Hardening type seismic isolation device and seismic isolation structure equipped therewith

Abstract

To provide a hardening seismic isolation device that is effective in two horizontal directions and to provide a seismic isolation structure comprising the same.SOLUTION: A hardening seismic isolation device comprises: a rolling support 18 having a guide 28 movable along an upper guide rail 24 and a lower guide rail 26, and supporting an upper structure 12A; and a hardening device 20 having a characteristic that a rigidity changes according to horizontal displacement, and suppressing displacement in a horizontal direction, and a rotational inertia device 22 suppressing vibration in a horizontal direction by utilizing rotational inertia force, that are provided to connect between the upper structure 12A and the guide 28, and between a lower structure 14A and the guide 28, respectively. The hardening device 20 and the rotational inertia device 22 are disposed so as to respectively suppress displacement or vibration in two horizontal directions crossing each other.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] Conventionally, a seismic isolation structure is known as a method of protecting a building from an earthquake by introducing a low-rigidity layer into the foundation part of the building to extend the natural period of the building and thereby reducing the acceleration at the time of earthquake input. However, on the other hand, when a long-period earthquake occurs, there is a concern that the displacement of the seismic isolation layer becomes excessive, and also during the Kumamoto earthquake in 2016, many seismic isolation buildings were damaged due to the occurrence of long-period pulses. In order to solve such problems, a hardening type seismic isolation structure as shown in Non-Patent Document 1 has been developed. This hardening type seismic isolation structure includes a hardening type device that acts in a single direction, and prevents excessive displacement by increasing the rigidity of the seismic isolation layer as the displacement increases. This structure is realized by fixing a wire to the mass to be controlled. The rigidity of the hardening type device can be adjusted by changing the rigidity of the disc spring.

[0003] On the other hand, as prior art related to the above, for example, those described in Patent Documents 1 to 3 are known. The structures described in Patent Documents 1 and 2 are structures using an inertial mass damper, a vibration isolation structure, etc. By rotating a weight, it brings the same effect as when a large mass is added, and suppresses the vibration of the building. Patent Document 3 is a cruciform seismic isolation structure using a rolling bearing, which exhibits effectiveness in two horizontal directions.

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

[0005] [Patent Document 1] Japanese Patent Publication No. 2012-189104 [Patent Document 2] Japanese Patent Publication No. 2020-186744 [Patent Document 3] Japanese Patent Application Publication No. 10-280730 [Overview of the project] [Problems that the invention aims to solve]

[0006] Incidentally, seismic forces are applied to actual buildings from any horizontal direction. However, the conventional hardened seismic isolation structure described above is only effective in one horizontal direction, making it difficult to apply to actual buildings in its original form. Therefore, there was a need to develop a technology that could be effective in two horizontal directions to cope with seismic forces in any horizontal direction.

[0007] The present invention has been made in view of the above, and aims to provide a hardening type seismic isolation device that can exert its effect in two horizontal directions and a seismic isolation structure equipped therewith. [Means for solving the problem]

[0008] To solve the above-mentioned problems and achieve the objective, the hardened seismic isolation device according to the present invention is provided in a seismic isolation layer between a superstructure and a substructure, and is a hardened seismic isolation device capable of relative horizontal displacement between the superstructure and the substructure, comprising: an upper guide rail arranged in one horizontal direction in the superstructure; a lower guide rail arranged in one horizontal direction intersecting the extension direction of the upper guide rail in the substructure; a rolling bearing that supports the superstructure and has a guide that is movable along the upper guide rail and the lower guide rail; a hardened device provided to connect the superstructure and the guide, and the substructure and the guide, respectively, and having the characteristic of changing rigidity according to horizontal displacement and suppressing horizontal displacement; and a rotational inertia device that suppresses horizontal vibration using rotational inertia force, wherein the hardened device and the rotational inertia device are arranged to suppress displacement or vibration in two intersecting horizontal directions, respectively.

[0009] Furthermore, another hardening-type seismic isolation device according to the present invention is characterized in that, in the above-described invention, the hardening-type device has one or more wires and a restoring spring mechanism provided on the end side of the wires.

