JP7791045B2 - Vibration-damping structure - Google Patents

Description

The present invention relates to a vibration control structure.

Buildings with stepped floors and stepped spectator seating are known, such as stadiums, halls, and arenas where various sports and events are held (see, for example, Patent Document 1). In such buildings, diagonal beams (raker beams) are installed at a specified span, and the stepped floors are installed along the diagonal beams.

Patent No. 6833332

In buildings with diagonal beams, the beams function as seismic braces, which can cause the rigidity of the frame to be excessively high or the rigidity of the entire building to become unbalanced. This can increase the shear response during an earthquake and the maximum story drift angle response of floors without diagonal beams.

The present invention therefore aims to provide a vibration control structure that can improve the vibration control performance of buildings equipped with diagonal beams.

To achieve the above objective, the system comprises a column-beam frame having multiple stories and equipped with horizontal beams and columns; low-rigidity diagonal beams provided between some of the stories, with their axial direction oblique to the horizontal, and with their lower ends joined to the column-beam frame in the story below the stories and their upper ends joined to the column-beam frame in the story above the stories; and a vibration control device provided between the stories on which the low-rigidity diagonal beams are provided, with one of the lower and upper ends of the low-rigidity diagonal beams joined to the column-beam frame via either a sliding bearing or a rolling bearing so as to be movable relative to the column-beam frame in the horizontal direction, and the other end joined to the column-beam frame via either a rigid joint or a pin joint.

In this invention, the low-rigidity diagonal beams can be configured so that one end is capable of horizontally deforming relative to the beam-column frame, thereby not bearing seismic forces. Therefore, even when installing multiple diagonal beams in a building to provide stepped floors for spectators, by using low-rigidity diagonal beams for at least some of the beams, it is possible to prevent the installation of multiple diagonal beams from making the building excessively rigid. Deformation is concentrated between the stories where low-rigidity diagonal beams are installed, but by installing vibration control devices between these stories, it is possible to efficiently absorb the seismic energy between the stories and reduce response during an earthquake. As a result, the vibration control performance of buildings equipped with diagonal beams can be improved.

The vibration-damping structure of the present invention may also include a damper that reduces the relative displacement between the one end of the low-rigidity diagonal beam and the beam-column structure when the inter-story deformation angle between the stories where the low-rigidity diagonal beam is provided exceeds a predetermined value.

With this configuration, if the inter-story deformation angle between the stories where the low-rigidity diagonal beams are installed exceeds a predetermined value due to earthquake motion that exceeds expectations, the damper will limit the relative horizontal displacement between one end of the low-rigidity diagonal beam and the column-beam frame, allowing the damper and low-rigidity diagonal beam to bear the horizontal force of the earthquake motion and absorb the seismic energy.

In the vibration-damping structure of the present invention, the damper may be configured to reduce only the relative displacement in the axial direction of the low-rigidity diagonal beam and in the direction in which the one end of the low-rigidity diagonal beam moves away from the beam-column frame when the inter-story deformation angle exceeds a predetermined value.

With this configuration, when the inter-story deformation angle exceeds a predetermined value, the relative displacement in the axial direction of the low-rigidity diagonal beam and in the direction away from one end of the low-rigidity diagonal beam and the column-beam frame is limited, so that the damper and the low-rigidity diagonal beam can bear the tensile force acting on the low-rigidity diagonal beam.
When the damper reduces the relative displacement of one end of the low-rigidity diagonal beam in the direction toward the column-beam frame and limits the relative displacement of one end of the low-rigidity diagonal beam in the direction toward the column-beam frame, the damper and the low-rigidity diagonal beam bear the compressive force acting on the low-rigidity diagonal beam. In such a case, a force acts on the low-rigidity diagonal beam in the direction of lifting it from the column-beam frame. In this invention, as described above, when the story deformation angle exceeds a predetermined value, the low-rigidity diagonal beam bears only the tensile force, preventing the low-rigidity diagonal beam from lifting up from the column-beam frame. This ensures the safety of facilities and equipment above the low-rigidity diagonal beam, such as spectator seats installed on the step floor above the low-rigidity diagonal beam.

