JPH09235885A - Seismic retrofit structure of existing building - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide an effective reinforcing structure for improving the earthquake resistance of an existing building. SOLUTION: An extension part 4 mainly composed of a reinforcing frame having higher rigidity and higher yield strength than the existing building is built around the existing building 3 and integrated with the existing building. A large number of earthquake resistant walls 7 are provided in the extension part in a direction orthogonal to the existing outer wall. The extension will be constructed in the form of a gate that covers the entire surface and upper surface of the existing structure. At least the low-rise part of the extension part is constructed in a staircase shape. Install diagonal members between the existing building and the ground in the lower part of the extension.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforcing structure for improving the earthquake resistance of an existing building.

[0002]

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

Many existing buildings, which are relatively old in construction, have high rigidity in the horizontal direction 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 amount of deformation up to the point of failure or to strengthen the proof stress by installing reinforcing elements such as earthquake resistant walls and braces at key points. However, increasing the toughness of existing buildings requires remarkably large-scale renovation work and is almost difficult.
In reality, it is common practice to increase the yield strength by installing earthquake resistant walls and braces inside existing buildings.

[0004]

However, although it is technically relatively easy to provide an earthquake-resistant wall or brace inside an existing building, it is possible to install them on the existing building. It is largely restricted by the plan, and in many cases it is not possible to freely install seismic walls or braces at the required positions because 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.

[0005]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a reinforcing structure for improving the earthquake resistance of an existing building, which is higher than the existing building around the existing building. The present invention is characterized in that an extension section mainly composed of a rigid and high-strength reinforcing frame is constructed integrally with the existing building. A large number of earthquake-resistant walls are provided in the extension part in a direction orthogonal to the existing outer wall of the existing building, or the extension part is constructed so as to cover the entire peripheral surface and the upper surface of the existing structure, or the extension part. It is preferable to construct at least the low-rise portion in a stepwise manner, or to provide the low-rise portion of the extension portion with a diagonal member extending between the existing building and the ground.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the most basic first of the present invention.
1 is a schematic view of an embodiment, (a) is a plan view,
(B) is a vertical sectional view. In the first embodiment, the circumference of an existing building 3 (each floor is shown as a 6-story building with a size of 4 spans × 4 spans) constructed mainly of columns 1 and beams 2 In addition, by constructing a robust extension part 4 integrally so as to surround it, the extension part 4 reinforces the existing building 3 from the outside, thus improving the earthquake resistance of the entire building after the extension. I am trying to let you.

The extension section 4 is erected between the extension column 5 standing on the outermost periphery of the extension column 5 and the existing column 1 located on the outer periphery of the existing building 3. Additional beam 6
And, it is constructed mainly of a robust reinforcing frame composed of a large number of earthquake resistant walls 7 provided in each span of the extension section 4. The extension 4 is provided with a large number of earthquake-resistant walls 7, so that the extension 4 has sufficiently higher rigidity and higher yield strength than the existing building 3. In other words, the dimensions, strengths, and installation positions of the additional columns 5, the additional beams 6, and the earthquake-resistant walls 7 are optimally designed so that the rigidity and proof stress of the extension part 4 can be secured sufficiently larger than that of the existing building 3. In the first embodiment, each earthquake resistant wall 7 is provided so as to be orthogonal to the existing outer wall.

Of course, other reinforcing elements such as braces may be provided instead of providing the load bearing wall 7 in the extension section 4 or in combination with the load bearing wall 7. Although not shown in the drawing, since the extension section 4 needs to be supported on the ground by a strong foundation, it is necessary to add a strong foundation around the existing foundation of the existing building 3. Further, the existing outer wall of the existing building 3 may be appropriately removed to connect the existing part and the extension part 4, but if it is not necessary, it may be left as it is, in consideration of usability after extension. It can be selected arbitrarily.

As described above, by constructing the robust extension part 4 integrally around the existing building 3, the existing building 3
Can be strongly reinforced from its surroundings by the extension portion 4, and therefore, the earthquake resistance of the entire building after the extension can be significantly improved as compared with that before the extension. The existing portion does not need to be modified or changed except that the additional beam 6 is joined to the existing pillar 1 and the existing outer wall is removed as necessary. It can be used without any trouble until then. Of course,
Although each floor of the extension part 4 is divided into spans by the seismic wall 7, it can be used freely for each span, and in particular, in the first embodiment, each seismic wall 7 should be orthogonal to the existing outer wall. Since each span of the extension part 4 is connected to the existing part, the floor area of each floor is increased substantially,
Therefore, it is possible to improve the usability compared to before the extension, and at least the usability is not deteriorated compared to before the extension.

FIG. 2 shows a second embodiment of the present invention. In the above-described first embodiment, the additional portion 4 is provided so as to surround the existing building 3, but in the second embodiment, not only the surrounding area of the existing building 3 but also the upper portion is covered. That is, as shown in FIG. 2, the extension portion 14 is constructed so as to form a gate shape in a vertical sectional view.