[0010] Furthermore, another hardening-type seismic isolation device according to the present invention is characterized in that, in the above-described invention, the wires of the hardening-type device are arranged diagonally with respect to the height direction and the direction of extension of the upper guide rail or the lower guide rail.

[0011] Furthermore, another hardening-type seismic isolation device according to the present invention is characterized in that the superstructure is a column, beam, or floor in the invention described above.

[0012] Furthermore, the seismic isolation structure according to the present invention is characterized by being equipped with the hardening type seismic isolation device described above. [Effects of the Invention]

[0013] The hardened seismic isolation device according to the present invention is provided in a seismic isolation layer between a superstructure and a substructure, and is capable of relative horizontal displacement between the superstructure and the substructure. The hardened seismic isolation device includes an upper guide rail arranged in one horizontal direction in the superstructure, a lower guide rail arranged in one horizontal direction intersecting the direction of extension of the upper guide rail in the substructure, and a rolling bearing that supports the superstructure and has a guide that is movable along the upper guide rail and the lower guide rail, a hardened device provided to connect the superstructure and the guide, and the substructure and the guide, respectively, and having the characteristic of changing rigidity according to horizontal displacement and suppressing horizontal displacement, and a rotational inertia device that suppresses horizontal vibration using rotational inertia force. The hardened device and the rotational inertia device are arranged to suppress displacement or vibration in two intersecting horizontal directions, respectively, thus providing the effect of being effective in two horizontal directions.

[0014] Furthermore, according to other hardening-type seismic isolation devices of the present invention, the hardening device has one or more wires and a restoring spring mechanism provided on the end side of these wires, so the rigidity of the hardening device and the magnitude of the restoring force can be easily adjusted by changing the rigidity of the restoring spring mechanism.

[0015] Furthermore, according to another hardening-type seismic isolation device of the present invention, the wires of the hardening device are arranged diagonally with respect to the height direction and the direction of extension of the upper guide rail or the lower guide rail, so that the magnitude of the restoring force by the hardening device can be adjusted by changing the arrangement direction of the wires.

[0016] Furthermore, according to other hardening-type seismic isolation devices of the present invention, since the superstructure is a column, beam, or floor, it is possible to realize a hardening-type seismic isolation device that exerts its effect in two horizontal directions below the column, beam, or floor.

[0017] Further, according to the aseismic structure of the present invention, since the above-described cured type seismic isolation device is provided, there is an effect that an aseismic structure capable of exerting effectiveness in two horizontal directions can be provided.

Brief Description of Drawings

[0018] [Figure 1] FIG. 1 is a schematic side view showing an embodiment of a cured type seismic isolation device according to the present invention and an aseismic structure provided with the same. [Figure 2] FIG. 2 is a view showing this embodiment, (1) is a side view, and (2) is a plan view. [Figure 3] FIG. 3 is an explanatory view of a modification of this embodiment, (1) is Modification 1, (2) is Modification 2, (3) is Modification 3, and (4) is Modification 4. [Figure 4] FIG. 4 is an explanatory view for verifying the effect of the present invention. [Figure 5] FIG. 5 is a view showing the verification result of the effect of the present invention.

Embodiments for Carrying Out the Invention

[0019] Hereinafter, embodiments of a cured type seismic isolation device according to the present invention and an aseismic 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. [[ID=*30]]

[0020] As shown in FIG. 1, a cured type seismic isolation device 10 according to an embodiment of the present invention is provided in a seismic isolation layer 16 between an upper structure 12 and a lower structure 14, and is a device that enables relative displacement between the upper structure 12 and the lower structure 14 in the horizontal direction. The aseismic structure according to this embodiment is a structure including this cured type seismic isolation device 10, the upper structure 12, and the lower structure 14.

[0021] As shown in Figure 2, the hardened seismic isolation device 10 is a seismic isolation structure consisting of rolling bearings 18, with a seismic isolation layer equipped with a hardened device 20 and a rotational inertia device 22 stacked on top of it. The hardened device 20 and the rotational inertia device 22 are positioned to suppress displacement or vibration in two horizontal directions, front, back, left, and right, which intersect with each other. In this embodiment, the hardened device 20 and the rotational inertia device 22 are used in combination with the rolling bearings 18 acting in two horizontal directions to exert the forces of the hardened device 20 and the rotational inertia device 22.

