Displacement suppression device and seismic isolation structure equipped with the same

Abstract

To provide a hardening type device capable of effectively suppressing horizontal response displacement of a seismic isolation building using tension members and a seismic isolation structure equipped with this.SOLUTION: There provided is a hardening type device 10 used to control displacement of a superstructure 16 which is provided between a superstructure 16 provided over a foundation 12 via seismic isolation members 24 and a structure body 20 arranged opposite to at least a portion of a side wall 18 of the superstructure 16 with a gap a, which comprises tension members 22 connecting the side wall 18 of the superstructure 16 and the structure body 20, and the tension members 22 are arranged at an inclination state from the vertical direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a device for a displacement control type seismic isolation structure Displacement suppression and a seismic isolation structure equipped with the same. (Hereinafter, referred to as the hardening device.)

Background Art

[0002] Conventionally, seismic isolation buildings are known as a structural form that reduces seismic input by extending the period of the building using seismic isolation devices such as laminated rubber. Since the response acceleration can be greatly reduced, it is also effective in suppressing the overturning of furniture during an earthquake.

[0003] However, in recent years, large seismic waveforms have often been observed, and there is a concern that the displacement of seismic isolation buildings may become larger than the design assumed value and collide with the retaining wall. Furthermore, recently, countermeasures against long-period and long-duration ground motions have also been required, and it has become important not only to extend the period but also to further suppress the displacement.

[0004] Focusing on displacement suppression, it is effective to set a large number of dampers to increase attenuation or to provide a stopper to avoid collision with the retaining wall. However, these measures lead to a shortening of the building's short period, which is contrary to the reduction of response acceleration due to the lengthening of the period of the seismic isolation structure. For these reasons, a structure that suppresses the response displacement without impairing the response acceleration reduction effect is required.

[0005] As a conventional seismic isolation structure that suppresses the response displacement without impairing the response acceleration reduction effect, for example, a structural form combining a hardening type device, a rotational inertia device, and a variable damper device is known (see, for example, Patent Documents 1 to 5).

[0006] On the one hand, a vibration damping device using a tension member such as a rope material is known (see, for example, Patent Document 6). In a simple spring system in which the rope material is arranged in a direction orthogonal to the vibration direction, when the equation of motion is derived considering geometric non-linearity and approximated by Taylor expansion, a third-order term appears (see, for example, Non-Patent Document 1), and a hardening-type restoring force characteristic can be realized. Further, if the rope material is initially given slack, no force is generated until the slack disappears, resulting in a restoring force characteristic with a gap.

[0007] Arranging the rope material in a direction orthogonal to the vibration direction and realizing the hardening-type characteristic by geometric non-linearity is a common method adopted in many experiments both overseas and domestic in research related to non-linearity (see, for example, Non-Patent Document 2).

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Non-Patent Documents

[0009]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0010] By the way, in a curing device with a tension member such as a rope member arranged horizontally, the function is exerted only in a specific one vibration direction. However, in an actual seismic isolation building, since the upper building moves in an arbitrary horizontal direction, there is a problem with this arrangement as it is. Therefore, a device that can cope with any horizontal direction is required.

[0011] The clearance of the seismic isolation layer of a seismic isolation building is generally on the order of 50 cm to 80 cm, and the curing device requires a mechanism such that the rope member remains in the elastic range and does not break even when a large horizontal displacement occurs. As a method for that, it is effective to increase the length of the rope member (separate the fixing positions of the ropes as much as possible) to reduce the elongation of the rope member with respect to the horizontal displacement. However, stretching a long rope member in the horizontal direction of the seismic isolation layer may interfere with the layout plan and daily maintenance work.

[0012] Furthermore, since it is necessary to generate a large load that also affects the vibration characteristics of the building, a member with sufficient rigidity is required.

[0013] In the case of a high-rise base-isolated building, an additional axial force may be generated in the base isolation device due to the influence of the building's overturning moment, which may lead to damage to the base isolation device. As the additional axial force, a compressive force is generated in the base isolation device on the side where the clearance between the building and the retaining wall becomes narrow, and a pulling force is generated in the base isolation device on the side where the clearance becomes wide. Therefore, it is also necessary to devise a means to relieve the additional axial force generated by the overturning moment.

