Vibration control structure

Abstract

To provide a vibration control structure capable of performing suitable vibration control according to an amount of displacement by an earthquake motion or a wind load.SOLUTION: There is provided a vibration control structure 1 including a spherical slide bearing 10 installed between a lower structure L and an upper structure U, and a long body 20 installed in parallel with the spherical slide bearing 10 between the lower structure L and the upper structure U, in which when an amount of displacement between the lower structure L and the upper structure U exceeds a predetermined amount of displacement, tensile stress is applied to the long body 20. Alternatively, the vibration control structure 1 may have a first long body and a second long body as the long body 20. When an amount of displacement between the lower structure L and the upper structure U exceeds a first predetermined amount of displacement, tensile stress is applied to the first long body. When an amount of displacement between the lower structure L and the upper structure U exceeds a second predetermined amount of displacement larger than the first predetermined amount of displacement, tensile stress is applied to the second long body.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a vibration damping structure.

Background Art

[0002] In Patent Document 1, which is an example of the prior art, there is a wind resistance device disposed in a seismic isolation layer of a seismic isolation building, including a steel first plate, a steel second plate, a first friction material disposed on one first wide surface of the first plate, a second friction material disposed on one second wide surface of the second plate, and a tightening bolt for pressing the first friction material and the second friction material that are in contact with each other. At least having, by introducing a design tension to the tightening bolt, the first friction material and the second friction material are pressed against each other with a design frictional force, and when the first friction material and the second friction material are pulled by an external force equal to or greater than the design frictional force and the contact between the first friction material and the second friction material is released, a part of the components forming the wind resistance device disengages from the initial position, thereby releasing the design tension. A wind resistance device is disclosed. The wind resistance device 100 shown in FIG. 1 of Patent Document 1 is arranged in parallel with the seismic isolation device 400.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the seismic isolation layer exemplifying the above prior art, there is a demand for a technology that enables appropriate vibration damping according to the displacement amount due to seismic motion or wind load.

[0005] The present disclosure has been made in view of such problems, and an object thereof is to provide a vibration damping structure capable of appropriate vibration damping according to the displacement amount due to seismic motion or wind load.

Means for Solving the Problem

[0006] The vibration damping structure according to one aspect of the present disclosure includes a spherical sliding bearing installed between a lower structure and an upper structure, and a long member installed in parallel with the spherical sliding bearing between the lower structure and the upper structure. When the displacement amount between the lower structure and the upper structure exceeds a predetermined displacement value, a tensile stress acts on the long member.

Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a technique that enables appropriate vibration damping according to the displacement amount caused by seismic motion or wind load.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

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Figure 7

Figure 8

MODE FOR CARRYING OUT THE INVENTION

[0009] Hereinafter, with reference to the drawings, a vibration damping structure according to an embodiment of the present disclosure will be described. FIG. 1 is a first partial elevation view showing the installation state of the vibration damping structure 1 according to the present embodiment without displacement. In FIG. 1, the thickness direction (vertical direction of the paper surface) of the upper structure U and the lower structure L is defined as the vertical direction, the extending direction (horizontal direction of the paper surface) of the upper structure U and the lower structure L is defined as the first horizontal direction, and the direction perpendicular to the vertical direction and the first horizontal direction (depth direction of the paper surface) is defined as the second horizontal direction. Also, the direction of the horizontal plane formed along the first horizontal direction and the second horizontal direction is simply referred to as the horizontal direction.

[0010] The vibration damping structure 1 shown in FIG. 1 is installed between the upper structure U and the lower structure L. The upper structure U shown in FIG. 1 is the lower part of a building, for example, the lower part of a building such as a high-rise building or a bridge. The substructure L shown in FIG. 1 is a structure disposed on the ground, for example, a foundation structure installed on the ground. Note that the substructure L is not limited to being disposed on the ground. The substructure L may be disposed, for example, above the first floor of a building. The vibration control structure 1 can also be used for intermediate layer vibration isolation and column head vibration isolation. The vibration control structure 1 shown in FIG. 1 suppresses the transmission of the horizontal displacement of the ground due to seismic motion to the building.

[0011] The vibration control structure 1 shown in FIG. 1 includes a spherical sliding bearing 10 and a long member 20. The spherical sliding bearing 10 and the long member 20 shown in FIG. 1 are installed in parallel in the first horizontal direction between the substructure L and the superstructure U.

[0012] FIG. 2 is a second partial elevation view showing the installation state of the vibration control structure 1 according to the present embodiment when there is no displacement. In the vibration control structure 1 shown in FIG. 2, a plurality of spherical sliding bearings 10 are provided. At this time, the long member 20 may be disposed between any two of the plurality of horizontally arranged spherical sliding bearings 10. For example, as shown in FIG. 2, when two of the plurality of spherical sliding bearings 10 are arranged side by side in the first horizontal direction, the long member 20 may be disposed between the two spherical sliding bearings 10 in the first horizontal direction.

[0013] First, the spherical sliding bearing 10 will be described below. The spherical sliding bearing 10 shown in FIG. 1 has a lower plate 11, a slider 12, and an upper plate 13. The lower plate 11 is a spherical seat portion disposed on the substructure L, and includes a first sliding surface 11a that is a concave spherical surface facing upward. The first sliding surface 11a is surrounded by an inner wall 11b and is a sliding surface that slides with the second sliding surface 12a of the slider 12. The lower platen 11 only needs to be fixed to the lower structure L, and the fixing means is not limited. The platen 11 may be fixed to the lower structure L by bolts as fastening means, or may be fixed by welding. The upper platen 13 is disposed under the upper structure U and has a third sliding surface 13a that is a concave spherical surface facing downward. The third sliding surface 13a is surrounded by an inner wall 13b and is a sliding surface that slides with the fourth sliding surface 12b of the slider 12. The upper platen 13 only needs to be fixed to the upper structure U, and the fixing means is not limited. The upper platen 13 may be fixed to the upper structure U by bolts as fastening means, or may be fixed by welding.

