JP7094869B2 - Seismic retrofitting structure - Google Patents

Description

The present invention relates to a seismic retrofitting structure for reinforcing a building by providing seismic elements and damping mechanisms on the vertical structure surface of the building.

In Patent Document 1, stiffening braces as seismic elements are arranged on the vertical structural surface of each floor except the lowest floor of the building, and an oil damper as a damping mechanism that applies damping force to inter-story deformation is provided on the lowest floor. The seismic retrofitting structure of a building placed on a vertical structure is disclosed.
In this seismic retrofit structure, the rigidity of each floor except the lowest floor is increased by the stiffening brace as a seismic element placed on each floor except the lowest floor to suppress the interlayer deformation, and the interlayer deformation becomes larger by that amount. Since vibrations can be dampened intensively with the oil dampers on the floors, it is possible to reduce costs and efficiently reinforce buildings compared to arranging oil dampers as damping mechanisms on the vertical structure surface of each floor. ..

Japanese Unexamined Patent Publication No. 2000-087589

However, in the seismic retrofitting structure of Patent Document 1, the rigidity of each floor except the lowest floor of the building is increased by the stiffening brace, and the natural period of the building is significantly changed. Therefore, the column axial force generated at the time of an earthquake or the like becomes large, and it may be necessary to reinforce the columns.

In view of this situation, a main object of the present invention is to provide a seismic retrofitting structure capable of effectively improving the seismic performance of a building while suppressing an increase in column axial force generated at the time of an earthquake or the like as much as possible.

In the first characteristic configuration of the present invention, a seismic element with a gap that does not act on the interlayer deformation of a predetermined gap amount or less but acts on the interlayer deformation exceeding the gap amount is arranged on the vertical structural surface of the building.
A damping mechanism that applies damping force to the inter-story deformation is arranged on a vertical structure surface different from the vertical structure surface on which the seismic element with a gap is arranged.
The gapped seismic element is located on a floor where the damping mechanism is not located.
The damping mechanism is located on a floor where the gapped seismic element is not located .
The floor where the seismic element with a gap is arranged and the damping mechanism is not arranged and the floor where the damping mechanism is arranged and the seismic element with a gap is not arranged are alternately arranged for each layer of the building .

According to this configuration, by adopting a combination of a seismic element with a gap and a damping mechanism, the rigidity of the building is not increased (natural vibration cycle is changed) until a medium earthquake when the interlayer deformation of each floor is less than the gap amount. The seismic energy can be absorbed by the damping mechanism.
Then, in the event of a large earthquake in which the interlayer deformation of at least some floors exceeds the gap amount, the inter-story deformation of only some floors is prevented by the seismic element with gaps of only some floors whose interlayer deformation exceeds the gap amount. At the same time, the seismic energy can be absorbed by the damping mechanism.
Therefore, it is possible to effectively improve the seismic performance of the building while suppressing the increase in column axial force generated at the time of an earthquake as much as possible.
Further, according to this configuration, seismic elements with gaps and damping mechanisms are alternately arranged for each layer of the building, so that the behavior of the building in the vertical direction at the time of an earthquake can be easily aligned, and a part of the building in the vertical direction. It is possible to improve seismic performance more effectively while avoiding becoming a weak point in the event of an earthquake.

The plurality of seismic elements with gaps are centrally arranged on the upper side of the building.
The plurality of damping mechanisms may be centrally arranged on the lower layer side of the building.

According to this configuration, seismic elements with gaps are centrally arranged on the upper layer side of the building where the input of seismic energy does not increase so much, and multiple damping mechanisms are centrally arranged on the lower layer side of the building with high energy absorption efficiency. Seismic energy can be efficiently absorbed by the damping mechanism while suppressing the inter-story deformation of each floor on the upper layer side to less than the gap amount by the seismic element, and the seismic performance can be further improved.

The seismic element with a gap and the damping mechanism may be arranged on the same floor of the building.

According to this configuration, since the seismic element with a gap and the damping mechanism are arranged on the same floor of the building, the seismic element with a gap and the damping mechanism can be used when the influence of the higher-order mode on the building response is large. On each floor where it is placed, it is possible to enjoy both the seismic action of the seismic element with a gap and the seismic action of the damping mechanism, and the seismic performance can be further improved.