[0014] The present invention has been made in view of the above, and an object thereof is to provide a hardening type device that can effectively suppress the horizontal response displacement of a base-isolated building using a tension member, and a base-isolated structure provided with the same.

Means for Solving the Problems

[0015] In order to solve the above-described problems and achieve the object, a hardening type device according to the present invention is provided between an upper structure provided via a base isolation member on a base portion and a structure disposed to face at least a part of a side wall of the upper structure with a gap therebetween, and is a hardening type device used to suppress displacement of the upper structure, and includes a tension member that connects the side wall of the upper structure and the structure, and the tension member is disposed in a state inclined from the vertical direction.

[0016] Moreover, another hardening type device according to the present invention is the above-described invention, wherein the tension member is disposed with the structure side upward and the upper structure side downward in the vertical direction, and with the upper structure side closer to the lower surface corner of the upper structure and the structure side farther from the lower surface corner of the upper structure in the horizontal direction.

[0017] Moreover, another hardening type device according to the present invention is the above-described invention, wherein the vertical height of the tension member is 6 times or more the gap between the side wall of the upper structure and the structure, and the horizontal length of the tension member is 2 times or more the gap between the side wall of the upper structure and the structure.

[0018] Further, another curing type device according to the present invention is characterized in that, in the above-described invention, it further includes a resonance avoidance member for avoiding the resonance of the tension member.

[0019] Further, a seismic isolation structure according to the present invention is characterized by including the above-described curing type device.

Advantages of the Invention

[0020] According to the curing type device of the present invention, it is provided between an upper structure provided via a seismic isolation member on a base portion and a structure disposed to face at least a part of a side wall of the upper structure with a gap therebetween, and is a curing type device used for suppressing the displacement of the upper structure. It includes a tension member connecting the side wall of the upper structure and the structure, and this tension member is disposed in an inclined state from the vertical direction. Therefore, it has the effect that the horizontal response displacement of the upper structure (seismic isolation building) can be effectively suppressed using the tension member.

[0021] Further, according to another curing type device of the present invention, the tension member is disposed with the structure side upward and the upper structure side downward in the vertical direction, and in the horizontal direction, the upper structure side is closer to the lower surface corner portion of the upper structure and the structure side is farther from the lower surface corner portion of the upper structure. Therefore, when the upper structure is displaced in an arbitrary horizontal direction, tension is generated only in the tension member on the side where the gap becomes smaller. For this reason, it has the effect that the axial force applied to the compression side laminated rubber due to the overturning moment can be reduced.

[0022] Further, according to another curing type device of the present invention, the vertical height of the tension member is 6 times or more the gap between the side wall of the upper structure and the structure, and the horizontal length of the tension member is 2 times or more the gap between the side wall of the upper structure and the structure. Therefore, when the upper structure is displaced in an arbitrary horizontal direction, tension is generated only in the tension member on the side where the gap becomes smaller. For this reason, it has the effect that the axial force applied to the compression side laminated rubber due to the overturning moment can be reduced.

[0023] Further, according to another curing device of the present invention, since it further includes a resonance avoidance member for avoiding the resonance of the tension member, it has the effect of being able to avoid the resonance of the tension member.

[0024] Further, according to the seismic isolation structure of the present invention, since it includes the above-described curing device, it has the effect of being able to provide a seismic isolation structure capable of suppressing the horizontal response displacement of the superstructure.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0026] Hereinafter, embodiments of a curing device according to the present invention and a seismic isolation structure including the same will be described in detail with reference to the drawings. Note that the present invention is not limited by this embodiment.

