Vibration damping structure

Abstract

This invention provides a vibration-damping structure that can reduce the shear force on the substructure in large-span buildings. [Solution] The vibration damping structure comprises a substructure 2 and a roof structure 3 supported by the substructure 2, and the rigidity of the layer 31A including the columns 31 of the roof structure 3 is determined so that the period of the roof structure 3 is synchronized with the period of the substructure 2.

Description

[Technical Field]

[0001] This invention relates to a vibration damping structure. [Background technology]

[0002] Conventionally, in the seismic design of domes, arenas, and other structures, the adoption of base isolation and vibration control structures has been considered to reduce the horizontal loads generated on the roof structure and substructure due to seismic motion.

[0003] For example, Patent Document 1 below discloses a system in which seismic isolation devices are placed on the support sections of a roof structure. This is expected to reduce the horizontal loads and accelerations generated in the roof structure. On the other hand, the reduction effect on horizontal loads and accelerations generated in the stand section may not be sufficient, and for improved safety and economic design, it is desirable to adopt a frame system that has a greater response reduction effect in the stand section.

[0004] In recent years, a type of TMD (Tuned Mass Damper), called a Building Mass Damper (BMD), has been proposed, which uses a part of the building as a weight to synchronize with the substructure, and is being applied to actual buildings. Patent Document 2 below discloses a system that uses the upper floors of a high-rise building as a weight and employs seismic isolation devices for stiffness tuning. Patent Document 3 below discloses a system that uses an extension added to the upper floors of a high-rise building as a weight and uses pin connections at the column bases of the lowest floor of the extension for stiffness tuning. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 8-326351 [Patent Document 2] Japanese Patent Publication No. 62-273374 [Patent Document 3] Japanese Patent Publication No. 2024-83743 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, while a vibration control method that uses the roof of a large-span building as a counterweight to synchronize with the stand section is expected to have a significant effect in reducing the response of the stand section, no such structural form has yet been proposed, and a design method has not yet been established. Furthermore, large-span buildings have a shorter natural period of around 1 second for their substructure compared to skyscrapers. Therefore, the seismic isolation devices typically used in BMD (Building Mass Diversion) for skyscrapers are not necessarily suitable for tuning the rigidity of the members supporting the roof.

[0007] Therefore, the present invention has been made in view of the above circumstances, and provides a vibration control structure that can reduce the shear force on the substructure in a large-span building. [Means for solving the problem]

[0008] To achieve the above objective, the present invention employs the following means. In other words, the vibration damping structure according to the present invention comprises a substructure and a roof structure supported by the substructure, wherein the rigidity of the layer including the columns of the roof structure is determined so as to synchronize the period of the roof structure with the period of the substructure.

[0009] In a vibration-damping structure configured in this way, the shear force on the substructure can be reduced in large-span buildings by determining the rigidity of the layers including the roof structure columns so that the period of the roof structure is synchronized with the period of the substructure.

[0010] Furthermore, in the vibration damping structure according to the present invention, the joint between the upper part of the column of the roof structure and the horizontal member of the roof structure may be a pin joint.

[0011] In this type of vibration-damping structure, the upper part of the columns of the roof structure and the horizontal members of the roof structure are pin-connected, allowing the period of the roof structure to be synchronized with the period of the substructure.

[0012] In addition, for the vibration damping structure according to the present invention, the optimal rigidity k opt is represented by Formula (1), and the optimal damping c opt is represented by Formula (2). A viscous damper may be arranged in parallel with the column in the layer including the column of the roof structure body.

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[0013] In addition, for the vibration damping structure according to the present invention, with the rigidity of the layer including the column of the roof structure body being k and the damping coefficient of the layer including the column of the roof structure body being c, k / k opt = 0.5 to 2.0, c / c opt ≤ 5.0 may be satisfied.

[0014] In the vibration damping structure configured as such, by setting k / k opt = 0.5 to 2.0, c / c opt ≤ 5.0, the period of the roof structure body can be synchronized with the period of the lower structure body.

[0015] In the vibration damping structure configured as such, while setting the optimal rigidity k opt and the optimal damping c opt and arranging a viscous damper in parallel with the column, the period of the roof structure body can be synchronized with the period of the lower structure body.