In the vibration control structure of the present invention, the damper may be a steel damper extending in the same direction as the axial direction of the low-rigidity diagonal beam and provided between the one end of the low-rigidity diagonal beam and the column-beam frame, the steel damper and the column-beam frame being pin-connected, and the steel damper and the one end of the low-rigidity diagonal beam may be connected in such a way that, when the inter-story deformation angle is equal to or less than a predetermined value, relative displacement in the axial direction of the low-rigidity diagonal beam is permitted, and when the inter-story deformation angle exceeds the predetermined value, relative displacement in the axial direction of the low-rigidity diagonal beam in a direction in which the one end of the low-rigidity diagonal beam and the column-beam frame move closer together is permitted, and relative displacement in the axial direction of the low-rigidity diagonal beam in a direction in which the one end of the low-rigidity diagonal beam and the column-beam frame move apart is restricted.

This configuration makes it easy to realize a mechanism in which the damper and low-rigidity diagonal beams absorb the tensile force acting on the low-rigidity diagonal beams when the inter-story deformation angle exceeds a predetermined value.

In the vibration-damping structure of the present invention, the predetermined value of the inter-story deformation angle may be 1/100 rad.

With this configuration, the damper does not act in earthquake motions of level 2 or below, but acts in earthquake motions above level 2, allowing the low-rigidity diagonal beams and damper to absorb earthquake energy.

In the vibration control structure of the present invention, a stepped floor for spectator seating may be provided on top of the low-rigidity diagonal beams.

This configuration can improve the vibration control performance of buildings that have stepped floors for spectator seating, etc.

This invention can improve the vibration control performance of buildings equipped with diagonal beams.

1 is a vertical cross-sectional view showing a vibration damping structure according to a first embodiment. FIG. 10 is a vertical cross-sectional view showing a vibration damping structure according to a second embodiment. FIG. 10 is a vertical cross-sectional view showing a vibration damping structure according to a modified example of the embodiment.

(First embodiment)
A vibration damping structure according to a first embodiment of the present invention will now be described with reference to FIG.
The vibration control structure 1 according to this embodiment shown in Figure 1 is employed in a building 11 equipped with stepped spectator seating 12, such as a stadium, hall, or arena. The building 11 has multiple floors (layers), and spectator seating is provided on multiple floors. In this embodiment, the building 11 has four floors. In Figure 1, the first to fourth floors are designated by reference numerals 111 to 114 in order. Reference numeral 14 in Figure 1 denotes a roof.
The vibration control structure 1 has a column-beam frame 2 equipped with horizontal beams 21 and columns 22, a low-rigidity diagonal beam 3 provided on the first floor, a sliding support 4 provided between the low-rigidity diagonal beam 3 and the column-beam frame 2, and a vibration control device 5 provided on the first floor.

The column-beam structure 2 is a structure constructed of horizontal beams 21 and columns 22 across the entire first to fourth floors of the building 11. The column-beam structure 2 is supported by the ground.

The axis of the low-rigidity diagonal beam 3 extends in a diagonal direction that is oblique to the horizontal. The diagonal direction in which the axis of the low-rigidity diagonal beam 3 extends is from the center of the building 11 (left side of Figure 1) to the outer periphery (right side of Figure 1), from the bottom to the top. The direction in which the axis of the low-rigidity diagonal beam 3 extends is referred to as the axial direction.