[0027] As shown in FIG. 1, a hardening type device 10 according to an embodiment of the present invention is provided between an upper structure 16 provided via a seismic isolation layer 14 underground above a base portion 12 and a retaining wall 20 (structure) disposed to face the side wall 18 of the upper structure 16 with a seismic isolation layer clearance a (gap) therebetween, and is used to suppress displacement of the upper structure 16. The hardening type device 10 includes a rope member 22 (22a, 22b: tension member) that connects the side wall 18 of the upper structure 16 and the retaining wall 20.

[0028] A laminated rubber 24 (seismic isolation member) is disposed in the seismic isolation layer 14. The upper structure 16 is a building having a square horizontal cross section, and the retaining wall 20 is a wall body installed above the base portion 12 and is installed in a square shape so as to surround the entire periphery of the upper structure 16. A seismic isolation structure 100 according to an embodiment of the present invention includes the above-described base portion 12, seismic isolation layer 14, upper structure 16, retaining wall 20, and hardening type device 10. Note that the upper structure is not limited to a square shape and may have a rectangular cross section or the like.

[0029] The rope member 22 (22a, 22b) is disposed in the space of the seismic isolation layer clearance a in a state inclined from the vertical direction. More specifically, the rope member 22 is disposed so as to be connected in a manner such that the retaining wall 20 side is upward and the upper structure 16 side is downward in the vertical direction. Also, the rope member 22 is disposed such that the upper structure 16 side is closer to the four corners (lower surface corner portions) of the lower surface of the upper structure 16 and the retaining wall 20 side is farther from the four corners of the lower surface of the upper structure 16 in the horizontal plane. The vertical height b of the rope member 22 is preferably set to a length sufficiently larger than the seismic isolation layer clearance a, and for example, it is desirable to set it to 6 times or more the seismic isolation layer clearance a. Also, the horizontal length c of the rope member 22 is preferably set to a value smaller than the height b of the rope member 22 and 2 times or more the seismic isolation layer clearance a between the side wall 18 of the upper structure 16 and the retaining wall 20.

[0030] Next, the operation and effect of the rope member 22 (22a, 22b) arranged as described above will be described. As shown in Fig. 1(2), when the X and Y directions are set in the horizontal plane, and the seismic isolation layer clearance is a, the height of the rope material 22 is b, and the horizontal length of the rope material 22 is c, the length of the rope material 22 when there is no slack is L0 = (a×a + b×b + c×c). 0.5 It becomes like this.

[0031] First, consider the case where the superstructure 16 moves by x = a in the X direction, that is, the rope material 22 at the time of collision with the retaining wall. Fig. 2(1) shows the situation after the movement. However, only the lower half of the rope material is shown because of X-axis symmetry.

[0032] The rope materials 1 and 2 in Fig. 2(1) will be described with attention. Note that since the rope material 3 is in the direction in which the material contracts, no force is generated. The length of the rope material 1 is L1x = (a×a + b×b + (c + a)×(c + a)). 0.5 The length of the rope material 2 is L2x = ((a + a)×(a + a) + b×b + c×c). 0.5 Here, if c > 2×a is set, then L1x > L2x.

[0033] If the rope material has slack and the natural length of the rope is L = L2x = ((a + a)×(a + a) + b×b + c×c). 0.5 Then, the rope material 2 will also not bear the tension. Therefore, by using a rope material with slack, only the rope material 1 can generate tension.

[0034] Next, consider the case where the superstructure 16 moves by x = a in the X direction and y = a in the Y direction. Fig. 2(2) shows the situation after the movement. However, only the lower right side of the rope material is shown because of 45-degree axis symmetry.

[0035] The rope materials 1, 2, and 4 in Fig. 2(2) will be described with attention. Note that since the rope material 3 is in the direction in which the material contracts, no force is generated. The length of the rope material 1 is L1xy = ((a + a)×(a + a) + b×b + (c + a)×(c + a)). 0.5 The length of the rope member 2 is L2xy = ((a + a)×(a + a) + b×b + (c - a)×(c - a)) 0.5 The length of the rope member 4 is L3xy = ((a + a)×(a + a) + b×b + (c + a)×(c + a)) 0.5

[0036] Let the natural length of the rope with sag be L = ((a + a)×(a + a) + b×b + c×c) 0.5 be such that. Here, if c > 2×a is set, then L > L2xy, and no tension is generated in the rope member 2. Also, L < L3xy, and tension is generated in the rope member 4.

