JP3477597B2 - Seismic retrofit structure of existing building - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a reinforcing structure for improving seismic resistance of an existing building.

[0002]

2. Description of the Related Art In recent years, buildings have been required to have a higher level of earthquake resistance, and newly constructed buildings have to be given greater consideration to earthquake resistance than ever before. It is natural that However, even if existing buildings that were constructed in the past and are still used today are considered to have sufficient seismic resistance at the time of construction, seismic resistance is a problem at this time. Therefore, it is necessary to reinforce such existing buildings to improve their seismic resistance.

Many existing buildings having a relatively old building age have high horizontal rigidity but do not have sufficient bearing capacity. Therefore, in order to improve the earthquake resistance of such existing buildings, the toughness is increased. It is conceivable to increase the allowable deformation amount by increasing the permissible deformation amount, or to install a reinforcing element such as a seismic wall or brace in a key place to increase the proof stress. However, increasing the toughness of the existing building requires remarkably large-scale renovation work and is almost difficult. Therefore, in reality, the seismic wall is installed inside the existing building to increase the bearing capacity. The method is generally taken.

[0004]

However, although it is technically relatively easy to provide seismic resistant walls and braces inside existing structures, their installable positions are large in a plan plan. In many cases, the seismic wall or brace cannot be freely installed at a required position due to restrictions, and the convenience of use is significantly impaired. Therefore, in many cases, a desired reinforcing effect cannot be obtained by such a method, and an effective measure has been desired.

The present invention has been made in view of the above circumstances, and an object thereof is to improve the earthquake resistance of existing buildings.

[0006]

Retrofit structure of an existing building according to claim 1 Means for Solving the Problems] is a reinforcing structure for improving the earthquake resistance of existing buildings, form the interior of the existing building
The floor of a number of rectangular compartments made up and separated by pillar beams
In the space that has been removed, a frame with a different natural period from this existing building is erected on the foundation of the existing building with a space between it and the existing structure, and between the frame and the existing building. It is characterized in that a damper is inserted.

The seismic retrofit structure for an existing building described in claim 2 has a seismic isolation device between the frame and the foundation of the existing building in the seismic retrofit structure for an existing building according to claim 1. It is characterized by being arranged.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of an earthquake-proof reinforcing structure for an existing building according to the present invention will be described with reference to FIGS. 1 and 2. The existing building 1 shown in FIG. 1 is a reinforced concrete structure constructed on the ground G, and the existing building 1
The foundation 1a of is in a state of being buried in the ground G.

The floor of each floor of the existing building 1 is divided into a plurality of rectangular sections by pillars and beams 1b, and the floors of the sections located at the four corners of the existing building 1 among the sections are the pillars and beams 1b around them. It is removed and left, so that the spaces 2 penetrating from the foundation 1a to the roof are formed at the four corners of the existing building 1.

In this space 2, a frame 10 extending upward along the space 2 is erected on a foundation 1a. The frame 10 is a steel frame structure having high strength and relatively low horizontal rigidity, whereby the natural period of the frame 10 against earthquake motion is set longer than the natural period of the existing building 1 made of reinforced concrete. There is. At this time, regarding the determination of the natural period of the frame 10, it is assumed that the vibration property of the existing building 1 is evaluated and the natural period that is most easily coupled to the vibration characteristic is designed.

The roof portion of the frame 10 reaches the roof of the existing building 1. Inside the frame 10, a floor 10c, which is the same floor as the floor from which the existing building 1 has been removed, is provided continuously with the existing floor 1c. Has been.

The frame 10 is constructed with a space provided between it and the surrounding beam 1b forming the space 2.
A damper 15 is interposed between the column beam 1b and the column beam 1b and fixed to both. This damper 15 is generated by the difference in natural period between the existing building 1 and the frame 10.
The vibration energy transmitted to the existing building 1 and the frame 10 is absorbed by being actuated in accordance with the relative change in the distance between the pillars and beams and the wall surface of the frame 10.

When an earthquake motion acts on the existing building 1 having the above-mentioned earthquake-proof reinforcement structure, the existing building 1 and the frame 10 start to vibrate. Here, since the natural period of the frame 10 constructed by the steel frame structure having relatively low horizontal rigidity is set to be longer than the natural period of the existing building 1, the existing building 1 and the frame 10 have their own natural periods. And vibrates at a distance between the pillar beam of the existing building 1 and the wall surface of the frame structure 10 relative to each other.

The damper 15 is a column beam 1b of the existing building 1.
It operates according to the relative change of the space between the frame and the wall of the frame 10, and absorbs the vibration energy transmitted to the existing building 1 and the frame 10, so that the existing building 1 and the frame 10 mutually act as dynamic dampers. It acts and suppresses vibrations to exert a vibration control effect.

Therefore, if the seismic retrofit structure of the existing building as described above is adopted, the existing building 1 and the frame 10 suppress the vibrations of each other and exert the seismic damping effect. It is possible to improve the earthquake resistance of the existing building 1 as a whole.