[0014] The first sliding surface 11a and the third sliding surface 13a are preferably formed in a circular shape in plan view. Also, the first sliding surface 11a and the third sliding surface 13a are formed in an arc shape in a cross-sectional view taken along the horizontal direction.

[0015] The slider 12 is disposed between the lower platen 11 and the upper platen 13 and has a second sliding surface 12a that is a convex spherical surface facing downward and a fourth sliding surface 12b that is a convex spherical surface facing upward. The second sliding surface 12a slides with the first sliding surface 11a of the lower platen 11. The fourth sliding surface 12b slides with the third sliding surface 13a of the upper platen 13.

[0016] Figure 3 is a partial elevation view showing the state of the vibration damping structure 1 according to the present embodiment during displacement. The spherical sliding bearing 10 of the vibration damping structure 1 shown in Figure 3 attenuates the horizontal displacement applied to the upper structure U and the lower structure L by the relative movement of the upper platen 13 and the lower platen 11 in the horizontal direction. At this time, when the displacement amount between the lower structure L and the upper structure U reaches a predetermined displacement value, the slider 12 abuts against the inner wall 11b and the inner wall 13b. Here, the displacement amount is the displacement amount in the horizontal direction, for example, the displacement amount in the first horizontal direction.

[0017] So far, the double pendulum type spherical sliding bearing 10 having concave spherical sliding surfaces above and below the slider 12 has been described, but the spherical sliding bearing in the present disclosure is not limited to this. That is, although the spherical sliding bearing having the lower plate 11, the upper plate 13, and the slider 12 has been described, the spherical sliding bearing in the present disclosure is not limited to this. The spherical sliding bearing 10 may be of the single pendulum type. That is, the spherical sliding bearing 10 may be provided with a spherical seat portion corresponding to the lower plate 11 having the first sliding surface 11a and the slider 12 having the second sliding surface 12a, and may not be provided with the upper plate 13 and the fourth sliding surface 12b. Alternatively, the spherical sliding bearing 10 may be provided with the upper plate 13 having the third sliding surface 13a and the slider 12 having the fourth sliding surface 12b, and may not be provided with the lower plate 11 and the second sliding surface 12a.

[0018] Next, the long body 20 will be described below. The long body 20 shown in FIG. 1 includes a rod-shaped portion 21, an enlarged portion 22, and a movement restraining member 23. The long body 20 shown in FIG. 1 connects the upper structure U and the lower structure L to restrain the movement of the upper structure U. Note that although two long bodies 20 are arranged in the first horizontal direction in FIG. 1, the number of long bodies 20 provided in the vibration control structure 1 is not limited to this, and one long body 20 may be arranged, or three or more long bodies 20 may be arranged. Also, the number of long bodies 20 arranged in parallel in the first horizontal direction and the number of long bodies 20 arranged in parallel in the second horizontal direction may be made equal. Note that the horizontal resistance force (specifically described later) by the long body 20 acts in both the first horizontal direction and the second horizontal direction. For this reason, the required number of long bodies 20 provided in the vibration control structure 1 can be obtained from the response characteristics with respect to the displacements in the first horizontal direction and the second horizontal direction of the building. Also, the arrangement of the long bodies 20 in plan view is preferably set so as to suppress the torsion of the seismic isolation layer.

[0019] Figure 4(a) is an enlarged schematic view of the elongated body 20 when the displacement amount of the vibration damping structure 1 shown in FIG. 1 is 0. Figure 4(b) is a further enlarged schematic view of the contact portion between the first enlarged portion 22a and the first movement restraining member 23a. The enlarged portions 22 shown in FIG. 4(a) are arranged at both ends or in the vicinity of both ends of each rod-shaped portion 21. The shape of the enlarged portion 22 shown in FIG. 4(a) is spherical, but the shape of the enlarged portion 22 is not limited thereto, and any shape that can contact the movement restraining member 23 is acceptable. The portion of the enlarged portion 22 that contacts the movement restraining member 23 may have, for example, a curved surface shape, and typically, a hemispherical shape or a spherical shape. This can prevent stress concentration or damage due to collision during displacement at the contact portion between the enlarged portion 22 and the movement restraining member 23. In the following description, the enlarged portion disposed above the rod-shaped portion 21 is referred to as the first enlarged portion 22a, and the enlarged portion disposed below the rod-shaped portion 21 is referred to as the second enlarged portion 22b. Also, the movement restraining member that contacts the first enlarged portion 22a is referred to as the first movement restraining member 23a, and the movement restraining member that contacts the second enlarged portion 22b is referred to as the second movement restraining member 23b.

[0020] The movement restraining members 23 are arranged on the upper structure U and the lower structure L, respectively, so as to be able to contact the enlarged portions 22. The first movement restraining member 23a shown in FIG. 4(b) is a rectangular plate provided with a through hole 24 at the center in a plan view. The first movement restraining member 23a has a spherical seat surface 25 that tapers toward the through hole 24 on the first surface A, which is one of its surfaces. On this spherical seat surface 25, the first movement restraining member 23a contacts the first enlarged portion 22a. Therefore, it is preferable that this spherical seat surface 25 has a shape along the first enlarged portion 22a. Furthermore, it is preferable that the first enlarged portion 22a and the first movement restraining member 23a are slidable. The first movement restraining member 23a may have a tapered structure that tapers toward the through hole 24 on the second surface B, which is the other surface. Although the first movement restraining member 23a has been described here, the same applies to the second movement restraining member 23b. The rod-shaped portion 21 between the first enlarged portion 22a and the second enlarged portion 22b of the elongated body 20 is inserted into the through hole 24 of the first movement restraining member 23a and the through hole 24 of the second movement restraining member 23b. Thereby, the upper structure U and the lower structure L are connected, and the movement of the upper structure U can be suppressed. That is, the first enlarged portion 22a is arranged so that its movement can be suppressed by the first movement restraining member 23a described later, and the second enlarged portion 22b is arranged so that its movement can be suppressed by the second movement restraining member 23b described later.