[0037] As described above, among the arranged rope members 22, when the superstructure 16 moves in an arbitrary horizontal direction, tension is generated only in the rope member 22 on the side where the seismic isolation layer clearance a becomes smaller.

[0038] Therefore, according to the present embodiment, by arranging the rope member 22 in a substantially vertical direction, the response displacement of the superstructure 16 in an arbitrary horizontal direction can be effectively suppressed using the rope member 22. Also, by using the rope member 22 that can be manufactured at low cost, a hardening-type restoring force characteristic due to geometric nonlinearity can be realized.

[0039] Also, as shown in FIG. 3(1), since the tension acts in the direction of pulling up the superstructure 16, there is also an effect of reducing the axial force applied to the laminated rubber 24 on the compression side due to the overturning moment.

[0040] The arrangement of the rope member 22 is also effective for the torsion of the seismic isolation layer 14. As shown in FIG. 3(2), when the superstructure 16 is displaced counterclockwise, tensile force is generated in the rope member 22 indicated by the arrow, and it functions in the direction of correcting the torsion.

[0041] Incidentally, since the rope material 22 is long, it may resonate during an earthquake. Therefore, as shown in FIG. 4, a support member 26 (resonance avoidance member) for avoiding resonance of the rope material 22 may be further provided. The support member 26 is installed from near the center of the rope material 22 to the retaining wall 20. As the material of the support member 26, for example, a stretchable material such as a rubber material can be used. When only one support member 26 is used, there is a possibility of resonance in a direction orthogonal to the plane formed by the rope material 22 and the support member 26. Therefore, it is desirable to use two or more support members 26 and arrange them so that all the members (rope material 22, support member 26) are not on the same plane. Furthermore, by providing a damping function to the support member 26, resonance can be actively avoided, and vibration reduction can be achieved by energy absorption.

[0042] In the above embodiment, the case where the rope material 22 is arranged in the space of the seismic isolation layer clearance a of the underground seismic isolation layer 14 has been described as an example. However, the present invention is not limited to this, and the rope material 22 may be arranged anywhere as long as there is sufficient space in the vertical direction. For example, as shown in FIG. 5(1), in a void-type superstructure 16 in which a structure 28 is arranged at the center, the rope material 22 can be arranged in the space between the structure 28 and the superstructure 16. Further, as shown in FIG. 5(2), a column 30 may be provided outside the superstructure 16, and the rope material 22 may be arranged between the column 30 and the superstructure 16.

[0043] (Example) Next, an example of the present invention will be described. This example was applied with the following specifications. Seismic isolation layer clearance a = 0.75 m Height b of the rope material = 6 m (= 8 × a) Horizontal length c of the rope material = 3 m (= 4 × a)

[0044] Length L0 of the rope material when there is no sag = (a × a + b × b + c × c) 0.5 = 6.750 m When the superstructure moves by x = a in the X direction, Lx = (a × a + b × b + (c + a) × (c + a))0.5 =7.115 m When the superstructure moves by y = a in the Y direction, Ly = ((a + a)×(a + a)+b×b + c×c) 0.5 =6.874 m When the superstructure moves by x = a and y = a, Lxy = ((a + a)×(a + a)+b×b+(c + a)×(c + a)) 0.5 =7.233 m Assuming that the length of the rope material with sag is L = Ly = 6.874 m, the strain when the superstructure moves by x = a and y = a is 7.233 / 6.874 = 1.052 (strain = 5.2%)

[0045] Here, in the case of a normal wire rope, it is difficult to apply it as a rope material because it breaks at a strain of about 5%. As the rope material used in this embodiment, for example, a synthetic fiber rope used for mooring ropes in the marine and ship fields is useful. Synthetic fiber ropes are available in a variety of products with an elongation at break of about 4% to 30%, and are lightweight and can be used even under harsh conditions compared to iron wire rope materials. Due to their lightweight, the work during installation and maintenance becomes easier.