The lower end 31 (one end) of the low-rigidity diagonal beam 3 is connected to the horizontal beam 211 on the first floor via a sliding bearing 4. The lower end 31 of the low-rigidity diagonal beam 3 and the horizontal beam 211 on the first floor are capable of relative horizontal displacement. The upper end 32 (the other end) of the low-rigidity diagonal beam 3 is connected to the joint 23 between the horizontal beam 212 on the second floor and the column 22 by either a rigid joint or a pin joint. The relative horizontal and vertical displacement of the upper end 32 of the low-rigidity diagonal beam 3 and the joint 23 between the horizontal beam 212 on the second floor and the column 22 is constrained. The horizontal beam 211 on the first floor refers to the horizontal beam 21 that supports the floor of the first floor, and the horizontal beam 212 on the second floor refers to the horizontal beam 21 that supports the floor of the second floor.
The vibration control device 5 is installed in a wall shape between the horizontal beam 216 on the first floor and the horizontal beam 212 on the second floor using an oil damper or the like. In Fig. 1, the horizontal beam 216 on the first floor, which is located below the vibration control device 5 and to which the vibration control device 5 is connected, is installed at a position slightly lower than the horizontal beam 211 on the first floor to which the lower end portion 31 of the low-rigidity diagonal beam 3 is joined via the sliding bearing 4. Note that the height relationship between the horizontal beam 216 on the first floor to which the vibration control device 5 is connected and the other horizontal beams 211 on the first floor may be other than that described above.

A stepped floor 13 is provided on top of the low-rigidity diagonal beams 3, and stepped spectator seats 12 are provided on top of that. In this embodiment, spectator seats 12 are also provided on the stepped floor 13 above the diagonal beams 6 on the fourth floor. The diagonal beams 6 on the fourth floor also extend obliquely from the center of the building 11 to the periphery, from bottom to top.
The diagonal beams 6 on the fourth floor are rigidly connected to the column and beam frame 2 at both their upper and lower ends, and their relative displacement in the horizontal and vertical directions relative to the column and beam frame 2 is restrained.

Next, the operation and effect of the vibration damping structure according to the first embodiment will be described.
In the vibration-damping structure of this embodiment, the low-rigidity diagonal beams 3 are configured so that their lower ends 31 are horizontally deformable relative to the column-beam frame, thereby preventing them from bearing seismic forces. Therefore, even if a building 11 has many diagonal beams, using at least some of the diagonal beams as low-rigidity diagonal beams 3 can prevent the building 11 from becoming excessively rigid due to the large number of diagonal beams. Deformation due to earthquake motion is concentrated between the stories where the low-rigidity diagonal beams 3 are installed. However, by installing vibration-damping devices 5 between these stories, the vibration-damping devices 5 can efficiently absorb seismic energy and reduce earthquake response. As a result, the vibration-damping performance of the building 11 equipped with diagonal beams can be improved. This embodiment improves the vibration-damping performance of the building 11, which has step floors 13 for accommodating spectator seats 12, ensuring the safety of the spectator seats 12.

Second Embodiment
Next, a second embodiment will be described. The same or similar members and parts as those in the first embodiment will be designated by the same reference numerals, and the description thereof will be omitted. Only the configurations different from the first embodiment will be described.
As shown in Figure 2, in the vibration-control structure 1B according to the second embodiment, a damper 7 is provided between the lower side of the low-rigidity diagonal beam 3 and the horizontal beam 211 on the first floor. When the inter-story deformation angle between the stories (first floor portion) where the low-rigidity diagonal beam 3 is provided exceeds a predetermined value, the damper 7 reduces the relative displacement between the lower end 31 of the low-rigidity diagonal beam 3 and the horizontal beam 211 on the first floor. In this embodiment, the predetermined value of the inter-story deformation angle is set to 1/100 rad. Furthermore, the damper 7 in this embodiment is configured to reduce only the relative displacement in the axial direction of the low-rigidity diagonal beam 3 and in the direction in which the lower end 31 of the low-rigidity diagonal beam 3 moves away from the horizontal beam 211 on the first floor when the inter-story deformation angle exceeds the predetermined value.

Damper 7 is a steel damper. Damper 7 has a tension rod 71 and a gap device 72. Gap device 72 is a device that applies force to tension rod 71 when the inter-story deformation angle exceeds a predetermined value.

One axial end 711 of the tension rod 71 is pin-connected to the horizontal beam 211 on the first floor near the lower end 31 of the low-rigidity diagonal beam 3. The other axial end 712 of the tension rod 71 is connected to the axial middle of the low-rigidity diagonal beam 3 via a gap device 72. The axial direction of the tension rod 71 and the axial direction of the low-rigidity diagonal beam 3 are parallel.