[0016] In addition, for the vibration damping structure according to the present invention, in the layer including the column of the roof structure body, a viscous damper and an inertial mass damper may be arranged and connected in parallel at the lower part of the column.

[0017] In the vibration damping structure configured as such, by arranging and connecting a viscous damper and an inertial mass damper in parallel at the lower part of the column, the period of the roof structure body can be synchronized with the period of the lower structure body.

Effect of the Invention

[0018] According to the vibration damping structure of the present invention, in a large - space building, the shear force of the lower structure body can be reduced. [Brief explanation of the drawing]

[0019] [Figure 1] This is a schematic diagram showing a vibration damping structure according to the first embodiment of the present invention. [Figure 2] This is a schematic diagram showing the phase difference of vibrations in a vibration damping structure according to the first embodiment of the present invention. [Figure 3] This is a schematic top view showing the roof structure of a building with a vibration-damping structure according to a second embodiment of the present invention. [Figure 4] This is a schematic elevation view of section IV in Figure 3, enlarged. [Figure 5] This diagram shows the details of the joint between the upper chord and the column. [Figure 6] This is a cross-sectional view taken along the line VI-VI in Figure 5. [Figure 7] This figure shows the details of the joint between the upper chord member and the column of a roof structure according to another aspect of the second embodiment of the present invention. [Figure 8] This is a schematic plan view showing the arrangement of viscous dampers in a vibration damping structure according to a third embodiment of the present invention. [Figure 9] This is a schematic diagram showing a vibration damping structure according to the fourth embodiment of the present invention. [Figure 10] This figure shows the analysis results of the vibration damping structure according to the third embodiment of the present invention, and is a diagram of the story shear force coefficient of the substructure. [Figure 11] This figure shows the analysis results of the vibration damping structure according to the third embodiment of the present invention, and depicts the inter-story deformation of the roof structure. [Modes for carrying out the invention]

[0020] (First Embodiment) The vibration damping structure according to the first embodiment of the present invention will be described below with reference to the drawings. Figure 1 is a schematic diagram showing a vibration damping structure according to the first embodiment of the present invention. As shown in Figure 1, the vibration damping structure 1 according to this embodiment is used, for example, in a large-span building 10. The vibration damping structure 1 comprises a substructure 2 and a roof structure 3.

[0021] The substructure 2 is a structure to which columns, beams, etc., are installed. The substructure 2 can be made of reinforced concrete, steel, wood, etc., as appropriate.

[0022] The roof structure 3 is positioned above the substructure 2 and is supported by the substructure 2. The roof structure 3 has columns 31. In addition to the columns 31, the roof structure 3 has structural members 32 such as upper and lower chord members. The lower parts of the multiple columns 31 are connected by viscous dampers 33. The viscous dampers 33 are of a well-known configuration and are dampers that utilize viscous resistance force by filling the interior with a viscous material. The viscous dampers 33 include oil dampers.

[0023] In the roof structure 3, the stiffness of the flexible layer 31A where the columns 31 are installed is set lower than that of a typical earthquake-resistant structure, thereby creating a flexible layer. As a result, the period of the roof structure 3 is synchronized with the period of the substructure 2. The stiffness of the roof structure 3 is determined so that the period of the roof structure 3 is synchronized with the period of the substructure 2.

[0024] Figure 2 is a schematic diagram showing the phase difference of vibrations in a vibration damping structure according to the first embodiment of the present invention. As shown in Figure 2, during an earthquake, a phase difference occurs between the phase A1 of the roof structure 3 and the phase A2 of the substructure 2. By vibrating with this phase difference, the earthquake response of the substructure 2 can be reduced. Furthermore, the earthquake response of the roof structure 3 can also be reduced compared to conventional earthquake-resistant structures.

[0025] In the vibration-damping structure 1 configured in this way, the shear force on the substructure 2 can be reduced in a large-span building 10 by determining the rigidity of the layer 31A, including the columns 31 of the roof structure 3, so that the period of the roof structure 3 is synchronized with the period of the substructure 2.

