, according to another seismic isolation device of the present invention, the region of the sliding portion directly below and around the friction portion is set to a low friction region with a low coefficient of friction, and the region of the sliding portion on the outer periphery of this low friction region is set to a high friction region with a high coefficient of friction, thereby having the effect of suppressing large deformations of the superstructure.

[0015] Furthermore, the seismic isolation structure according to the present invention, since it is equipped with the above-mentioned seismic isolation device, has the effect of providing a seismic isolation structure that can withstand large deformations. [Brief explanation of the drawing]

[0016] [Figure 1] FIG. 1 is a side sectional view showing an embodiment of a seismic isolation device according to the present invention and a seismic isolation structure provided with the same. [Figure 2] FIG. 2 is a photographic view showing a friction material installed on the lower surface of the support portion. [Figure 3] FIG. 3 is a plan view showing an example of joining slip plate chips. [Figure 4] FIG. 4 is a plan sectional view showing an example of arrangement of a low friction region and a high friction region.

Embodiments for Carrying out the Invention

[0017] Hereinafter, embodiments of a seismic isolation device according to the present invention and a seismic isolation structure provided with the same will be described in detail based on the drawings. Note that the present invention is not limited by this embodiment.

[0018] As shown in FIG. 1, a seismic isolation device 10 according to an embodiment of the present invention includes a sliding support 18 provided for a seismic isolation layer 16 between an upper structure 12 and a lower structure 14, and a laminated rubber support 20. The sliding support 18 supports the vertical load of the upper structure 12, and the laminated rubber support 20 bears the rigidity (restoring force) for restoration. A seismic isolation structure 100 according to the present embodiment is a structure including an upper structure 12, a lower structure 14, and the seismic isolation device 10.

[0019] The sliding support 18 supports the upper structure 12, and includes a sliding plate 22 (sliding portion) fixed to the upper surface of the lower structure 14, a support portion 24 which is a columnar rigid body extending downward from the upper structure 12, and a friction material 26 (friction portion) provided on the lower surface of the support portion 24 and relatively slidable on the surface of the sliding plate 22. FIG. 2 shows the friction material 26 attached to the lower surface of the support portion 24. The friction material 26 can be formed of a plate-like object (friction plate) as shown in FIG. 2.

[0020] As shown in FIG. 3, the sliding plate 22 is composed of a plurality of sliding plate chips 22A joined together in the extending direction of the sliding plate 22. The sliding plate chip 22A is, for example, a rectangular small piece with a length and width of about 100 mm, and has a small size and is easy to transport. The sliding plate 22 can be manufactured by joining the sliding plate chips 22A carried into the site at the site. Thereby, the problem that the entire sliding plate 22 becomes too long to be transported can be solved.

[0021] The friction coefficient of the sliding plate chip 22A can be changed by changing the surface treatment or the material for each chip. By joining the sliding plate chips 22A with different friction coefficients, the friction coefficient at each chip position of the sliding part 22 can be arbitrarily set. It is preferable to set an appropriate friction coefficient as the sliding plate 22. Thereby, a sliding bearing 18 with an arbitrary sliding friction coefficient can be realized.

[0022] In the example of FIG. 3, the case where rectangular sliding plate chips 22A of the same size are joined together in the front-back, left-right directions to form a rectangular sliding plate 22 is shown, but the present invention is not limited thereto. The sliding plate chip 22A may have any shape and size as long as a plurality of them can be joined together to form the sliding plate 22, and those with different shapes and sizes may be joined together. Further, the planar shape of the sliding plate 22 may be set to other shapes such as a circle.

[0023] Furthermore, as shown in Figure 4, the sliding plate 22 may be configured with a low-friction region R1 (region with a low coefficient of friction) directly below and around the support portion 24, and a high-friction region R2 (region with a high coefficient of friction) on the outer periphery of the low-friction region R1. This makes it possible to suppress large deformations of the superstructure 12. In this way, if a region with a desired coefficient of friction can be created at a desired position on the sliding plate 22, the degree of design freedom is increased. In the example in Figure 4, a circular sliding plate 22 is shown arranged concentrically with the support portion 24, with a circular low-friction region R1 set on the radially inward side and an annular high-friction region R2 set on the outer periphery side. However, the present invention is not limited to this, and the planar shape of the sliding plate 22 may be other shapes, and the arrangement of each friction region may also be other. In addition, a friction region with a medium coefficient of friction may be provided in stages between the low-friction region R1 and the high-friction region R2.

[0024] The laminated rubber bearing 20 is positioned at a certain horizontal distance from the sliding bearing 18. This laminated rubber bearing 20 is a bearing in which laminated rubber 28 is stacked in two layers, upper and lower. The laminated rubber 28 is cylindrical in shape, with multiple layers of rubber 30 and steel plates 32 stacked in the vertical direction. Plates 34 and 36 are placed on the upper and lower end faces of the laminated rubber 28. The upper end plate 34 of the upper laminated rubber 28A is fixed to the lower surface of the superstructure 12. The lower end plate 36 of the lower laminated rubber 28B is fixed to the upper surface of the substructure 14.