Cross-sectional view schematically showing the seismic retrofitting structure of the first embodiment Sectional view showing a seismic element with a gap Cross-sectional view schematically showing the seismic retrofitting structure of the second embodiment Cross-sectional view schematically showing the seismic retrofitting structure of the third embodiment

An embodiment of the seismic retrofitting structure of the present invention will be described with reference to the drawings.
[First Embodiment]
As shown in FIG. 1, this seismic retrofitting structure does not act on interlayer deformations having a predetermined gap amount G (see FIG. 2) or less, but acts on interlayer deformations exceeding the gap amount G. The element 10 is arranged on a plurality of floors of the building 1 on a vertical structure surface. Further, the damping mechanism 20 that applies a damping force to the interlayer deformation of the building 1 is arranged on a vertical structure surface different from the vertical structure surface on which the seismic element 10 with a gap is arranged in the building 1. The vertical structure surface of the building 1 is a vertical structure surrounded by a pair of columns 2 adjacent to each other in the left-right direction (horizontal direction in the structure surface) and a pair of beams 3 adjacent to each other in the vertical direction (vertical direction in the structure surface). It is a rectangular surface.

As shown in FIG. 1, in the damping mechanism 20, for example, a V-shaped steel frame 21 is installed on one side of vertically adjacent beams 3 on the vertical structure surface of the building 1, and the frame is the frame. A damper 22 or the like is installed between the tip of the body 21 or the like and the pillar 2. The damper 22 includes a speed-dependent oil damper and a viscous damper that apply a damping force to the deformation speed in the interlayer deformation of the building 1, and a displacement-dependent history damper that applies a damping force to the displacement in the interlayer deformation of the building 1. Various things such as lead dampers) can be used as appropriate.

The details of the seismic element 10 with a gap will be described later, but for example, one end side of a brace material 11 made of steel or the like diagonally arranged on the vertical structure surface of the building 1 is left and right within a predetermined range corresponding to the gap amount G. It can be mounted and configured so that it can move freely in the direction.

In this way, by combining the seismic element 10 with a gap and the damping mechanism 20, the rigidity of the building 1 is increased until a medium earthquake in which the interlayer deformation of each floor of the building 1 is less than the gap amount G (see FIG. 2). Seismic energy can be absorbed by the damping mechanism 20 in the absence (state in which the natural period is not changed). Then, in the event of a large earthquake in which the inter-story deformation of at least some floors exceeds the gap amount G, the seismic element 10 with a gap is applied only to some floors in which the inter-story deformation exceeds the gap amount G, and only some of the floors are affected. By preventing the inter-story deformation of the above, the seismic energy can be absorbed by the damping mechanism 20 while suppressing the increase in the column axial force generated in the column 2 as much as possible.
Therefore, it is possible to effectively improve the seismic performance of the building 1 while suppressing the increase in the column axial force generated at the time of an earthquake or the like as much as possible.

The building 1 to be retrofitted may be either an existing building or a new building, but as described above, this seismic retrofitting structure suppresses the increase in column axial force generated during an earthquake or the like as much as possible. Since the seismic energy can be absorbed by the damping mechanism 20, it is suitably used for a seismic retrofitting method in which a seismic element 10 with a gap and a damping mechanism 20 are additionally arranged for the existing building to retrofit the existing building. be able to.

In this first embodiment, as shown in FIG. 1, seismic elements 10 with gaps are centrally arranged on the upper layer side 1A of the building 1 where the input of seismic energy does not increase so much, and the lower layer side 1B of the building 1 having high energy absorption efficiency. The damping mechanism 20 is centrally arranged in the. In the illustrated example, two (multiple examples) seismic elements 10 with gaps are arranged on each floor of the eighth floor or higher as the upper floor side 1A of the building 1, and two seismic elements 10 with gaps are arranged on each floor of the seventh floor or lower as the lower floor side 1B of the building 1 (plural examples). The damping mechanism 20 of a plurality of examples) is arranged, the number of floors of the upper layer side 1A is larger than the number of floors of the lower layer side 1B, and the number of seismic elements 10 with a gap is larger than that of the damping mechanism 20. Incidentally, conversely, the number of damping mechanisms 20 may be larger than that of the seismic elements 10 with gaps, and the number of damping mechanisms 20 and the seismic elements 10 with gaps may be the same.
With such a configuration, the seismic element 10 with a gap can efficiently absorb the seismic energy by the damping mechanism 20 while suppressing the interlayer deformation of each floor of the upper layer side 1A to the gap amount G or less, and the seismic performance is further effective. Can be enhanced.