[0026] (Second embodiment) Next, a vibration damping structure according to a second embodiment of the present invention will be described mainly with reference to Figures 3 to 7. In the following description of the embodiment, the same reference numerals are used for members and parts that are the same as or similar to those in the above-described embodiment, and their descriptions are omitted. A description of a configuration that differs from the embodiment will be provided.

[0027] The members of the substructure 2A and the roof-supporting members such as the columns 31 of the roof structure 3A use designated building materials as defined in Article 37, Paragraph 1 of the Building Standards Act. Designated building materials as defined in Article 37, Paragraph 1 of the Building Standards Act are general steel materials and RC (reinforced concrete) members.

[0028] Figure 3 is a schematic top view showing the roof structure of a building with a vibration-damping structure according to the second embodiment of the present invention. Figure 4 is a schematic elevation view enlarged from section IV of Figure 3. As shown in Figures 3 and 4, in a building 10A employing the vibration damping structure 1A according to this embodiment, the joint B1 between the upper end of the column 31 of the roof structure 3A and the ends of the roofing materials such as the upper chord members (horizontal members) 34 and lower chord members (horizontal members) 35 is a rotatable pin joint. This allows the natural period of the roof structure 3A to be extended. The column 31 of the roof structure 3A may be the upper part of the column 21 of the lower structure 2, or the column 31 may be connected to the upper part of the column 21.

[0029] Figure 5 shows the details of the joint B1 between the upper chord member 34 and the column 31. As shown in Figure 5, a connecting plate 41 is provided on the column 31. In the illustrated example, the column 31 is an H-shaped steel beam. However, the column 31 may also be made of other steel materials such as square steel pipes or circular steel pipes. The connecting plate 41 is joined to the flange 31a of the column 31 by welding or other means.

[0030] Figure 6 is a cross-sectional view taken along the line VI-VI in Figure 5. In the illustrated example, the upper chord member 34 is an H-shaped steel beam. However, the upper chord member 34 may also be a steel material such as a square steel pipe or a circular steel pipe. As shown in Figure 6, connecting plates 41 are positioned on both sides of the web 34b of the upper chord member 34. Bearing plates 42 are fixed to the connecting plates 41 by welding or other means.

[0031] A pin hole 43 is formed so as to penetrate the bearing plate 42, the connecting plate 41, and the web 34b in the thickness direction. A pin 44 extending in the thickness direction of the web 34b is inserted through the pin hole 43. In this way, the upper chord member 34 is connected to the column 31 so as to be rotatable around the axial direction of the pin 44.

[0032] In the large-span building 10A, by adopting member cross-sections with strong and weak axes, such as rectangular steel pipes or H-shaped steel, for the columns 21 and 31, and arranging the strong axis direction as the radial direction (direction C1 connecting the center and the outside in the plan view shown in Figure 3), the natural period can be efficiently extended without making the circumferential direction (direction C2 along the outer circumference in the plan view shown in Figure 3) a rotatable joint. However, this is not the only example; for example, it is also possible to combine this with making all or some of the circumferential beams directly above the columns 31 of the roof structure 3A pin-jointed, or with making all or some of the circumferential beams of the substructure 2A pin-jointed.

[0033] By utilizing the force flow in the large-space building 10A and employing a jointing method that allows rotation only in the radial direction (one of the two directions: radial and circumferential), the natural period is extended, resulting in significant improvements in constructability and cost.

[0034] In the vibration-damping structure 1A configured in this way, the shear force on the substructure 2A can be reduced in a large-span building 10A by determining the rigidity of the layer 31A, including the columns 31 of the roof structure 3A, so that the period of the roof structure 3A is synchronized with the period of the substructure 2A.

[0035] By pin-connecting the upper part of the column 31 of the roof structure 3A to the upper chord member 34 and lower chord member 35 of the roof structure 3A, the period of the roof structure 3A can be synchronized with the period of the lower structure 2A.

[0036] (Another embodiment of the second embodiment) Next, a vibration damping structure according to another embodiment of the second embodiment of the present invention will be described mainly with reference to Figure 7.