Further, since the frame structure 10 is built inside the existing building 1, it is not necessary to secure an additional space for providing a reinforcing structure around the existing building 1, and the existing building built in a dense area of the building is required. It is especially effective for objects.

In this embodiment, the frame 10
The structure is a steel frame and is constructed in each of the spaces 2 provided at the four corners of the existing building 1. However, the structure of the frame, the construction position inside the existing building 1, etc. are arbitrarily considered in consideration of the vibration characteristics of the existing building 1. Shall be selected.

Next, a second embodiment of the seismic retrofit structure for an existing building according to the present invention will be described with reference to FIG. The same components as those described in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.
Of the existing building 1 shown in FIG. 3, the floors of the sections located at the four corners of the floors from the first floor to the third floor are removed leaving the surrounding pillar beams 1b, whereby the foundation 1 is installed at the four corners of the existing building 1.
A space 2 is formed that penetrates vertically from a to the third floor.

In this space 2, a frame 20 extending upward along the space 2 is erected on the foundation 1a via a seismic isolation device 21 made of laminated rubber. This frame 20 is a structure of a reinforced concrete image similar to the existing building 1, and has a seismic isolation structure independent of the existing building 1, and the natural period of the frame 20 against earthquake motion is that of the existing building 1. It is set longer than the natural period.

Further, the roof portion 20a of the frame 20 reaches the existing floor 1c on the third floor of the existing building 1, and the interior of the frame 20 is on the same level as the removed floors of the existing building 1 and 2nd floor. The floor 20b is provided continuously with the existing floor 1c.

The frame 20 is constructed with a space provided between it and the surrounding beam 1b forming the space 2.
A damper 25 is interposed between the column beam 1b and the column beam 1b and fixed to both. This damper 25 is generated by the difference in natural period between the existing building 1 and the frame 20.
It is operated in accordance with the relative change in the distance between the column and beam and the wall surface of the frame 20, and absorbs the vibration energy transmitted to the existing building 1 and the frame 20.

When a seismic motion acts on the existing building 1 having the above-mentioned earthquake-proof reinforcement structure, the existing building 1 and the frame 20 start to vibrate. Here, since the natural period of the frame 20 having a seismic isolation structure independent of the existing building 1 is set longer than the natural period of the existing building 1 by the operation of the seismic isolation device 21, The structure 1 and the frame 20 vibrate in their respective natural periods, and the column beam 1 of the existing building 1
The distance between b and the wall surface of the frame 20 relatively changes.

The damper 25 is a pillar beam 1b of the existing building 1.
It operates according to the relative change in the distance between the wall of the frame 20 and the frame 20 and absorbs the vibration energy transmitted to the existing building 1 and the frame 20, so that the existing building 1 and the frame 20 act as dynamic dampers for each other. It acts and suppresses vibrations to exert a vibration control effect.

Therefore, if the seismic retrofit structure of the existing building as described above is adopted, the existing building 1 and the frame 20 suppress the vibrations of each other to exert the seismic damping effect. It is possible to improve the earthquake resistance of the existing building 1 as a whole.

The seismic strengthening structure shown in the present embodiment can construct a large frame by constructing the frame 20 of reinforced concrete, and is effective for a large-scale existing building.

In this embodiment, the frame 20
Was constructed from the lower layer portion of the existing building 1, that is, from the foundation 1a to the third floor, but it is not particularly limited to this position and may be constructed in the middle layer portion or the upper layer portion of the existing building 1.

[0027]

According to the seismic retrofitting structure of an existing building of the present invention, when the existing building and the frame vibrate in their respective natural periods due to earthquake motion, the relative displacement between the column beam and the frame of the existing building occurs. The damper operates accordingly and absorbs the vibration energy transmitted to the existing building and the frame, so that the existing building and the frame act as dynamic dampers to each other and suppress the vibrations to exert the damping effect. It
Therefore, the earthquake resistance of the entire existing building including the frame can be improved. Further, since the frame is built inside the existing building, it is not necessary to secure an additional space around the existing building, and the structure can be applied to an existing building built in a dense area of the building.

[Brief description of drawings]

FIG. 1 is a first example of the seismic retrofit structure for an existing building according to the present invention.
It is a side sectional view showing an embodiment of.

FIG. 2 is a sectional view taken along the line II-II in FIG.

[Fig. 3] Second seismic retrofit structure for existing buildings according to the present invention
It is a side sectional view showing an embodiment of.

[Explanation of symbols]

1 Existing building 1a Basic 2 space 10 frames 15 damper 20 frames 21 seismic isolation device 25 damper G ground

Claims (2)

(57) [Claims] 1. A reinforcing structure for improving the earthquake resistance of an existing building, wherein the floor space of a plurality of rectangular sections formed inside the existing building and partitioned by pillar beams is removed. , A frame whose natural period is different from that of the existing building is erected on the foundation of the existing building with a space between the existing structure and a damper interposed between the frame and the existing building. A seismic retrofit structure for existing buildings. 2. The seismic retrofit structure of an existing building according to claim 1, wherein the frame and the foundation of the existing building.
A seismic isolation structure is installed between the seismic isolation structure and the seismic reinforcement structure of the existing building.