Renovation method

Abstract

To easily construct a foundation for facilities on slabs on intermediate floors when a lower portion of the cut location of an existing column is reused as a column of a renovated building, while easily performing a hook addition work to add hooks to a column head of the existing column, in a renovation method in which upper floors from the intermediate floors to the top floor of the existing building are demolished, lower floors from the bottom floor to the intermediate floors are left as a renovated building, and slabs of the intermediate floors of the existing building are used as roof slabs of the renovated building.SOLUTION: When demolishing upper floors U1, a protruding column section 20, which protrudes above a slab S2 on an intermediate floor 2, is left as a foundation for facilities 31 to be installed on a roof slab S10 of a renovated building 10 in an existing column 3 made of reinforced concrete in an existing building 1, and a hook 22 is added to an upper end of a main bar 5 of the protruding column section 20.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a renovation method in which, in an existing building, the upper floor portion from a middle floor to the top floor is demolished, the lower floor portion from the bottom floor to the middle floor remains as a renovated building after renovation, and the slab of the middle floor of the existing building is used as the rooftop slab of the renovated building.

Background Art

[0002] In an existing building, reduction of floors may be considered in accordance with changes in usage conditions or the like. In a renovation method for such reduction of floors, in the existing building, the upper floor portion from a middle floor to the top floor is demolished, and the lower floor portion from the bottom floor to the middle floor remains as a renovated building after renovation (see, for example, Patent Document 1). Further, when the lower floor portion of the existing building is used as the renovated building as it is, the slab of the middle floor at the top of the lower floor portion is used as the rooftop slab of the renovated building.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a conventional renovation method for reduction of floors as described above, existing columns of an existing building are cut at the height of the slab of the middle floor, and the upper side portion thereof is demolished. That is, in the existing columns of the existing building, the lower side portion of the cutting location remains as the column of the renovated building, and the top of the lower side portion becomes the column head in the renovated building. Therefore, in order to prevent cracking of the concrete in the overlapping portion and reduction of the adhesion force of the main reinforcement bars, it is required to add hooks to the upper ends of the main reinforcement bars of the column head in the renovated building. And, in order to add a hook to the upper end of the main reinforcement bars of the column head in the rebuilt building, it is necessary to chisel the concrete of the column head to expose the upper end of the main reinforcement bars, attach a hook to the exposed upper end of the main reinforcement bars, and place concrete in the chiseled portion to restore the column head, such as in a hook addition operation. And, in the conventional rebuilding method, since the column head in the rebuilt building is the top of the lower part of the cutting location, which is the height of the slab of the intermediate floor used as the rooftop slab of the rebuilt building, when performing the above-described hook addition operation of adding a hook to the column head, since the slab of the intermediate floor exists around the chiseled portion, there is a problem that the workability is very poor. Also, even when constructing a new foundation for equipment on the slab of the intermediate floor that becomes the rooftop slab in the rebuilt building, complicated work such as chiseling a part of the slab of the intermediate floor and embedding an anchor is required. In view of this actual situation, the main problem of the present invention is that in an existing building, the upper floor portion from the intermediate floor to the top floor is demolished, and the lower floor portion from the bottom floor to the intermediate floor remains as a rebuilt building, and in a rebuilding method of using the slab of the intermediate floor of the existing building as the rooftop slab of the rebuilt building, when reusing the lower part of the cutting location of the existing column as the column of the rebuilt building, while easily performing the hook addition operation of adding a hook to the column head, the point is to provide a technique for easily constructing a foundation for equipment on the slab of the intermediate floor.

Means for Solving the Problem

[0005] A first characteristic configuration of the present invention is that in an existing building made of reinforced concrete, the upper floor portion from the intermediate floor to the top floor is demolished, and the lower floor portion from the bottom floor to the intermediate floor remains as a rebuilt building, which is a rebuilding method of using the slab of the intermediate floor of the existing building as the rooftop slab of the rebuilt building, and when demolishing the upper floor portion, in the existing reinforced concrete columns of the existing building, the protruding column portion protruding above the slab of the intermediate floor is left as a foundation for equipment installed on the rooftop slab of the rebuilt building, and a hook is added to the upper end of the main reinforcement bars of the protruding column portion.