[0037] FIG. 7 is a view showing details of a joint portion between an upper chord member and a column of a roof structure according to another aspect of the second embodiment of the present invention. As shown in FIG. 7, a joining member 46 is provided on a flange 31a of a column 31. The joining member 46 has a pair of joining plates 41 and a joining portion 46a. The pair of joining plates 41 are arranged on both sides of a web 34b. The joining portion 46a connects upper portions of the pair of joining plates 41. The joining portion 46a is arranged at a portion 34d where an upper flange 34a of the upper chord member 34 is cut out.

[0038] Pin holes 43 are formed so as to penetrate the bearing plate 42, the joining plate 41, and the web 34b in the plate thickness direction. A pin 44 extending in the plate thickness direction of the web 34b is inserted into the pin holes 43. Thereby, the upper chord member 34 is connected to the column 31 so as to be rotatable about the axial direction of the pin 44.

[0039] In the vibration control structure 1A configured as described above, by determining the rigidity of a layer 31A including the column 31 of the roof structure 3B so as to synchronize the period of the roof structure 3B with the period of the lower structure 2A, in a building 10A with a large space, the shear force of the lower structure 2 can be reduced.

[0040] The upper portion of the column 31 of the roof structure 3B and the upper chord member 34 and the lower chord member 35 of the roof structure 3B can be pin-joined to synchronize the period of the roof structure 3B with the period of the lower structure 2A.

[0041] (Third Embodiment) Next, a vibration control structure according to the third embodiment of the present invention will be mainly described with reference to FIG. 8.

[0042] In the lower structure 2 of the vibration control structure 1, in order to maximize the TMD effect, an optimum rigidity k opt and an optimum damping c opt are represented by the following formulas (1) and (2), respectively, from Patent Document 2 (Japanese Patent Laid-Open No. 62-273374).

[0043]

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[0044] Optimal frequency ratio γ opt , optimal attenuation constant ζ opt These are calculated using the following formulas (3) and (4).

[0045]

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[0046] The primary equivalent mass of the substructure is M. B If we assume this, it can be calculated using the following equation (5).

[0047]

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[0048] Figure 10 shows the analysis results of the vibration-damping structure according to the third embodiment of the present invention, and is a diagram showing the story shear force coefficient of the substructure. Figure 11 shows the analysis results of the vibration-damping structure according to the third embodiment of the present invention, and is a diagram showing the inter-story deformation of the roof structure. Figures 10 and 11 are based on response values ​​to Level 2 seismic motion (Kobe phase as defined by the Ministry of Land, Infrastructure, Transport and Tourism) at a mass ratio μ = 0.2 and a substructure period of 0.6 seconds. In the analysis model reduced to a two-mass system, the stiffness k of the layer including the columns of the roof structure and the optimal stiffness k are shown. opt The ratio = k / k opt , the damping coefficient c of the layer including the columns of the roof structure and the optimal damping c opt Ratio = c / c opt The "story shear force coefficient" and "interstory deformation" were calculated using time-history response analysis with these parameters.

[0049] k / k opt When = 1.0, the synchronization effect maximizes the reduction in the story shear force coefficient of the substructure.

[0050] As shown in Figure 10, 0.5 ≤ k / k optWhen ≤ 2.0, k / k opt Compared to the case where the force is sufficiently small (roof seismic isolation), the story shear force coefficient of the substructure is smaller, and the synchronization effect is fully realized.

[0051] As shown in Figure 11, c / c opt The larger the value, the more the inter-story deformation of the roof structure can be reduced. On the other hand, as shown in Figure 10, the effect of reducing the story shear force coefficient of the substructure decreases. c / c opt If the value is approximately ≤5.0 or lower, the synchronization effect will be fully realized.

[0052] Therefore, k / k opt = 0.5~2.0, c / c opt It is preferable that the value is ≤ 5.0.

[0053] Figure 8 is a schematic plan view showing the arrangement of viscous dampers in a vibration damping structure according to the third embodiment of the present invention. As shown in Figure 8, viscous dampers 33 are installed in parallel with the columns 31. Viscous dampers 33 can also be arranged only in the tangential direction around the outer perimeter of the dome or arena. The illustrated example shows an example in which viscous dampers 33 are arranged in the tangential direction in an octagonal dome.