The gap device 72 has a cylindrical portion 721 , a fixing portion 722 , and a diameter expanding member 723 .
The cylindrical portion 721 is disposed coaxially with the tension rod 71, and the other end 712 of the tension rod 71 is inserted through the cylindrical portion 721. The tension rod 71 inserted through the cylindrical portion 721 and the cylindrical portion 721 are capable of relative displacement in the axial direction.
The cylindrical portion 721 is fixed to the axially intermediate portion of the low-rigidity diagonal beam 3. The cylindrical portion 721 is fixed in parallel to the low-rigidity diagonal beam 3.
The diameter expanding member 723 is attached near the other end 712 of the tension rod 71. Its diameter is larger than the inner diameter of the cylindrical portion 721 and cannot pass through the cylindrical portion 721. The diameter expanding member 723 is located on the other axial side of the tension rod 71 relative to the cylindrical portion 721 that is inserted through the tension rod 71. When the tension rod 71 moves to one axial side relative to the cylindrical portion 721 and the diameter expanding member 723 comes into contact with the end face on the other axial side of the cylindrical portion 721, it becomes impossible for the tension rod 71 to move further to one axial side relative to the cylindrical portion 721.

In the initial state when the damper 7 is installed, the other axial side of the tension rod 71 protrudes further axially than the cylindrical portion 721, and the cylindrical portion 721 and the expansion member 723 are spaced apart. The distance between the cylindrical portion 721 and the expansion member 723 is set so that, due to seismic activity, the low-rigidity diagonal beam 3 and the first-floor horizontal beam 211 are displaced relative to each other so that the lower end 31 of the low-rigidity diagonal beam 3 moves toward the outside of the building 11 (to the right in Figure 2) relative to the first-floor horizontal beam 211, and the inter-story deformation angle of the first floor portion of the building 11 reaches a predetermined value, causing the cylindrical portion 721 and the expansion member 723 to come into contact.

As a result, when the story deformation angle of the first floor of the building 11 exceeds a predetermined value, the relative displacement in the above-mentioned direction between the low-rigidity diagonal beams 3 and the first-floor horizontal beams 211 is constrained. This direction refers to the direction in which the lower ends 31 of the low-rigidity diagonal beams 3 face outward from the building 11 relative to the first-floor horizontal beams 211. Once the relative displacement in the above-mentioned direction between the low-rigidity diagonal beams 3 and the first-floor horizontal beams 211 is constrained, any further relative displacement between the low-rigidity diagonal beams 3 and the first-floor horizontal beams 211 in the above-mentioned direction will cause a tensile force to act on the tension rods 71, which in turn will also act on the low-rigidity diagonal beams 3. In other words, when the story deformation angle exceeds a predetermined value, the dampers 7 and the low-rigidity diagonal beams 3 can bear the tensile force acting on the low-rigidity diagonal beams 3 due to seismic motion.
The tension rod 71 has its lower end pin-jointed to the horizontal beam 211 on the first floor and its upper end inserted into a cylindrical section 721 parallel to the low-rigidity diagonal beam 3, so that it remains parallel to the low-rigidity diagonal beam 3 even if the low-rigidity diagonal beam 3 and the horizontal beam 211 on the first floor are displaced relative to each other.

One end 711 of the tension rod 71 and the tubular portion 721 are sufficiently separated so that even if seismic motion causes a relative displacement between the low-rigidity diagonal beam 3 and the horizontal beam 211 on the first floor, such that the lower end 31 of the low-rigidity diagonal beam 3 moves in a direction toward the inside of the building 11 (to the left in Figure 2) relative to the horizontal beam 211 on the first floor, the tubular portion 721 does not reach one end 711 of the tension rod 71.
As a result, even if seismic motion causes a relative displacement between the low-rigidity diagonal beam 3 and the horizontal beam 211 on the first floor, such that the lower end 31 of the low-rigidity diagonal beam 3 moves in a direction toward the inside of the building 11 relative to the horizontal beam 211 on the first floor, the seismic motion does not act on the damper 7, and the seismic motion does not act on the low-rigidity diagonal beam 3 either.
If the lower end 31 of the low-rigidity diagonal beam 3 is fixed to the horizontal beam 211 on the first floor, relative displacement of the lower end 31 of the low-rigidity diagonal beam 3 relative to the horizontal beam 211 on the first floor in a direction toward the inside of the building 11 will result in a compressive force acting on the low-rigidity diagonal beam 3. In this embodiment, the lower end 31 of the low-rigidity diagonal beam 3 is not fixed to the horizontal beam 211 on the first floor, and even if seismic motion causes a relative displacement between the low-rigidity diagonal beam 3 and the horizontal beam 211 on the first floor in which the lower end 31 of the low-rigidity diagonal beam 3 moves in a direction toward the inside of the building 11 relative to the horizontal beam 211 on the first floor, the seismic motion does not act on the damper 7, and therefore no compressive force acts on the low-rigidity diagonal beam 3.