[0006] According to this configuration, when demolishing the upper floor part of an existing building, in the existing columns made of reinforced concrete in the existing building, a protruding column part that protrudes above the intermediate floor slab to be used as the roof slab of the rebuilt building remains, and this protruding column part becomes the column head in the rebuilt building. And since there is no intermediate floor slab around the protruding column part, it is possible to easily add a hook to the upper end of the main reinforcement of this protruding column part without the intermediate floor slab getting in the way. Furthermore, the protruding column part that protrudes above the intermediate floor slab to be used as the roof slab of the rebuilt building can be effectively used as a foundation for facilities installed on the roof slab of the rebuilt building, omitting or simplifying the additional construction work for another foundation for facilities, and contributing to the effective use of the space on the new roof slab. Therefore, according to the present invention, in an existing building, in a renovation method of demolishing the upper floor part from the intermediate floor to the top floor and leaving the lower floor part from the bottom floor to the intermediate floor as the rebuilt building, and using the intermediate floor slab of the existing building as the roof slab of the rebuilt building, when reusing the lower side part of the cutting location of the existing column as the column of the rebuilt building, it is possible to provide a technique for easily constructing a foundation for facilities on the intermediate floor slab while easily performing the hook addition work of adding a hook to the column head.

[0007] The second characteristic configuration of the present invention is that when adding the hook to the upper end of the main reinforcement of the protruding column part, an anchor penetrating horizontally is embedded in the protruding column part, and using this anchor, an equipment pedestal for installing the equipment is fixed to the side surface of the protruding column part.

[0008] According to this configuration, even when the protruding height of the protruding column portion with respect to the slab of the intermediate floor used as the rooftop slab of the building after renovation is relatively large in consideration of the workability of the hook addition work, an anchor is embedded together with the addition of a hook to the protruding column portion, and an equipment pedestal is fixed to the side surface of the protruding column portion using the anchor, and equipment is installed on the equipment pedestal, so that the installation height of the equipment installed on the rooftop slab of the building after renovation can be suppressed as low as possible.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0010] Embodiments of the present invention will be described with reference to the drawings. The renovation method of this embodiment (hereinafter referred to as "this renovation method") is for the purpose of demolishing the upper floor portion U1 from the intermediate floor 2 to the top floor in the existing building 1 made of reinforced concrete as shown in FIG. 1. In the existing building 1, the upper floor portion U1 from the intermediate floor 2 to the top floor is disassembled, and the lower floor portion L1 from the bottom floor to the intermediate floor 2 is left as the building 10 after renovation, and the slab S2 of the intermediate floor 2 of the existing building 1 is used as the rooftop slab S10 of the building 10 after renovation.

[0011] And in this renovation method aimed at reducing the building area, the existing reinforced concrete column 3 of the existing building 1 is cut at the cutting point p which is the boundary between the upper floor part U1 and the lower floor part L1 in the intermediate floor 2, and the upper floor part U1 is demolished. That is, the existing column 3 of the existing building 1 has the part below the cutting point p remaining as the column 3A of the renovated building 10, and the top of the remaining column 3A becomes the column head in the renovated building 10. Therefore, in the renovated building 10 (see Fig. 6), in order to prevent cracking of the concrete in the lapped part and reduction of the adhesion force of the main reinforcement 5 at the column head of the column 3A, it is required to add a hook 22 to the upper end of the main reinforcement 5 of the column head. Also, when constructing a foundation for new equipment 31 on the slab S2 of the intermediate floor 2 which becomes the roof slab S10 in the renovated building 10, complicated work such as chiseling a part of the slab S2 of the intermediate floor 2 and embedding an anchor is required. Therefore, in this renovation method, when reusing the lower part of the cutting point p of the existing column 3 as the column 3A of the renovated building 10, a configuration is adopted to easily construct a foundation for the equipment 31 on the slab S2 of the intermediate floor 2 while easily implementing the hook 22 addition work of adding the hook 22 to the column head, and the details thereof will be described below.

[0012] In this renovation method, for the existing building 1, the renovated building 10 is completed by sequentially implementing the following first step (see Fig. 2), second step (see Fig. 3), third step (see Fig. 4), fourth step (see Fig. 5), and fifth step (see Fig. 6). Hereinafter, each step will be described in order.

[0013] (First Step) As shown in Fig. 2, in the first step, in the existing building 1, the upper floor part U1 from the intermediate floor 2 to the top floor is demolished. At this time, the existing column 3 of the existing building 1 is cut at a predetermined cutting location p on the intermediate floor 2. And the cutting location p of this existing column 3 is, for example, about 1 m above the slab S2 of the intermediate floor 2. That is, the protruding column part 20 that protrudes above the slab S2 of the intermediate floor 2 in the column 3A which is the existing column 3 after cutting remains as a foundation for the equipment 31 installed on the roof slab S10 of the rebuilt building 10 as shown in Fig. 1. Also, when cutting the existing column 3, the main reinforcement 5 embedded in the existing column 3 is also cut at the cutting location p. The cutting operation of the existing column 3 at this cutting location p is easily carried out without the slab S2 getting in the way because the cutting location p is a location spaced upward from the slab S2 of the intermediate floor 2.