[0021] Here, as shown in Fig. 4(a), the vertical length between the first movement restraining member 23a and the second movement restraining member 23b when there is no displacement is defined as length L a1 and the length of the rod-shaped portion 21 between the first enlarged portion 22a and the second enlarged portion 22b when no tensile stress is acting on the elongated body 20 is defined as length L b .

[0022] As shown in Fig. 4(a), when the relationship between length L a1 and length L b is L a1 < L b , the second enlarged portion 22b does not contact the second movement restraining member 23b, and the second enlarged portion 22b is spaced downward from the second movement restraining member 23b by a length equal to the difference between L a1 and L b . At this time, the difference in length between length L a1 and length L b is referred to as the clearance.

[0023] Fig. 4(c) is a diagram showing a modified example of Fig. 4(a). As shown in Fig. 4(c), when the relationship between length L a1 and length L b is L a1 ≧ Lb When it is in such a state, the first expanding portion 22a abuts against the first movement restraining member 23a, and the second expanding portion 22b abuts against the second movement restraining member 23b.

[0024] Note that, as shown in Fig. 4(a), the length L a1 and the length L b are in a relationship of L a1 < L b When this is the case, at least one of the first movement restraining member 23a and the second movement restraining member 23b may include a disc spring.

[0025] Next, the behavior when a horizontal displacement occurs in the vibration control structure 1 according to the present embodiment will be described.

[0026] First, a displacement occurs between the upper structure U and the lower structure L due to seismic motion or wind load. At this time, let the amount of the horizontal displacement generated between the upper structure U and the lower structure L be the displacement amount δ.

[0027] Here, the behavior of the long body 20 when a displacement occurs between the lower structure L and the upper structure U will be described with reference to Figs. 5(a) and 5(b). Fig. 5(a) is an enlarged schematic view when the displacement amount δ of the long body 20 included in the vibration control structure 1 according to the present embodiment is 0. Fig. 5(b) is an enlarged schematic view when the displacement amount δ of the long body 20 included in the vibration control structure 1 according to the present embodiment is δ > 0. In Fig. 5(b), let the length between an arbitrary point P on the lower structure L and a point Q1 on the upper structure U at a position facing the point P when there is no displacement be the length L Q1 to be. When a displacement of the displacement amount δ occurs between the lower structure L and the upper structure U, the relative position of the upper structure U as seen from an arbitrary point P on the lower structure L changes from the point Q1 to the point Q2. When the length between the point P and the point Q2 is the length L Q2 to be, the length L Q1 and the length L Q2 are in a relationship of L Q1 < L Q2 to be. Therefore, the length L between the first movement restraining member 23a and the second movement restraining member 23b when there is no displacement a1 and the vertical length L between the first movement restraining member 23a and the second movement restraining member 23b when displacement occurs a2 are related such that L a1 < L a2 holds true.

[0028] When the displacement amount δ is less than the predetermined displacement value, the first enlarged portion 22a does not contact the first movement restraining member 23a, and the second enlarged portion 22b does not contact the second movement restraining member 23b. In FIG. 5(b), when the displacement amount δ reaches the predetermined displacement value, the length L a2 and the length L b are related such that L a2 = L b holds true, and the first enlarged portion 22a contacts the first movement restraining member 23a, and the second enlarged portion 22b contacts the second movement restraining member 23b, thereby suppressing the movement of the upper structure U. Furthermore, when the displacement amount δ exceeds the predetermined displacement value, the length L a2 and the length L b are related such that L a2 > L b holds true, and a tensile stress acts on the long body 20.

[0029] When a tensile stress acts on the long body 20, a horizontal resistance force and a vertical resistance force are generated in the long body 20. Here, the horizontal component of the tensile stress when a tensile stress acts on the long body 20 is expressed as the horizontal resistance force (restoring force), and the vertical component of the tensile stress is expressed as the vertical resistance force (additional axial force).

[0030] FIG. 6(a) is a diagram showing the relationship between the restoring force G acting on the spherical sliding bearing 10 with respect to the displacement amount δ when only the spherical sliding bearing 10 is arranged in the seismic isolation layer. 1 is a diagram showing the relationship. Here, the restoring force refers to the force that attempts to pull an object back to its original position when the position of the object deviates from a certain place. In the seismic isolation layer, the restoring force G 1 acting on the vibration control structure 1 acts as a displacement damping force. The restoring force G 1increases as the displacement amount δ increases.

[0031] Figure 6(b) is a diagram showing the relationship between the restoring force (horizontal resistance force) G acting on the long body 20 with respect to the displacement amount δ 2 of the long body 20. Figure 6(c) is a diagram showing the relationship between the additional axial force (vertical resistance force) G acting on the long body 20 with respect to the displacement amount δ 3 of the long body 20. As shown in FIGS. 6(b) and 6(c), until the displacement amount exceeds the predetermined displacement value δ 3 no tensile stress acts on the long body 20. Let the displacement amount at the yield of the rod-shaped portion 21 of the long body 20 be δ 1 and the displacement amount at the breakage of the rod-shaped portion 21 be δ 2 .

[0032] Next, the horizontal displacement occurrence will be described by dividing it into the first embodiment where L a1 < L b and the second embodiment where L a1 = L b .

[0033] (First embodiment where L a1 < L b ) When the relationship between the length L a1 and the length L b is L a1 < L b and the displacement amount δ between the lower structure L and the upper structure U is less than the predetermined displacement value δ 3 , the second enlarged portion 22b does not contact the second movement suppressing member 23b. When the displacement amount δ between the lower structure L and the upper structure U reaches the predetermined displacement value δ 3 , the second enlarged portion 22b contacts the second movement suppressing member 23b. That is, the predetermined displacement value δ 3 refers to the displacement amount when the relationship between the length L a2 and the length L b is L a2 = L b , and the predetermined displacement value δ 3 is an arbitrary value of 0 or more. The predetermined displacement value δ 3 is, for example, the length La1 and the length L b It can be adjusted by the clearance which is the difference in length from

[0034] Therefore, even when displacement occurs due to wind load or seismic motion, etc., as long as the displacement amount δ does not exceed the predetermined displacement value δ 3 tensile stress does not act on the long body 20. Therefore, until the displacement amount δ exceeds the predetermined displacement value δ 3 no additional axial force (vertical resistance force) of the long body 20 acts on the spherical sliding bearing 10, and the slider 12 of the spherical sliding bearing 10, the upper plate 13, and the lower plate 11 freely move relative to each other according to the displacement amount. At this time, a horizontal force that tries to return to the center of the concave spherical surface of the first sliding surface 11a and the third sliding surface 13a acts on the slider 12. In this way, a restoring force is generated in the spherical sliding bearing 10.