[0046] Considering the safety factor, even when using a synthetic fiber rope, it is desirable to keep the strain within about 5%. Increasing the height b of the rope material can reduce the strain, but as described above, it is desirable that the height b of the rope material is 6 times or more the seismic isolation layer clearance a.

[0047] According to this embodiment, it is possible to effectively suppress any horizontal response displacement of the superstructure.

[0048] As described above, according to the hardening type device of the present invention, between an upper structure provided via a seismic isolation member on a base portion and a structure disposed to face at least a part of a side wall of the upper structure with a gap therebetween, which is a hardening type device used to suppress displacement of the upper structure, and includes a tension member connecting the side wall of the upper structure and the structure. Since this tension member is disposed in an inclined state from the vertical direction, the horizontal response displacement of the upper structure (seismic isolation building) can be effectively suppressed using the tension member.

[0049] Also, according to another hardening type device of the present invention, the tension member is disposed with the structure side upward and the upper structure side downward in the vertical direction, and with the upper structure side closer to the lower surface corner of the upper structure and the structure side farther from the lower surface corner of the upper structure in the horizontal direction. Therefore, when the upper structure is displaced in an arbitrary horizontal direction, tension is generated only in the tension member on the side where the gap becomes smaller. For this reason, the axial force applied to the compression side laminated rubber due to the overturning moment can be reduced.

[0050] Also, according to another hardening type device of the present invention, the vertical height of the tension member is 6 times or more the gap between the side wall of the upper structure and the structure, and the horizontal length of the tension member is 2 times or more the gap between the side wall of the upper structure and the structure. Therefore, when the upper structure is displaced in an arbitrary horizontal direction, tension is generated only in the tension member on the side where the gap becomes smaller. For this reason, the axial force applied to the compression side laminated rubber due to the overturning moment can be reduced.

[0051] Also, according to another hardening type device of the present invention, since it further includes a resonance avoidance member for avoiding resonance of the tension member, resonance of the tension member can be avoided.

[0052] Also, according to the seismic isolation structure of the present invention, since it includes the above-described hardening type device, a seismic isolation structure capable of suppressing the horizontal response displacement of the upper structure can be provided.

Industrial Applicability

[0053] As described above, the curing type device according to the present invention and the seismic isolation structure provided with the same are useful for seismic isolation structures, and in particular, are suitable for effectively suppressing the horizontal response displacement of seismic isolation buildings.

Explanation of reference numerals

[0054] 10 Curing type device 12 Foundation part 14 Seismic isolation layer 16 Superstructure 18 Side wall 20 Retaining wall (structure) 22, 22a, 22b Rope material (tension member) 24 Laminated rubber (seismic isolation member) 26 Support material (resonance avoidance member) 28 Structure 30 Column 100 Seismic isolation structure a Seismic isolation layer clearance (gap) b Height of rope material c Horizontal length of rope material

Claims

1. An apparatus provided between an upper structure provided via a seismic isolation member on a base portion and a structure disposed opposite with a clearance from at least a part of a side wall of the upper structure, and used for suppressing displacement of the upper structure, comprising a tension member connecting the side wall of the upper structure and the structure, and a resonance avoidance member for avoiding resonance of the tension member, wherein the tension member is disposed in the space of the clearance in an inclined state from the vertical direction. The displacement suppression device is characterized by this.

2. The displacement suppression device according to claim 1, wherein the tension member is disposed with the structure side upward and the upper structure side downward in the vertical direction, and with the upper structure side closer to a lower surface corner portion of the upper structure and the structure side farther from the lower surface corner portion of the upper structure in the horizontal direction.

3. The displacement suppression device according to claim 1 or 2, wherein a vertical height of the tension member is 6 times or more the clearance between the side wall of the upper structure and the structure, and a horizontal length of the tension member is 2 times or more the clearance between the side wall of the upper structure and the structure.

4. A seismic isolation structure characterized by comprising the displacement suppression device according to any one of claims 1 to 3.

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