In the illustrated example, the seismic element 10 with a gap and the damping mechanism 20 are arranged at the same position in the left-right direction of the building 1 at intervals in the left-right direction on each floor. The arrangement of the damping mechanism 20 on each floor can be changed as appropriate.
For example, the seismic element 10 with a gap and the damping mechanism 20 may be arranged on each floor so as to be located at different positions in the left-right direction of the building 1 between the vertically adjacent floors, or are adjacent to each other in the left-right direction. May be arranged.
Further, the number of installed seismic elements 10 with gaps and damping mechanism 20 on each floor can be appropriately changed, and the number of installed seismic elements 10 with gaps and damping mechanism 20 in the entire building 1 can also be appropriately changed.
Further, for example, the beams on a part of the lower floor 1B where the damping mechanism 20 is arranged are removed to facilitate the inter-story deformation in the event of an earthquake or the like, and the damping capacity of the floor on which the inter-story deformation is likely to occur is higher than the others. A large damping mechanism 20 may be arranged.

Next, a specific configuration of the seismic element 10 with a gap will be described.
The configuration of the seismic element 10 with a gap described below is just an example, and an appropriate configuration can be adopted according to various circumstances such as the condition of the building 1 to be retrofitted and the level of seismic retrofitting. ..

As shown in FIG. 2, in order to form the seismic element 10 with a gap, the vertical structure side of the upper and lower middle portions of each pillar 2 constituting the vertical structure surface of the building 1 and the left and right middle portions of each beam 3 are formed. A steel mounting portion 13 having a circular insertion hole (not shown) for mounting the brace material 11 with a gap with a connecting bolt 12 is formed on each of the vertical structure side so as to project.
Then, both ends of the four brace members 11 are attached to the attachment portion 13 with connecting bolts 12 and nuts (not shown) while straddling the joint portions 4 at the four corners of the vertical structure surface of the building 1.
Therefore, in the event of an earthquake or the like, it is possible to reinforce the vertical structural surface of the building 1 while avoiding the addition of stress due to the brace material 11 with a gap to the joint portion 4 where stress concentration is likely to occur in the first place.

At the lower end of each brace material 11, a circular bolt hole 11a having a hole diameter corresponding to the bolt diameter of the connecting bolt 12 is formed, and the connecting bolt 12 and the nut are attached around the axis orthogonal to the vertical structure surface. It is rotatably connected to the portion 13.
At the upper end of each brace material 11, a long hole 11b is formed which allows the connecting bolt 12 to move in the left-right direction within a predetermined range corresponding to the gap amount G along the left-right direction. The upper end of each brace material 11 is rotatably connected to the mounting portion 13 by a connecting bolt 12 and a nut so as to be movable in the left-right direction within a predetermined range and around an axis orthogonal to the vertical structural surface.

Therefore, in the seismic element 10 with a gap, when the interlayer deformation of the floor on which the element is placed is less than or equal to the gap amount G, the connecting bolt 12 at the upper end of each brace material 11 has a gap along the elongated hole 11b. By moving in the left-right direction within a predetermined range corresponding to the amount G, it is possible to appropriately tolerate interlaminar deformation without exerting the brace effect.
On the other hand, in the seismic element 10 with a gap, when the interlayer deformation of the floor on which the element is placed exceeds the gap amount G, the connecting bolt 12 at the upper end of each brace material 11 is the left-right end of the elongated hole 11b. By contacting and pressing the portion, the brace effect can be exerted and the interlayer deformation can be appropriately prevented.