[0035] When a force acts such that the displacement amount δ between the lower structure L and the upper structure U exceeds the predetermined displacement value δ 3 tensile stress acts on the long body 20. At this time, the vertical resistance force of the long body 20 acts as an additional axial force on the spherical sliding bearing 10, suppressing the horizontal movement between the upper plate 13 and the lower plate 11 of the spherical sliding bearing 10. As a result, the long body 20 suppresses the movement of the seismic isolation layer and suppresses the movement of the spherical sliding bearing 10 and the long body 20.

[0036] In the first embodiment, the case where the predetermined displacement value δ 3 is the equivalent amount of the maximum displacement δ LV2 in the level 2 seismic motion will be described, but the present disclosure is not limited to the case where the predetermined displacement value is the equivalent amount of the maximum displacement δ LV2 in the level 2 seismic motion. The predetermined displacement value δ 3 may be, for example, the equivalent amount of the maximum displacement in other levels of seismic motion, or may be, for example, the equivalent amount of the maximum displacement in seismic motion of level 2 or lower. Here, the "level" of seismic motion is an index indicating the intensity of seismic motion. Regarding the "level" of an earthquake, according to the description in the "Technical Standards Explanation Book on Building Structures, 2020 Edition" (edited by the General Incorporated Foundation Architectural Administrative Information Center and the General Incorporated Foundation Japan Building Disaster Prevention Association; page 71), it is defined as follows. That is, earthquake motion with a seismic intensity that occurs extremely rarely, about once every 50 years, is defined as Level 1 earthquake motion. Level 1 earthquake motion is highly likely to occur more than once during the service life of a building. In addition, earthquake motion with a seismic intensity that occurs extremely rarely, about once every 500 years, is defined as Level 2 earthquake motion. Furthermore, earthquake motion with a maximum seismic intensity larger in scale than Level 2 earthquake motion is defined as Level 3 earthquake motion.

[0037] Figure 7(a) is a diagram showing the restoring forces of the spherical sliding bearing 10 and the long body 20 with respect to the displacement amount δ of the vibration control structure 1 according to the present embodiment. In Figure 7(a), the restoring force G 1 represents the restoring force of the spherical sliding bearing 10 with respect to the displacement amount δ of the vibration control structure 1. In Figure 7(a), the restoring force G 2 represents the restoring force of the long body 20 with respect to the displacement amount δ of the vibration control structure 1. In Figure 7(a), the additional axial force G 3 represents the additional axial force applied to the spherical sliding bearing 10 by the long body 20 with respect to the displacement amount δ of the vibration control structure 1. As shown in Figure 7(a), until the displacement amount δ reaches the maximum displacement equivalent amount δ 3 in Level 2 earthquake motion, where the displacement amount δ is from 0 to a predetermined displacement value δ LV2 no restoring force is generated in the long body 20, and only the restoring force G 1 is generated in the spherical sliding bearing 10. When the displacement amount δ exceeds the maximum displacement equivalent amount δ LV2 in Level 2 earthquake motion, not only in the spherical sliding bearing 10 but also in the long body 20, the restoring force G 2 is generated. And when the displacement amount δ exceeds the maximum displacement equivalent amount δ LV2 in Level 2 earthquake motion, in the spherical sliding bearing 10, due to the tensile stress of the long body 20, the additional axial force G 3 also acts.

[0038] Figure 7(b) is a diagram showing the restoring force of the entire vibration damping structure 1 with respect to the displacement amount δ of the vibration damping structure 1 according to the present embodiment. In Figure 7(b), the restoring force G 5 represents the restoring force of the entire vibration damping structure 1 with respect to the displacement amount δ of the vibration damping structure 1. As shown in Figure 7(b), when a tensile stress acts on the long body 20 at a displacement amount δ exceeding a predetermined displacement value δ 3 , the restoring force of the entire vibration damping structure 1 is improved.

[0039] Specifically, in the present embodiment, until the displacement amount δ reaches from 0 to the predetermined displacement value δ 3 (the equivalent maximum displacement amount δ LV2 in level 2 earthquake motion), only the spherical sliding bearing 10 damps vibration, and the restoring force G 5 changes in the same manner as the restoring force G 1 . The behavior when only the spherical sliding bearing 10 is damping vibration is the same as that of the conventional vibration damping by the spherical sliding bearing. Then, when the displacement amount δ exceeds the predetermined displacement value δ 3 (the equivalent maximum displacement amount δ LV2 in level 2 earthquake motion), a tensile stress acts on the long body 20. The tensile stress acting on the long body 20 brings about an additional axial force G 3 and a restoring force G 2 .

[0040] At this time, the restoring force G 2 generated by the long body 20, together with the restoring force G 1 generated by the spherical sliding bearing 10, attenuates the displacement between the lower structure L and the upper structure U. Therefore, a restoring force corresponding to the restoring force G 1 is added to the restoring force G 2 .

[0041] In addition, the vertical resistance force by the long body 20 becomes the additional axial force G 3 to the spherical sliding bearing 10. When an additional axial force is applied to the spherical sliding bearing 10 by the long member 20, the slider 12 is pressed against the upper plate 13 and the lower plate 11. As a result, the frictional force generated between the slider 12, the upper plate 13, and the lower plate 11 increases. When the frictional force generated in the spherical sliding bearing 10 increases, the relative movement of the spherical sliding bearing 10 is suppressed.