That is, according to the second embodiment, the same extension structure 1 as that of the first embodiment is provided around the existing building 3 by the additional columns 15, the additional beams 16 and the earthquake resistant walls (not shown).
In addition to constructing 4a, an extension pillar 15 is added to the upper end of each existing pillar 1 of the existing building 3 by one layer, and an additional beam 16 is erected between the upper ends of the additional pillars 15 and a seismic wall ( By installing (not shown), it is assumed that a robust extension part 14b that connects the tops of the extension parts 14a that cover the upper part of the existing building part 3 and is provided around the existing building part 3 is constructed, and these extension parts 14a, 14b Thus, the entire extension portion 14 that forms a gate shape in a vertical sectional view is constructed. In addition, the extension part 14b provided so as to cover the upper part of the existing building 3
Can be effectively used as an extension floor, and the extension floor is 1
Not only the layers but also two or more layers are possible.

By making the extension part 14 into a gate shape by the extension part 14a around the existing building 3 and the extension part 14b above it, the rigidity and proof stress of the whole extension part 14 is the case of the extension part 14a alone. Therefore, in the second embodiment, even if the depth dimension of the extension portion 14a is reduced as compared with the case of the above-described first embodiment, the same or more reinforcing effect can be obtained. Therefore, it is possible to save the extension area as compared with the case of the first embodiment, and it is suitable when the site around the existing building 3 has little margin.

FIG. 3 shows a third embodiment of the present invention. In the third embodiment, a gate-shaped extension section 24 is provided as in the second embodiment, and the extension section 24 is provided.
The lower-layer part is formed in a stepped shape, and the diagonal member 28 extending between the existing building 3 and the ground is arranged in the stepped lower-layer part. In this case, as in the case of the first and second embodiments, the entire existing building 3 is reinforced by the extension portion 24, and the reinforcement effect is enhanced especially in the stepped low-rise portion, and the earthquake The horizontal force sometimes applied to the existing building 3 is directly received by the diagonal member 28, and therefore, the earthquake resistance of the entire building after the extension can be most efficiently improved. It should be noted that the same effect can be expected only by forming the low-layer portion of the extension portion 24 in a stepped shape without providing the diagonal member 28, or conversely, by providing the diagonal member 28 without forming the low-layer portion in the stepwise shape. However, it is most effective when the low-layer portion is stepped and the diagonal member 28 is incorporated therein as described above, and there are few design problems.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above-mentioned embodiments, and corresponds to the form of the existing building to be reinforced and has the required earthquake resistance. It goes without saying that appropriate design changes can be freely made without departing from the scope of the present invention, depending on the degree.

[0015]

As described above, according to the present invention, since an extension part mainly composed of a reinforcing frame having high rigidity and high proof strength is constructed around an existing building to be integrated with the existing building, It is possible to reinforce the existing building from its surroundings and improve the earthquake resistance without impairing the usability inside the existing building. If a large number of earthquake-resistant walls are provided in the extension portion in a direction orthogonal to the existing outer wall, the floor area can be increased by connecting the existing portion and the extension portion, and the usability can be improved. Also, if the extension part is provided so as to cover not only the entire surface of the existing structure but also the upper surface, the rigidity and proof stress of the extension part itself can be naturally increased by that form, so the extension area can be saved accordingly. You can Furthermore, if at least the low-rise part of the extension part is constructed in a stepwise manner, the reinforcement effect in the low-rise part can be enhanced, and if a low-rise part of the extension part is provided with a diagonal member between the existing building and the ground, Seismic resistance can be most efficiently improved by directly receiving horizontal force from the diagonal members.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

FIG. 3 is a diagram showing a third embodiment of the present invention.

[Explanation of symbols]

 3 Existing buildings 4 Extension section 7 Earthquake-resistant wall 14 Extension section 24 Extension section 28 Diagonal timber

Claims (5)

[Claims] 1. A reinforcement structure for improving seismic resistance of an existing building, wherein the extension part is mainly composed of a reinforcing frame having higher rigidity and higher yield strength than the existing building around the existing building. A seismic retrofit structure for an existing building, characterized by being constructed by integrating the above with the existing building. 2. The seismic strengthening structure for an existing building according to claim 1, wherein a large number of seismic resistant walls are provided in the extension portion in a direction orthogonal to an existing outer wall of the existing building. 3. The seismic reinforcement structure for an existing building according to claim 1, wherein the extension part is constructed so as to cover the entire peripheral surface and the upper surface of the existing structure. 4. The step of constructing at least the lower layer portion of the extension portion in a stepped shape.
Seismic strengthening structure of the existing building described. 5. The seismic retrofitting of an existing building according to claim 1, 2, 3 or 4, wherein a diagonal member extending between the existing building and the ground is provided in a low-rise part of the extension part. Construction.