In the vibration-control structure 1B according to the second embodiment described above, if the inter-story deformation angle between stories where low-rigidity diagonal beams 3 are installed exceeds a predetermined value due to earthquake motion that exceeds expectations, the dampers 7 limit the relative horizontal displacement between the low-rigidity diagonal beams 3 and the horizontal beams 211 on the first floor, allowing the dampers 7 and low-rigidity diagonal beams 3 to bear the horizontal force of the earthquake motion and absorb the seismic energy.

In addition, in the vibration control structure 1B according to the second embodiment, when the inter-story deformation angle exceeds a predetermined value, the damper 7 and the low-rigidity diagonal beam 3 are configured to bear only the tensile force acting on the low-rigidity diagonal beam 3 due to seismic motion, and not to bear the compressive force acting on the low-rigidity diagonal beam 3 due to seismic motion.
If the dampers 7 and low-rigidity diagonal beams 3 are set to bear the compressive force acting on the low-rigidity diagonal beams 3, a force acts on the low-rigidity diagonal beams 3 in a direction that causes them to lift up from the beam-column frame 2. In the second embodiment, as described above, when the story deformation angle exceeds a predetermined value, the low-rigidity diagonal beams 3 bear only the tensile force, preventing the low-rigidity diagonal beams 3 from lifting up from the beam-column frame 2. This ensures the safety of the spectator seats 12 provided on the step floor 13 above the low-rigidity diagonal beams 3.

In the vibration-damping structure 1B according to the second embodiment, the predetermined value of the inter-story deformation angle is set to 1/100 rad.
As a result, the dampers 7 do not act in earthquake motions of level 2 or less, but act in earthquake motions above level 2, allowing the low-rigidity diagonal beams 3 and the dampers 7 to absorb earthquake energy. In addition, the response deformation can be reduced to 1/80 rad or less, which is repairable.

Although the embodiment of the vibration damping structure according to the present invention has been described above, the present invention is not limited to the above embodiment and can be modified as appropriate within the scope of the invention.
For example, in the above embodiment, a sliding bearing 4 is provided between the lower end 31 of the low-rigidity diagonal beam 3 and the column-beam frame 2, but a rolling bearing may be provided instead of the sliding bearing 4, and the lower end 31 of the low-rigidity diagonal beam 3 may be joined to the column-beam frame 2 via the rolling bearing so that it can move horizontally relative to the column-beam frame 2.
In the above embodiment, the upper end 32 of the low-rigidity diagonal beam 3 is joined to the joint 23 between the horizontal beam 212 on the second floor and the column 22 by either a rigid joint or a pin joint, but the part of the column-beam structure 2 to which the upper end 32 of the low-rigidity diagonal beam 3 is joined may be other than the joint 23 between the horizontal beam 21 and the column 22.
In the above embodiment, the lower end portions 31 of the low-rigidity diagonal beams 3 are joined to the column-beam frame 2 via sliding bearings 4 so as to be relatively movable in the horizontal direction, and the upper end portions 32 of the low-rigidity diagonal beams 3 are joined to the column-beam frame 2 by either a rigid joint or a pin joint. Alternatively, the upper end portions 32 of the low-rigidity diagonal beams 3 may be joined to the column-beam frame 2 via either sliding bearings 4 or rolling bearings so as to be relatively movable in the horizontal direction, and the lower end portions 31 of the low-rigidity diagonal beams 3 may be joined to the column-beam frame 2 by either a rigid joint or a pin joint.