[0042] Thus, in the vibration damping structure 1, when a tensile stress acts on the long member 20 with a displacement amount exceeding a predetermined displacement value δ 3 not only the restoring force G 2 but also the additional axial force G 3 will suppress the relative movement of the spherical sliding bearing 10.

[0043] (L a1 = L b in the second embodiment) Length L a1 and length L b are in the relationship of L a1 = L b when the first enlarged portion 22a abuts against the first movement suppressing member 23a and the second enlarged portion 22b abuts against the second movement suppressing member 23b. At this time, the predetermined displacement value δ 3 is 0. Therefore, when the displacement amount exceeds 0, a tensile stress acts on the long member 20.

[0044] FIG. 8 is a diagram showing the restoring force of the entire vibration damping structure 1 with respect to the displacement amount δ of the vibration damping structure 1 according to the present embodiment. In FIG. 8, the restoring force G 6 is a diagram showing the restoring force of the entire vibration damping structure 1 with respect to the displacement amount δ of the vibration damping structure 1.

[0045] The behavior of the entire vibration damping structure 1 due to the tensile stress acting on the long member 20 is as described above, but in the present embodiment, the predetermined displacement value is 0. Therefore, even for a slight displacement amount due to wind load or the like, if a displacement occurs between the lower structure L and the upper structure U, a tensile stress acts on the long member 20. In addition to suppressing the relative movement of the seismic isolation layer due to the horizontal resistance of the long body 20, the relative movement of the spherical sliding bearing 10 is suppressed by the above-described additional axial force, thereby suppressing the seismic isolation layer from starting to move due to a relatively small external force such as a wind load. Restoring force G shown in FIG. 8 6 At the initial stage where the displacement amount δ is small, in addition to the restoring force G 1 In addition to the restoring force G 2 and the additional axial force G 3 are added. Specifically, since the predetermined displacement value δ 3 is 0, a tensile stress acts on the long body 20 even due to a relatively small external force such as a wind load. At this time, a restoring force G 1 due to the tensile stress acting on the long body 20 is added to the restoring force G 2 acting on the long body 20.

[0046] In the present embodiment, the long body 20 yields when the tensile stress acting on the long body 20 exceeds a predetermined stress value, and the displacement amount at this time is defined as a predetermined displacement value δ 1 and. That is, the long body 20 yields when it exceeds the predetermined displacement value δ 1 exceeds. Further, in the present embodiment, the long body 20 breaks when the tensile stress acting on the long body 20 exceeds a predetermined stress value, and the displacement amount at this time is defined as a predetermined displacement value δ 2 and. That is, the long body 20 breaks when it exceeds the predetermined displacement value δ 2 exceeds. As shown in FIG. 8, when the long body 20 breaks after exceeding the predetermined displacement value δ 2 , the restoring force of the entire vibration control structure 1 becomes only the restoring force of the spherical sliding bearing 10. Therefore, when it exceeds the predetermined displacement value δ 2 , the restoring force G 6 changes in the same manner as the restoring force G 1 shown in FIG. 6(a) and the like.

[0047] When the long body 20 breaks, the additional axial force G 3The increase in frictional force in the spherical sliding bearing 10 due to [cause] disappears, and the friction in the spherical sliding bearing 10 is reduced, so that the spherical sliding bearing 10 can move relatively greatly. Thus, when a large earthquake motion that causes a displacement amount exceeding a predetermined displacement value δ 2 occurs, the long member 20 breaks, and a large relative movement of the spherical sliding bearing 10 becomes possible. The large relative movement of the spherical sliding bearing 10 reduces the influence on the building by making the natural period of the building on the superstructure U longer.

[0048] In this embodiment, the length L a1 and the length L b are described in the case of L a1 = L b However, the relationship between the length L a1 and the length L b can be, for example, L a1 > L b as well. When the relationship between the length L a1 and the length L b is L a1 > L b the first enlarged portion 22a abuts against the first movement restraining member 23a, the second enlarged portion 22b abuts against the second movement restraining member 23b, and a certain initial tension exists in the long member 20 even when the displacement amount is 0. At this time, when the displacement amount reaches a predetermined displacement value, the tensile stress in the long member 20 increases.

[0049] Further, at least one of the first movement restraining member 23a and the second movement restraining member 23b may include a disc spring.

[0050] (Hereinafter, an embodiment common to the first embodiment and the second embodiment) Note that the vibration control structure 1 only needs to include at least one spherical sliding bearing 10 and at least one long member 20, and the number and arrangement thereof are not limited. For example, the vibration damping structure 1 may include a spherical sliding bearing 10 installed between the lower structure L and the upper structure U, and a first elongated body and a second elongated body which are elongated bodies 20 installed in parallel with the spherical sliding bearing 10 between the lower structure L and the upper structure U. For example, the vibration damping structure 1 may have a plurality of spherical sliding bearings, and may include two spherical sliding bearings 10 arranged horizontally between the lower structure L and the upper structure U, and an elongated body 20 disposed between the two spherical sliding bearings 10.

[0051] At this time, preferably, when the displacement amount between the lower structure L and the upper structure U exceeds a first predetermined displacement value, a tensile stress acts on the first elongated body, and when the displacement amount between the lower structure L and the upper structure U exceeds a second predetermined displacement value that is larger than the first predetermined displacement value, a tensile stress acts on the second elongated body. Thereby, each elongated body functions stepwise, and multi-stage vibration damping according to the displacement amount becomes possible.

[0052] Here, the first predetermined displacement value is not particularly limited, and may be, for example, 0. Alternatively, the first predetermined displacement value may be, for example, an equivalent amount of the maximum displacement in seismic motion of level 2 or lower. Also, the second predetermined displacement value is not particularly limited, and may be, for example, an equivalent amount of the maximum displacement in seismic motion of level 3 or lower.

[0053] As described above, the vibration damping structure 1 of the present embodiment includes a spherical sliding bearing 10 installed between the lower structure L and the upper structure U, and an elongated body 20 installed in parallel with the spherical sliding bearing 10 between the lower structure L and the upper structure U. When the displacement amount between the lower structure L and the upper structure U exceeds a predetermined displacement value, a tensile stress acts on the elongated body 20.