[0022] Normally, rolling bearings are placed under columns, but since the purpose of the hardening device 20 is to exhibit nonlinear rigidity, it is expected that a similar effect can be obtained by placing it under beams or the like in combination with the rolling bearing 18. In this embodiment, the rolling bearing 18 is placed between the mounting member 12A located on the lower surface of the superstructure 12 and the mounting member 14A located on the upper surface of the substructure 14. The mounting member 12A is assumed to be a column, beam, floor, etc., and the mounting member 14A is assumed to be a foundation, floor, etc.

[0023] As shown in Figure 2, the rolling support 18 has an upper guide rail 24 positioned in the left-right direction (one horizontal direction) on the lower surface of the mounting member 12A, a lower guide rail 26 positioned in the front-rear direction (one horizontal direction) intersecting the extension direction of the upper guide rail 24 on the upper surface of the mounting member 14A, and a block-shaped guide 28 that fits onto the upper guide rail 24 and the lower guide rail 26 and is movable along each guide rail 24, 26, and supports the load of the superstructure 12 via the guide 28. In this way, the guide rails 24 and 26, which can guide the guide 28 in one horizontal direction, are arranged on the upper and lower sides, and are arranged so that the guiding directions are perpendicular to each other. The guide 28 has a ball bearing mechanism (not shown) at the contact portion with the guide rails 24, 26. Each guide rail 24, 26 has a certain length, and when viewed from above, the intersecting portion has a cross shape.

[0024] The hardening device 20 is a device that has the characteristic of changing its rigidity in accordance with horizontal displacement and suppresses horizontal displacement, and is composed of a wire 30 and a plurality of disc springs 32 (restoring spring mechanism) connected to the end of the wire 30. Although the natural period of a building differs in the short side direction and the long side direction of the planar cross-section, the rigidity of the hardening device 20 and the magnitude of the restoring force can be easily adjusted by changing the rigidity of the disc springs 32. This makes it possible to adjust the rigidity of the hardening device 20 to suit each direction of the building. The hardening devices 20 are arranged on the upper and lower sides. Note that in Figure 2(2), the hardening device 20 arranged on the upper side is omitted from the illustration for convenience.

[0025] Two sets of the upper curing devices 20 are provided symmetrically to each other on the side (right side) of the guide 28. The wire 30 of the curing device 20 is stretched horizontally in the front-to-back direction. One end of the wire 30 is connected to a fixing member 28A on one side (right side) of the guide 28, and the other end is connected to a disc spring 32 located on the outside of a fixing member 34, which is fixed to an attachment member 12A located at a distance from the guide 28, through a hole in the fixing member 34.

[0026] Two sets of the lower curing devices 20 are provided symmetrically on the sides (front) of the guide 28. The wire 30 of the curing device 20 is stretched horizontally in the left-right direction. One end of the wire 30 is connected to a fixing member 28A on one (front) side of the guide 28, and the other end is connected to a disc spring 32 located on the outside of the fixing member 34, through a hole in the fixing member 34 which is fixed to an attachment member 14A located to the left and right of the guide 28.

[0027] In the example shown in the figure, only one wire 30 is used, but the present invention is not limited to this, and multiple wires 30 may be used, as will be explained in the modified examples below. This makes it possible to increase the restoring force exerted by the curing device 20. Furthermore, when attaching the wire 30 to the guide 28, it is also possible to attach it diagonally to the vertical, horizontal, or front-to-back directions, as will be explained in the modified examples below. By changing the arrangement direction of the wire 30, it is possible to adjust the magnitude of the restoring force exerted by the curing device 20.

[0028] The rotational inertia device 22 suppresses horizontal vibrations by utilizing rotational inertia force and consists of a ball screw 36 and a rotational inertia mechanism 38 equipped with a wheel engaged with the end of the ball screw 36. The rotational inertia mechanism 38 is a well-known rotational inertia damper that converts the linear motion of the ball screw 36 into the rotational motion of the wheel and exerts an inertial mass effect. One set of rotational inertia devices 22 is arranged on the upper and lower sides. Note that the rotational inertia device 22 is not limited to a type in which the wheel rotates, and other types of rotational inertia dampers may be used. It is expected that similar effects can be obtained even in this case.