[0014] (Second step) As shown in Fig. 3, in the second step, in the column 3A after cutting, the existing concrete part C1 which is the concrete part constituting the protruding column part 20 is chiseled with respect to the protruding column part 20 that remains protruding above the slab S2 of the intermediate floor 2. And when the existing concrete part C1 is chiseled, the main reinforcement 5 etc. of the protruding column part 20 are in a state of being exposed. In addition, in this embodiment, although the existing concrete part C1 is chiseled over the entire protruding column part 20 up to the upper surface of the slab S2, within the range that enables the addition of the hook 22 described later, the chiseling range of the existing concrete part C1 may be appropriately changed.

[0015] (Third step) As shown in Fig. 4, in the third step, hooks 22 are added to the upper ends of the main reinforcement bars 5 exposed in the protruding column portion 20 where the existing concrete portion C1 has been chiseled. Note that, for the joining of the hooks 22 to the main reinforcement bars 5, any joining method such as a method using a joint or a method using welding can be adopted. Since the upper ends of the main reinforcement bars 5 in the protruding column portion 20 located at the cutting position p (see Fig. 2) are spaced upward from the slab S2 of the intermediate floor 2, this additional work of the hooks 22 can be easily carried out without the slab S2 getting in the way.

[0016] (Fourth step) As shown in Fig. 5, in the fourth step, a formwork 50 for placing concrete is installed around the protruding column portion 20 to which the hooks 22 have been added. At this time, anchors 25 penetrating horizontally through the protruding column portion 20 are installed in a form supported by the formwork 50. Then, concrete is placed in this formwork 50, and the restored concrete portion C10 constituting the protruding column portion 20 in the renovated building 10 is restored. After restoration, the main reinforcement bars 5 etc. in the column 3A after cutting and the hooks 22 added thereto are completely embedded in the restored concrete portion C10, and the anchors 25 are embedded in the restored concrete portion C10 with their ends protruding laterally from both side surfaces 20a of the protruding column portion 20.

[0017] (Fifth step) As shown in Fig. 6, in the fifth step, the slab S2 of the intermediate floor 2 of the existing building 1 is appropriately waterproofed and then used as the rooftop slab S10 of the renovated building 10. And, on the side surface 20a of the protruding column portion 20 restored in the fourth step, an equipment gantry 30 in a horizontal posture on which equipment 31 is installed is fixed using the anchors 25 embedded in the protruding column portion 20. That is, the protruding column portion 20 remaining in a state protruding above the slab S2 of the intermediate floor 2 used as the rooftop slab S10 of the renovated building 10 is effectively utilized as a foundation for the equipment 31 installed on the rooftop slab S10 of the renovated building 10. Furthermore, in consideration of the workability of the hook 22 addition work in the above-described third step, the protruding height of the protruding column portion 20 that protrudes upward from the slab S2 of the intermediate floor 2 and remains after cutting the column 3A in the first step is set to be relatively large. Even in this case, by fixing the equipment pedestal 30 to the side surface 20a of the protruding column portion 20 and installing the equipment 31 on the equipment pedestal 30, the installation height of the equipment 31 installed on the rooftop slab S10 of the rebuilt building 10 is suppressed as low as possible.

[0018] In addition, in the above embodiment, the horizontal anchor 25 is embedded in the protruding column portion 20, and the equipment pedestal 30 is fixed to the side surface 20a of the protruding column portion 20 using the anchor 25. However, the fixing position of the equipment pedestal 30 with respect to the protruding column portion 20 can be changed as appropriate. For example, the equipment pedestal 30 may be fixed to the top of the protruding column portion 20. Further, when the equipment pedestal 30 is unnecessary or when the equipment pedestal 30 can be fixed to another location, the configuration of fixing the equipment pedestal 30 to the protruding column portion 20 may not be adopted.

Explanation of Reference Numerals

[0019] 1 Existing building 2 Intermediate floor 3 Existing column 3A Column 5 Main reinforcement 10 Rebuilt building 20 Protruding column portion 20a Side surface 22 Hook 25 Anchor 30 Equipment pedestal 31 Equipment U1 Upper floor portion L1 Lower floor portion S10 Rooftop slab S2 Slab of intermediate floor

Claims

1. In an existing reinforced concrete building, the upper floor part from the middle floor to the top floor is demolished, and the lower floor part from the bottom floor to the middle floor remains as a rebuilt building after reconstruction, A reconstruction method that uses the slab of the middle floor of the existing building as the rooftop slab of the rebuilt building, When demolishing the upper floor part, in the existing reinforced concrete columns of the existing building, the protruding column part that protrudes above the slab of the middle floor is left as a foundation for equipment installed on the rooftop slab of the rebuilt building, and a hook is added to the upper end of the main reinforcement of the protruding column part. A reconstruction method.

2. When adding the hook to the upper end of the main reinforcement of the protruding column part, an anchor penetrating horizontally is embedded in the protruding column part, and using the anchor, an equipment pedestal for installing the equipment is fixed to the side surface of the protruding column part. The reconstruction method according to claim 1.

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