[0054] Conventionally, for the purpose of protecting a building against seismic motion, a seismic isolation layer may be provided in the building. Buildings equipped with a seismic isolation layer are designed considering seismic motions that occur rarely about once every 50 years (Level 1 seismic motion) and extremely rarely about once every 500 years (Level 2 seismic motion). Various vibration control structures have been proposed as devices used for such seismic isolation layers.

[0055] However, when a seismic motion that occurs extremely rarely (Level 3 seismic motion) exceeding the Level 2 seismic motion occurs, it is difficult for conventional vibration control structures to sufficiently reduce the seismic motion. Therefore, as a method to enable following large displacements such as Level 3 seismic motion using a conventional vibration control structure, it is conceivable to increase the device size (concave plate size). However, increasing the device size in this way causes an increase in the overall construction cost due to an increase in the amount of excavated soil and construction cost.

[0056] Furthermore, for example, in a building where a conventional sliding bearing is installed, considering appropriate vibration control against seismic motion, the damping of the seismic isolation layer should be reduced and the seismic isolation layer should slide more. However, if the damping of the seismic isolation layer is reduced, the seismic isolation layer will start to move even by a relatively small external force such as wind load, making it difficult to suppress the displacement of the upper structure U.

[0057] The vibration control structure 1 according to this embodiment includes a long body 20 installed in parallel with the spherical sliding bearing 10. When the displacement amount between the lower structure L and the upper structure U exceeds a predetermined displacement value, a tensile stress acts on the long body 20. At this time, the tensile stress acting on the long body 20 brings about a vertical resistance force and a horizontal resistance force. The horizontal resistance force generated by the long body 20, together with the restoring force generated by the spherical sliding bearing 10, attenuates the displacement between the lower structure L and the upper structure U. Also, the vertical resistance force by the long body 20 acts as an additional axial force on the spherical sliding bearing 10. When an additional axial force is applied to the spherical sliding bearing 10 by the long member 20, the slider 12 is pressed against the upper plate 13 and the lower plate 11, and the frictional force generated between the slider 12 and the upper plate 13 and the lower plate 11 increases. When the frictional force generated in the spherical sliding bearing 10 increases, the relative movement of the spherical sliding bearing 10 is suppressed by this frictional force. Thereby, even when a large displacement exceeding a predetermined displacement value occurs due to, for example, seismic motion, excessive deformation of the seismic isolation layer can be suppressed and the displacement can be attenuated. Therefore, by this, for example, it is possible to cope with level 3 seismic motion and perform stepwise vibration control according to the amount of displacement.

[0058] Furthermore, when the amount of displacement between the lower structure L and the upper structure U reaches a predetermined displacement value, the tensile stress of the long member 20 increases. When the tensile stress of the long member 20 increases, the horizontal resistance force and the vertical resistance force acting on the long member 20 increase. When the horizontal resistance force acting on the long member 20 increases, the damping performance with respect to the displacement between the lower structure L and the upper structure U is improved, and the additional axial force applied to the spherical sliding bearing 10 by the vertical resistance force acting on the long member 20 increases, and the slider 12 is pressed against the upper plate 13 and the lower plate 11, and the frictional force generated between the slider 12 and the upper plate 13 and the lower plate 11 increases, whereby the relative movement of the spherical sliding bearing 10 is more strongly suppressed. Thereby, even when a large displacement amount exceeding a predetermined displacement value occurs due to, for example, seismic motion, excessive deformation of the seismic isolation layer is suppressed and the displacement can be further attenuated.

[0059] The spherical sliding bearing 10 includes a spherical seat portion 11 having a first sliding surface 11a surrounded by an inner wall 11b, and a slider 12 having a second sliding surface 12a that slidably contacts the first sliding surface 11a. The slider 12 and the inner wall 11b come into contact with each other when the amount of displacement between the lower structure L and the upper structure U reaches a predetermined displacement value. Thereby, it is possible to prevent the slider 12 of the spherical sliding bearing 10 from falling off the spherical seat portion 11 with respect to a displacement amount of a certain level or more.

[0060] Also, a plurality of spherical sliding bearings 10 may be provided, and the long member 20 may be disposed between any two of the plurality of spherical sliding bearings 10 arranged side by side in the horizontal direction. For example, when the long member 20 is disposed eccentrically in plan view, the upper structure of the building or the like may be deformed and the vertical resistance may not be transmitted to the spherical sliding bearing 10. However, by adopting a structure in which the long member 20 is disposed between any two of the plurality of spherical sliding bearings 10, the vertical resistance by the long member 20 can be more reliably transmitted to the spherical sliding bearing 10.

[0061] Further, the long member 20 includes a first enlarged portion 22a disposed on one end side and a second enlarged portion 22b disposed on the other end side. The upper structure U is provided with a first movement suppressing member 23a capable of suppressing the movement of the first enlarged portion 22a, and the lower structure L is provided with a second movement suppressing member 23b capable of suppressing the movement of the second enlarged portion 22b. When the displacement amount between the lower structure L and the upper structure U is less than a predetermined displacement value, the second enlarged portion 22b does not contact the second movement suppressing member 23b, and when the displacement amount between the lower structure L and the upper structure U reaches the predetermined displacement value, the second enlarged portion 22b contacts the second movement suppressing member 23b. Such a structure may be adopted. With such a structure, when the displacement amount between the lower structure L and the upper structure U is less than the predetermined displacement value, the second enlarged portion 22b does not contact the second movement suppressing member 23b, and when the displacement amount between the lower structure L and the upper structure U reaches the predetermined displacement value, the second enlarged portion 22b contacts the second movement suppressing member 23b. Thereby, when the displacement amount is less than or equal to the predetermined displacement value, the vibration damping structure 1 is damped only by the spherical sliding bearing 10, and when the displacement amount exceeds the predetermined displacement value, the spherical sliding bearing 10 and the long member 20 cooperate to enable attenuation of the displacement. That is, the building can be damped by the entire vibration damping structure 1 according to the magnitude of the displacement amount. Therefore, it is possible to enable stepwise vibration damping according to the displacement amount.