[0029] The upper rotational inertia device 22 is located to the side (left) of the guide 28. The ball screw 36 of this rotational inertia device 22 extends horizontally in the left-right direction. One end of the ball screw 36 is connected to the left side of the guide 28, and the other end is connected to a rotational inertia mechanism 38 fixed to a mounting member 12A located to the left of the guide 28. The lower rotational inertia device 22 is located to the side (rear) of the guide 28. The ball screw 36 of this rotational inertia device 22 extends horizontally in the front-rear direction. One end of the ball screw 36 is connected to the rear side of the guide 28, and the other end is connected to a rotational inertia mechanism 38 fixed to a mounting member 12A located to the rear of the guide 28.

[0030] According to the hardened seismic isolation device 10 of this embodiment, by arranging two seismic isolation layers, one above the other, with the hardened device 20 and the other with the rotational inertia device 22, in a vertically stacked configuration for a seismic isolation structure using rolling bearings 18, the device can exert its effect in two horizontal directions: left-right and front-back. This makes it possible to apply the device to actual seismic isolation building structures and reduces response displacement and acceleration for earthquakes in any direction. Therefore, even when long-period earthquakes occur, it becomes possible to realize a seismic isolation layer that exerts its effect not only in one horizontal direction but also in two horizontal directions in terms of displacement and acceleration.

[0031] (modified version) The above embodiments show the basic mounting patterns of the present invention, but the present invention is not limited thereto. For example, a configuration in which the hardening device 20 is arranged diagonally with respect to the left-right direction, as shown in Figure 3(1), a configuration in which it is arranged diagonally with respect to the left-right direction and in pairs front-to-back, as shown in Figure 3(2), a configuration in which multiple wires 30 are used (two in the example shown), as shown in Figure 3(3), or a configuration in which the hardening device 20 is arranged diagonally in the height direction, as shown in Figure 3(4) may be adopted. By changing the arrangement of the hardening device 20 in this way, it is expected that it will be effective in adjusting the restoring force by the hardening device 20 and will also help prevent the seismic isolation structure from floating up.

[0032] (Verification of the effects of the present invention) Next, we will explain the verification of the effects of the present invention. In this verification, we will examine two cases for a base-isolated structure with a natural period of 3.3 seconds and a damping constant of 10%: (1) a comparative example (a normal base-isolated structure without a hardened base-isolation device) and (2) an embodiment of the present invention (with a hardened base-isolation device). In particular, this verification is performed using response analysis with seismic waves observed in Nishihara Village during the 2016 Kumamoto earthquake, which caused significant damage to base-isolated structures. The time waveforms of the seismic waves used in the analysis are shown in Figures 4(1) and (2). Figure 4(1) shows the east-west component, and (2) shows the north-south component.

[0033] Figures 4(3) to 4(6) and 45 show the response analysis results. Figure 4(3) shows the response displacement in the east-west direction, (4) shows the response displacement in the north-south direction, (5) shows the response acceleration in the east-west direction, and (6) shows the response acceleration in the north-south direction. Figure 5(1) shows the displacement orbit, and (2) shows the acceleration orbit.

[0034] The response analysis results above clearly show that by using the hardened seismic isolation device of the present invention (Example), response displacement and acceleration can be reduced in two horizontal directions: east-west and north-south. Nishihara waves are called long-period pulses, and when input to building structures with long natural periods, such as seismic isolation structures, the response displacement becomes excessive, raising concerns about collision with retaining walls. The response analysis results above also clearly showed that when the hardened seismic isolation device is not installed (Comparative Example), the response displacement exceeds 1m, especially in the east-west direction. It should be noted that the clearance of a typical building is at most about 0.75m.

[0035] On the other hand, when the hardened seismic isolation device is installed (Example), it can be seen that not only is the maximum response displacement reduced, but the maximum response acceleration is also suppressed to the same level as when the hardened seismic isolation device is not installed (Comparative Example). Since acceleration and displacement usually have a trade-off relationship, it is very difficult to reduce both, but it has been shown that by using the hardened seismic isolation device of the present invention, it is possible to reduce the response displacement without increasing the maximum acceleration response in the east-west and north-south directions.