[0054] If design constraints for dynamic loads necessitate reducing the deformation of the soft layer 31A, then the optimal damping c opt By applying a damping force several times greater using a viscous damper 33 or the like, the amount of deformation of the soft layer 31A can be reduced without significantly impairing the response reduction effect. The deformation of the roof structure 3 can be kept within the range of deformation that the exterior material can follow.

[0055] In the vibration-damping structure 1 configured in this way, the shear force on the substructure 2 can be reduced in a large-span building 10 by determining the rigidity of the layer 31A, including the columns 31 of the roof structure 3, so that the period of the roof structure 3 is synchronized with the period of the substructure 2.

[0056] Also, optimal stiffness k opt and optimal damping c optIn addition to setting this, a viscous damper 33 is placed in parallel with the column 31 to synchronize the period of the roof structure 3 with the period of the substructure 2.

[0057] (Fourth embodiment) Next, a vibration damping structure according to the fourth embodiment of the present invention will be described mainly with reference to Figure 9.

[0058] As shown in Figure 9, the lower parts of the multiple columns 31 are connected by viscous dampers 33 and inertial mass dampers 38 arranged in parallel. The inertial mass damper 38 is a well-known device that converts axial deformation into rotational motion of a weight via a ball screw. The inertial mass damper 38 exerts a force proportional to the relative acceleration between two points. As a result, the load-deformation relationship becomes negative stiffness with a downward slope to the right.

[0059] In order to maximize the TMD effect, it is desirable for the flexible layer 31A, which has columns 31, to undergo large deformations in synchronization with the period of the substructure 2. However, due to design constraints against static loads, it may be difficult to reduce the stiffness of columns 31. In this case, without reducing the stiffness of columns 31, the dynamic stiffness can be reduced by arranging inertial mass dampers 38 in parallel with columns 31, thereby achieving synchronization with the substructure 2.

[0060] In the vibration-damping structure 1 configured in this way, the shear force on the substructure 2 can be reduced in a large-span building 10 by determining the rigidity of the layer 31A, including the columns 31 of the roof structure 3C, so that the period of the roof structure 3C is synchronized with the period of the substructure 2.

[0061] Furthermore, by connecting the lower part of the column 31 with a viscous damper 33 and an inertial mass damper 38 arranged in parallel, the period of the roof structure 3C can be synchronized with the period of the lower structure 2.

[0062] It should be noted that the shapes and combinations of the constituent members shown in the above-described embodiments are merely examples, and can be modified in various ways based on design requirements, etc., without departing from the spirit of the present invention.

[0063] For example, a viscoelastic damper or a steel-based damper may be installed instead of the viscous damper 33 and the inertial mass damper 38.

[0064] Furthermore, although the column 31 extends vertically, it is not limited to this; it may also extend diagonally and be formed in a V-shape with two columns.

[0065] Alternatively, the inertia mass damper 38 and a spring may be installed in series at the same location where the inertia mass damper 38 is installed. [Explanation of symbols]

[0066] 1.1A Vibration damping structure 2,2A Undercarriage 3,3A Roof structure 21,31 pillars 31A soft layer 33. Viscous damper 38. Inertial Mass Damper 44 pins k opt Optimal rigidity c opt Optimal Damping

Claims

1. Substructure and The roof structure is supported by the aforementioned substructure, A vibration control structure in which the rigidity of a layer including the columns of the roof structure is determined so that the period of the roof structure is synchronized with the period of the substructure.

2. The vibration damping structure according to claim 1, wherein the joint between the upper part of the column of the roof structure and the horizontal member of the roof structure is a pin joint.

3. Optimal stiffness k ｏｐｔ Equation (1), and optimal damping c ｏｐｔ Let this be equation (2), The vibration control structure according to claim 1, wherein viscous dampers are arranged in parallel with the columns in a layer including the columns of the roof structure. [Math 1]

4. Let k be the stiffness of the layer including the columns of the roof structure, and let c be the damping coefficient of the layer including the columns of the roof structure. k / k ｏｐｔ =0.5~2.0、 c / c ｏｐｔ The vibration damping structure according to claim 3, wherein the coefficient is ≤ 5.

0.

5. In the layer including the columns of the roof structure, the lower part of the columns is connected in parallel to a viscous damper and an inertial mass damper according to claim 1.

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