[0062] Further, the predetermined displacement value may correspond to the maximum displacement equivalent amount. For example, the predetermined displacement value may be the maximum displacement equivalent amount in seismic motion of level 2 or lower. With such a structure, for example, when the predetermined displacement value is the maximum displacement equivalent amount of level 2 seismic motion, for level 2 seismic motion, vibration control is performed only by the spherical sliding bearing 10, and for level 3 seismic motion exceeding level 2 seismic motion, the long body 20 and the spherical sliding bearing 10 cooperate to enable displacement attenuation. For example, when the predetermined displacement value is the maximum displacement equivalent amount of level 1 seismic motion, the vibration control structure 1 performs vibration control only by the spherical sliding bearing 10 for level 1 seismic motion, and for level 2 seismic motion exceeding level 1 seismic motion, the long body 20 and the spherical sliding bearing 10 cooperate to enable displacement attenuation. Therefore, it is possible to perform stepwise vibration control according to the displacement amount for each level of seismic motion.

[0063] Also, in this configuration, the predetermined displacement value may be 0. With such a configuration, tensile stress acts on the long body 20 even for a slight displacement amount due to wind load or the like. In addition to suppressing the relative movement of the seismic isolation layer by the horizontal resistance of the long body 20, the relative movement of the spherical sliding bearing 10 is suppressed by the aforementioned additional axial force. Therefore, the seismic isolation layer is suppressed from starting to move due to a relatively small external force such as wind load.

[0064] Also, an initial tension may exist in the long body 20. With such a configuration, it is possible to more strongly suppress the seismic isolation layer from starting to move due to an external force.

[0065] Further, the long body 20 includes a first enlarged portion 22a disposed on one end side and a second enlarged portion 22b disposed on the other end side. The upper structure U is provided with a first movement suppressing member 23a that suppresses the movement of the first enlarged portion 22a, and the lower structure L is provided with a second movement suppressing member 23b that suppresses the movement of the second enlarged portion 22b. The first enlarged portion 22a may contact the first movement suppressing member 23a, and the second enlarged portion 22b may contact the second movement suppressing member 23b. With such a configuration, tensile stress acts on the long member 20 even for a slight displacement amount caused by wind load or the like. In addition to suppressing the relative movement of the seismic isolation layer by the horizontal resistance of the long member 20, the relative movement of the spherical sliding bearing 10 is suppressed by the aforementioned additional axial force. Therefore, the seismic isolation layer is suppressed from starting to move due to a relatively small external force such as wind load.

[0066] Also, the long member 20 may break when the tensile stress acting on the long member 20 exceeds a predetermined stress value. When the long member 20 breaks, the increase in the frictional force in the spherical sliding bearing 10 generated by the long member 20 is released, and the frictional force in the spherical sliding bearing 10 is reduced, so that the spherical sliding bearing 10 moves relatively greatly. Thus, when a large earthquake motion that causes a displacement amount exceeding the predetermined stress value occurs, the long member 20 breaks, and a large relative movement of the spherical sliding bearing 10 becomes possible. The large relative movement of the spherical sliding bearing 10 reduces the influence on the building by making the natural period of the building on the upper structure U longer. Therefore, it is possible to enable stepwise vibration control according to the displacement amount.

[0067] Also, at least one of the first movement suppressing member 23a and the second movement suppressing member 23b may include a disc spring. With such a configuration, for example, when the displacement value is equal to or less than a predetermined displacement value, while allowing a certain relative movement of the long member 20, the movement of the seismic isolation layer can be suppressed by the elastic force of the disc spring. Therefore, it is possible to enable stepwise vibration control according to the displacement value.

[0068] Also, a spherical sliding bearing 10 installed between the lower structure L and the upper structure U, and a first elongated body and a second elongated body which are elongated bodies 20 installed in parallel with the spherical sliding bearing 10 between the lower structure L and the upper structure U. The vibration damping structure 1 is configured such that when the displacement amount between the lower structure L and the upper structure U exceeds a first predetermined displacement value, a tensile stress acts on the first elongated body, and when the displacement amount between the lower structure L and the upper structure U exceeds a second predetermined displacement value that is larger than the first predetermined displacement value, a tensile stress may act on the second elongated body. With such a configuration, when the displacement amount is equal to or less than the first predetermined displacement value, only the spherical sliding bearing 10 of the vibration damping structure 1 damps vibration. When the displacement amount exceeds the first predetermined displacement value and is equal to or less than the second predetermined displacement value, the spherical sliding bearing 10 and the first elongated body damp vibration. When the displacement amount exceeds the second predetermined displacement value, the spherical sliding bearing 10, the first elongated body, and the second elongated body damp vibration. Therefore, it is possible to perform stepwise vibration damping according to the displacement amount.

[0069] Also, the first predetermined displacement value may be 0 in this configuration. With such a configuration, a tensile stress acts on the first elongated body even for a slight displacement amount due to a wind load or the like. In addition to suppressing the relative movement of the seismic isolation layer by the horizontal resistance of the first elongated body, the relative movement of the spherical sliding bearing 10 is suppressed by the aforementioned additional axial force. Therefore, it is possible to suppress the seismic isolation layer from starting to move due to a relatively small external force such as a wind load.

[0070] Also, the first predetermined displacement value may be an equivalent amount of the maximum displacement in seismic motion of level 2 or lower, and the second predetermined displacement value may be an equivalent amount of the maximum displacement in seismic motion of level 3 or lower. With such a configuration, for example, a tensile stress acts only on the first elongated body for a displacement amount exceeding the equivalent amount of the maximum displacement in seismic motion of level 2 or lower, and for a displacement amount exceeding the equivalent amount of the maximum displacement in seismic motion of level 3 or lower, a tensile stress acts on the second elongated body in addition to the first elongated body. As a result, each elongated body acts stepwise, and it is possible to perform stepwise vibration damping according to the displacement amount.