[Second Embodiment]
FIG. 3 shows the seismic retrofitting structure of the second embodiment. The seismic retrofitting structure of the second embodiment is another embodiment of the arrangement pattern of the seismic element 10 with a gap and the damping mechanism 20.
In the seismic retrofitting structure of the second embodiment, the seismic elements 10 with gaps and the damping mechanism 20 are alternately arranged for each layer of the building 1. In the illustrated example, two (plural examples) damping mechanisms 20 are arranged on the odd floor 1C of the building 1, and two (plural examples) seismic elements 10 with gaps are arranged on the even floor 1D of the building 1. ..
Therefore, the behavior of the building 1 in the vertical direction at the time of an earthquake or the like can be easily aligned, and the seismic performance can be effectively improved while avoiding that a part of the building 1 in the vertical direction becomes a weak point.
Contrary to the above configuration, the seismic element 10 with a gap may be arranged on the odd-numbered floor 1C of the building 1, and the damping mechanism 20 may be arranged on the even-numbered floor 1D of the building 1. Further, the number of installed seismic elements 10 with gaps and damping mechanism 20 on each floor can be appropriately changed, and the number of installed seismic elements 10 with gaps and damping mechanism 20 in the entire building 1 can also be appropriately changed.
Since the other configurations are the same as the configurations described in the first embodiment, the same numbers are added to the same configuration parts, and the description thereof will be omitted.

[Third Embodiment]
FIG. 4 shows the seismic retrofitting structure of the third embodiment. The seismic retrofitting structure of the third embodiment is also another embodiment of the arrangement pattern of the seismic element 10 with a gap and the damping mechanism 20.
In the seismic retrofitting structure of the third embodiment, the seismic element 10 with a gap and the damping mechanism 20 are arranged on the same floor of the building 1. In the illustrated example, one seismic element 10 with a gap and one damping mechanism 20 are arranged on different vertical structural surfaces in the left-right direction on each floor of the building 1.
Therefore, when the influence of the higher-order mode on the building response is large, the seismic action by the seismic element 10 with a gap and the damping mechanism 20 are applied to each floor of the building 1 where the seismic element 10 with a gap and the damping mechanism 20 are arranged. Both of the seismic action can be enjoyed, and the seismic performance can be further effectively improved.
The number of installed seismic elements 10 with gaps and damping mechanism 20 on each floor can be appropriately changed to a plurality of each or to a number other than the same number, which is different from each other. Further, the number of installed seismic elements 10 with gaps and damping mechanism 20 in the entire building 1 can be changed as appropriate.
Since the other configurations are the same as the configurations described in the first embodiment, the same numbers are added to the same configuration parts, and the description thereof will be omitted.

[Another Embodiment]
Other embodiments of the present invention will be described. The configurations of each embodiment described below are not limited to being applied independently, but can also be applied in combination with the configurations of other embodiments.

(1) In the above-described embodiment, the case where the seismic element 10 with a gap and the damping mechanism 20 are arranged on each floor of the building 1 is shown as an example. A seismic element 10 with a gap or a damping mechanism 20 may be arranged on a part of the floor in the direction.

(2) The specific configuration and arrangement of the seismic element 10 with a gap and the damping mechanism 20 are not limited to the configuration and arrangement shown in the above-described embodiment, and various configurations and arrangements can be appropriately adopted. ..

1 Building 10 Seismic element with gap 20 Damping mechanism B Building

Claims (1)

Seismic elements with gaps that do not act on inter-story deformation below a predetermined gap but act on inter-story deformation exceeding the gap amount are arranged on the vertical structural surface of the building.
A damping mechanism that applies damping force to the inter-story deformation is arranged on a vertical structure surface different from the vertical structure surface on which the seismic element with a gap is arranged.
The gapped seismic element is located on a floor where the damping mechanism is not located.
The damping mechanism is located on a floor where the gapped seismic element is not located .
The floor where the seismic element with a gap is arranged and the damping mechanism is not arranged and the floor where the damping mechanism is arranged and the seismic element with a gap is not arranged are alternately arranged for each layer of the building. structure.

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