In the above embodiment, the vibration damping device 5 provided on the beam-column frame 2 is provided in a wall shape, but it may also be provided in a brace shape, like a vibration damping device 5C shown in FIG.
In the above embodiment, the low-rigidity diagonal beams 3 are provided on the first floor, but they may also be provided on floors other than the first floor, or on multiple floors excluding all floors.
In order to concentrate deformation due to earthquake motion more between the stories where the low-rigidity diagonal beams 3 are provided, braces or the like may be provided between the stories where the low-rigidity diagonal beams 3 are provided to increase the rigidity between the stories.

In the second embodiment described above, when the inter-story deformation angle exceeds a predetermined value, the damper 7 and the low-rigidity diagonal beam 3 are configured to bear only the tensile force acting on the low-rigidity diagonal beam 3 due to seismic motion, and not to bear the compressive force acting on the low-rigidity diagonal beam 3 due to seismic motion, but they may also be configured to bear the compressive force.
In the second embodiment, the predetermined value of the inter-story deformation angle is set to 1/100 rad, but it may be set to any value.

The Sustainable Development Goals (SDGs) are one of the 17 international goals adopted at the United Nations Summit in September 2015. The vibration control structure of this embodiment can contribute to achieving one of the 17 SDGs, for example, goal 11: "Sustainable cities and communities."

1, 1B Vibration control structure 2 Column and beam frame 3 Low-rigidity diagonal beam 4 Sliding bearing 5, 5C Vibration control device 6 Diagonal beam 12 Spectator seats 13 Step floor 21, 211, 212, 216 Horizontal beam 22 Column 31 Lower end (one end)
32 Upper end (other end)

Claims (6)

a beam-column frame having a plurality of stories and including horizontal beams and columns;
a low-rigidity diagonal beam provided between some of the layers, with an axial direction oblique to the horizontal direction, with a lower end joined to the column-beam frame in a lower layer between the layers and an upper end joined to the column-beam frame in an upper layer between the layers;
a vibration damping device provided between the layers where the low-rigidity diagonal beams are provided,
The low-rigidity diagonal beam has a vibration-damping structure in which one of its lower and upper ends is connected to the column-beam frame via either a sliding bearing or a rolling bearing so that it can move horizontally relative to the column-beam frame, and the other end is connected to the column-beam frame via either a rigid joint or a pin joint. The vibration control structure described in claim 1, further comprising a damper that reduces the relative displacement between the one end of the low-rigidity diagonal beam and the beam-column structure when the inter-story deformation angle between the stories where the low-rigidity diagonal beam is provided exceeds a predetermined value. A vibration control structure as described in claim 2, wherein the damper reduces only the relative displacement in the axial direction of the low-rigidity diagonal beam and in the direction separating the one end of the low-rigidity diagonal beam from the beam-column frame when the inter-story deformation angle exceeds a predetermined value. the damper is a steel damper extending in the same direction as the axial direction of the low-rigidity diagonal beam and provided between the one end side of the low-rigidity diagonal beam and the beam-column frame,
The steel damper and the column-beam frame are connected by pins,
4. The vibration control structure according to claim 3, wherein the steel damper and the one end of the low-rigidity diagonal beam are joined so as to permit relative displacement in the axial direction of the low-rigidity diagonal beam when the inter-layer deformation angle is equal to or less than a predetermined value, permit relative displacement in the axial direction of the low-rigidity diagonal beam in a direction in which the one end of the low-rigidity diagonal beam approaches the column-beam frame when the inter-layer deformation angle exceeds the predetermined value, and restrict relative displacement in the axial direction of the low-rigidity diagonal beam in a direction in which the one end of the low-rigidity diagonal beam moves away from the column-beam frame. The vibration control structure described in claim 2, wherein the predetermined value of the inter-story deformation angle is 1/100 rad. The vibration control structure of claim 1, wherein a stepped floor for providing spectator seating is provided on top of the low-rigidity diagonal beams.