[0071] Further, at least one of the surfaces of the first enlarged portion 22a and the second enlarged portion 22b may have a curved surface shape. With such a configuration, it is possible to prevent damage due to stress concentration or collision during displacement at the contact portion between the enlarged portion 22 and the movement restraining member 23.

[0072] Further, at least one of the first enlarged portion 22a and the second enlarged portion 22b may be spherical. With such a configuration, the contact angle between the enlarged portion 22 and the movement restraining member 23 can be freely changed.

[0073] Further, the rod-shaped portion 21 between the first enlarged portion 22a and the second enlarged portion 22b of the elongated body 20 may be inserted into at least one of the first movement restraining member 23a and the second movement restraining member 23b. With such a configuration, the rod-shaped portion 21 can be arranged so as to connect the upper structure U and the lower structure L.

[0074] Note that the technical scope of the present disclosure is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present disclosure.

[0075] Note that the elongated body 20 does not necessarily have to be directly installed on the lower structure L and the upper structure U, and may be installed via a connecting member arranged on the lower structure L and the upper structure U, for example.

[0076] In addition, within the scope not departing from the spirit of the present disclosure, it is possible to appropriately replace the components in the above-described embodiment with well-known components, and the above-described modification examples may be appropriately combined.

Explanation of Reference Numerals

[0077] 1 Vibration damping structure 10 Spherical sliding bearing 11 Bottom board 11a First sliding surface 11b Inner wall 12 Slider 12a Second sliding surface 12b Fourth sliding surface 13 Upper plate 13a Third sliding surface 13b Inner wall 20 Long body 21 Rod-shaped part 22 Enlarged part 22a First enlarged part 22b Second enlarged part 23 Movement restraining member 23a First movement restraining member 23b Second movement restraining member 24 Through hole 25 Ball seat surface U Upper structure L Lower structure

Claims

1. A spherical sliding bearing installed between a lower structure and an upper structure, A long member installed in parallel with the spherical sliding bearing between the lower structure and the upper structure, Comprising, When the displacement amount between the lower structure and the upper structure exceeds a predetermined displacement value, a tensile stress acts on the long member, A vibration damping structure.

2. When the displacement amount between the lower structure and the upper structure reaches the predetermined displacement value, the tensile stress in the long member increases, The vibration damping structure according to claim 1.

3. The spherical sliding bearing, A spherical seat portion having a first sliding surface surrounded by an inner wall, A slider having a second sliding surface that slidably contacts the first sliding surface, The slider and the inner wall are in contact with each other when the displacement amount between the lower structure and the upper structure reaches the predetermined displacement value, The vibration damping structure according to claim 1.

4. A plurality of the spherical sliding bearings are provided, The long member is arranged between two of the plurality of spherical sliding bearings arranged side by side in the horizontal direction, The vibration damping structure according to claim 1.

5. When the displacement amount between the lower structure and the upper structure reaches the predetermined displacement value, the movement of the long member is suppressed. The vibration damping structure according to claim 1.

6. The long member, A first enlarged portion arranged on one end side, A second enlarged portion arranged on the other end side, A first movement restraining member capable of restraining the movement of the first enlarged portion is provided on the upper structure, A second movement restraining member capable of restraining the movement of the second enlarged portion is provided on the lower structure, When the displacement amount between the lower structure and the upper structure is less than the predetermined displacement value, the second enlarged portion does not contact the second movement restraining member, When the displacement amount between the lower structure and the upper structure reaches the predetermined displacement value, the second enlarged portion contacts the second movement restraining member, The vibration damping structure according to claim 1.

7. The predetermined displacement value is the maximum displacement equivalent amount in ground motions of level 2 or less. The vibration damping structure according to claim 1.

8. The predetermined displacement value corresponds to the maximum displacement equivalent amount, The vibration damping structure according to claim 6.

9. The predetermined displacement value is 0. The vibration damping structure according to claim 1.

10. An initial tension exists in the long member. The vibration damping structure according to claim 6.

11. The long member, A first enlarged portion arranged on one end side, A second enlarged portion arranged on the other end side, The upper structure is provided with a first movement restraining member that restrains the movement of the first enlarged portion. The lower structure is provided with a second movement restraining member that restrains the movement of the second enlarged portion. The first enlarged portion abuts against the first movement restraining member, and the second enlarged portion abuts against the second movement restraining member. The vibration damping structure according to claim 1.

12. The vibration damping structure according to claim 6 or claim 11, wherein the elongated body breaks when the tensile stress acting on the elongated body exceeds a predetermined stress value.

13. The vibration damping structure according to claim 6 or claim 11, wherein at least one of the first movement restraining member and the second movement restraining member includes a disc spring.

14. A spherical sliding bearing installed between the lower structure and the upper structure, A first elongated body and a second elongated body, which are elongated bodies installed in parallel with the spherical sliding bearing between the lower structure and the upper structure, Comprising: When the displacement amount between the lower structure and the upper structure exceeds a first predetermined displacement value, a tensile stress acts on the first elongated body. When the displacement amount between the lower structure and the upper structure exceeds a second predetermined displacement value greater than the first predetermined displacement value, a tensile stress acts on the second elongated body. Vibration damping structure.

15. The vibration damping structure according to claim 14, wherein the first predetermined displacement value is 0.

16. The first predetermined displacement value is an equivalent amount of the maximum displacement in seismic motion of level 2 or lower, The vibration damping structure according to claim 14, wherein the second predetermined displacement value is an equivalent amount of the maximum displacement in seismic motion of level 3 or lower.

17. The vibration damping structure according to claim 6 or claim 11, wherein at least one of the surfaces of the first enlarged portion and the second enlarged portion has a curved surface shape.

18. The vibration damping structure according to claim 6 or claim 11, wherein at least one of the first enlarged portion and the second enlarged portion is spherical.

19. The vibration damping structure according to claim 6 or claim 11, wherein a rod-shaped portion between the first enlarged portion and the second enlarged portion of the elongated body is inserted into at least one of the first movement restraining member and the second movement restraining member.

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