[0025] The plate 36 at the lower end of the upper laminated rubber 28A and the plate 34 at the upper end of the lower laminated rubber 28B are connected via a connecting plate 38. Specifically, the plates 36, the connecting plate 38, and the plate 34 are connected by bolts passed through bolt holes (not shown) and fastening nuts screwed onto the bolts.

[0026] If the laminated rubber 28 is stacked in two layers, there is a concern that it may buckle under vertical load during large deformation. However, since the vertical force from the superstructure 12 is borne by the sliding bearing 18, the height of the laminated rubber bearing 20 does not change even during large deformation, and there is no risk of the laminated rubber 28 buckling.

[0027] According to this embodiment, the sliding bearing 18 bears the vertical load of the superstructure 12, and the laminated rubber bearing 20 bears the restoring force, thereby minimizing the possibility of the laminated rubber 28 buckling during large deformations. Furthermore, by constructing the sliding plate 22 of the sliding bearing 18 with multiple sliding plate chips 22A, there is no need to be limited by size during transportation. Therefore, it is possible to support the superstructure 12 and accommodate large deformations without being limited by transportation constraints.

[0028] Furthermore, the friction coefficient of the sliding plate tip 22A can be set to any desired value by applying various surface treatments or changing the material. This makes it possible to set the area around the support portion 24 as a low-friction region R1 and its outer periphery as a high-friction region R2, thereby realizing a suppression mechanism that corresponds to the amount of deformation.

[0029] In the above embodiment, the example given was that the laminated rubber bearing 20 is a bearing in which laminated rubber 28 is stacked in two layers, upper and lower. However, the laminated rubber bearing of the present invention is not limited to this, and may be a bearing in which laminated rubber is stacked in three or more layers in the vertical direction.

[0030] As described above, the seismic isolation device according to the present invention comprises a sliding bearing provided in the seismic isolation layer between the superstructure and the substructure to support the superstructure, and a laminated rubber bearing provided at a position horizontally separated from the sliding bearing, wherein the sliding bearing has a sliding portion provided on the upper surface of the substructure and a friction portion provided on the lower surface of the superstructure that can slide relative to the surface of the sliding portion, and the sliding portion consists of a plurality of chips joined together in the direction in which the sliding portion extends, so that it is not subject to transportation restrictions and can accommodate large deformations while supporting the superstructure.

[0031] Furthermore, according to another seismic isolation device of the present invention, the sliding portion is constructed by connecting chips with different coefficients of friction, so the coefficient of friction at each chip position of the sliding portion can be arbitrarily set.

[0032] Furthermore, according to another seismic isolation device of the present invention, the region of the sliding portion directly below and around the friction portion is set to a low friction region with a low coefficient of friction, and the region of the sliding portion on the outer periphery of this low friction region is set to a high friction region with a high coefficient of friction, thereby suppressing large deformations of the superstructure.

[0033] Furthermore, since the seismic isolation structure according to the present invention is equipped with the above-mentioned seismic isolation device, it is possible to provide a seismic isolation structure that can withstand large deformations. [Industrial applicability]

[0034] 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 accommodating large deformations while supporting the superstructure without being subject to transportation restrictions. [Explanation of Symbols]

[0035] 10 Seismic isolation devices 12 Superstructure 14 Substructure 16 Seismic isolation layer 18. Sliding bearing 20 Laminated rubber bearings 22. Slide plate (sliding part) 22A Slide Plate Tip (Tip) 24 Bearing part 26 Friction material (friction part) 28, 28A, 28B Laminated rubber 30 Rubber layer 32 Steel plate 34,36 Plates 38 Connecting Plates 100 Seismic isolation structures R1 Low friction area R2 High friction area

Claims

1. A seismic isolation device comprising a sliding bearing provided in the seismic isolation layer between the superstructure and the substructure to support the superstructure, and a laminated rubber bearing provided at a position horizontally separated from the sliding bearing, The seismic isolation device is characterized in that the sliding bearing has a sliding portion provided on the upper surface of the lower structure and a friction portion provided on the lower surface of the upper structure that is capable of sliding relative to the surface of the sliding portion, the sliding portion consists of a plurality of rectangular chips joined together in the direction in which the sliding portion extends, and the plurality of chips are configured to be joined together on site.

2. The seismic isolation device according to claim 1, characterized in that the sliding portion is formed by connecting chips with different coefficients of friction.

3. The seismic isolation device according to claim 1 or 2, characterized in that the sliding portion consists of a plurality of rectangular chips of the same size joined together in the direction in which the sliding portion extends.

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

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