[0036] As described above, the hardened seismic isolation device according to the present invention is a hardened seismic isolation device provided in a seismic isolation layer between a superstructure and a substructure, which is capable of relative horizontal displacement between the superstructure and the substructure, and comprises an upper guide rail arranged in one horizontal direction in the superstructure, a lower guide rail arranged in one horizontal direction intersecting the direction of extension of the upper guide rail in the substructure, a rolling bearing that supports the superstructure and has a guide that is movable along the upper guide rail and the lower guide rail, a hardened device provided to connect the superstructure and the guide, and the substructure and the guide, respectively, which has the characteristic of changing rigidity according to horizontal displacement and suppresses horizontal displacement, and a rotational inertia device that suppresses horizontal vibration using rotational inertia force, and the hardened device and the rotational inertia device are arranged to suppress displacement or vibration in two intersecting horizontal directions, respectively, so that they can exert their effect in two horizontal directions.

[0037] Furthermore, according to another hardening-type seismic isolation device of the present invention, the hardening device has one or more wires and a restoring spring mechanism provided on the end side of these wires, so the rigidity and magnitude of the restoring force of the hardening device can be easily adjusted by changing the rigidity of the restoring spring mechanism.

[0038] Furthermore, according to another hardening-type seismic isolation device of the present invention, the wires of the hardening device are arranged diagonally with respect to the height direction and the direction of extension of the upper guide rail or the lower guide rail, so the magnitude of the restoring force by the hardening device can be adjusted by changing the arrangement direction of the wires.

[0039] Furthermore, according to another hardening-type seismic isolation device of the present invention, since the superstructure is a column, beam, or floor, it is possible to realize a hardening-type seismic isolation device that exerts its effect in two horizontal directions below the column, beam, or floor.

[0040] Furthermore, the seismic isolation structure according to the present invention is equipped with the hardening type seismic isolation device described above, and therefore can provide a seismic isolation structure that can exert its effect in two horizontal directions. [Industrial applicability]

[0041] As described above, the hardening type seismic isolation device and the seismic isolation structure equipped therewith are useful for seismic isolation structures installed in buildings and the like, and are particularly suitable for exerting seismic isolation effects in two horizontal directions. [Explanation of symbols]

[0042] 10. Hardening type seismic isolation device 12 Superstructure 12A, 14A mounting components 14 Substructure 16 Seismic isolation layer 18 Rolling bearing 20 Curing equipment 22 Rotational Inertia Device 24 Upper guide rail 26 Lower guide rail 28 Guide 28A Fixing member 30 wires 32. Disc spring (return spring mechanism) 34 Fixing member 36 Ball Screw 38. Rotational Inertia Mechanism

Claims

1. A hardened seismic isolation device provided in the seismic isolation layer between the superstructure and the substructure, which is capable of relative horizontal displacement between the superstructure and the substructure, The superstructure includes an upper guide rail arranged in one horizontal direction, the lower structure includes a lower guide rail arranged in one horizontal direction intersecting the direction of extension of the upper guide rail, and a rolling support that supports the superstructure and has a guide that is movable along the upper guide rail and the lower guide rail. The system includes a hardening device that connects the superstructure and the guide, and the lower structure and the guide, respectively, and has the characteristic of changing rigidity according to horizontal displacement and suppressing horizontal displacement, and a rotational inertia device that suppresses horizontal vibration using rotational inertia force, The hardening apparatus and the rotational inertia apparatus are arranged to suppress displacement or vibration in two intersecting horizontal directions, respectively. The hardening device, which is provided to connect the superstructure and the guide, has one or more wires connected to the guide, and a restoring spring mechanism provided on the end of the wires and positioned outside a fixing member fixed to the superstructure at a position away from the guide. The hardening device, which is provided to connect the substructure and the guide, has one or more wires connected to the guide, and a restoring spring mechanism provided on the end of the wires and positioned outside a fixing member fixed to the substructure at a position away from the guide. The hardening type seismic isolation device is characterized in that the wire is arranged diagonally in the height direction and in the direction of extension of the upper guide rail or the lower guide rail.

2. The hardening type seismic isolation device according to Claim 1, characterized in that the superstructure is a column, beam or floor.

3. A seismic isolation structure characterized by comprising a hardening type seismic isolation device as described in claim 1 or 2.

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