Construction method of a structure

Abstract

To provide a construction method of a structure that can be constructed in short duration.SOLUTION: A construction method of a structure is the construction method of a reinforced-concrete made structure that comprises a precast girder locating step of locating multiple precast girders 2 extending to the first direction X apart from each other in the second direction Y orthogonal to the first direction X between columns 1 located apart from each other in the first direction X, and a conventional girder locating step of locating multiple conventional girders 3 extending to the second direction Y apart from each other in the first direction X by site work between the columns 1 located apart from each other in the second direction Y.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a construction method of a structure.

Background Art

[0002] Conventionally, in a structure made of reinforced concrete, by using precast members (PCa members) prefabricated in a factory or on-site in advance, it has been possible to perform construction in a shorter period than the conventional method (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, if all members are composed of precast members, for example, after installing a precast large beam extending in one direction and completing the joining work between the precast large beam and the column, a precast large beam in a direction orthogonal to the one direction will be installed. For this reason, the work of installing the precast large beam in the orthogonal direction is after the completion of the joining work between the precast large beam extending in one direction and the column, and there is a problem that the process cannot be advanced efficiently.

[0005] Therefore, the present invention has been made in view of the above circumstances, and provides a construction method of a structure capable of construction in a short period.

Means for Solving the Problems

[0006] In order to achieve the above object, the present invention employs the following means. That is, the construction method of the structure according to the present invention is a construction method of a reinforced concrete structure, and between columns installed at intervals in a first direction, precast main beams extending in the first direction are installed in a plurality at intervals in a second direction orthogonal to the first direction, which is a precast main beam installation step, and between the columns installed at intervals in the second direction, existing main beams extending in the second direction are installed in a plurality by on-site construction at intervals in the first direction, which is an existing main beam installation step. A precast small beam installation step of installing a precast small beam extending in the first direction between existing large beams installed at intervals in the first direction; a precast slab installation step of installing a precast slab between the precast small beam and the precast large beam adjacent to one side in the second direction; and an existing slab installation step of installing an existing slab on-site between the precast small beam and the precast large beam adjacent to the other side in the second direction. It includes.

[0007] In the construction method of the structure configured in this way, in the precast main beam installation step, the precast main beam is installed between columns installed at intervals in the first direction. In the existing main beam installation step, the existing main beam is installed between columns installed at intervals in the second direction. While performing the joining work between the precast main beam and the column, it is possible to perform work such as installing the formwork of the existing main beam and arranging the main reinforcement bars and stirrups of the existing main beam. That is, since the precast main beam installation step and the existing main beam installation step can be performed in parallel, the work can be efficiently advanced and the construction can be completed in a short period of time. Also, in the precast slab installation step, the precast slab is installed between the precast small beam and the precast large beam adjacent to one side in the second direction. In the existing slab installation step, the existing slab is installed between the precast small beam and the precast large beam adjacent to the other side in the second direction. While the installation work of the precast slab is being carried out, work such as installing the formwork of the existing slab or placing the concrete of the existing slab can be performed. That is, since the precast slab installation step and the existing slab installation step can be carried out in parallel, the work can be advanced efficiently and the construction can be completed in a short period. Also, by using precast slabs, the installation and removal of formwork on-site and the labor for installing the shoring for the formwork can be reduced. Also, by using a combination of precast slabs and existing slabs rather than using only precast slabs for the entire floor, the cost can be suppressed.

[0010] Further, the construction method of the structure according to the present invention may include a concrete placing step of placing concrete on the precast main beam, the existing main beam, the precast secondary beam, the precast slab, and the existing slab.

[0011] In the construction method of the structure configured in this way, in the concrete placing step, concrete is placed on the precast main beam, the existing main beam, the precast secondary beam, the precast slab, and the existing slab. Therefore, since the necessary concrete portions of the precast main beam, the existing main beam, the precast secondary beam, the precast slab, and the existing slab can be placed and constructed at once, the concrete placing work can be efficiently performed. In addition, the precast slab is a half-precast slab in which a part is prefabricated at a factory or on-site in advance, and the remaining part is constructed on-site including a concrete placing process or the like. Since it is lighter than a full-precast slab that is all prefabricated at a factory or on-site in advance, the load during transportation can be suppressed, and the size of a hoisting machine such as a tower crane used during hoisting on-site can be suppressed.

[0012] In addition, in the construction method of the structure according to the present invention, the structure has a shape in which the first direction is longer than the second direction in plan view, and in a region other than the core part, a beam extending in the second direction may not be installed at the center in the second direction.

[0013] In the construction method of the structure configured in this way, since a beam extending in the second direction is not installed at the center in the second direction, the work of installing the beam is reduced. When installing an existing beam on-site at the center in the second direction, a formwork is required, but in the above construction method of the structure, since an existing beam is not installed at the center in the second direction, the formwork is not required, so the types of formwork for the entire structure can be suppressed. In addition, since there is no beam at the center in the second direction, the facility plan such as ducts extending in the first direction can be concentrated at the center in the second direction. When a duct is arranged at the center in the second direction when there is a beam extending in the second direction at the center in the second direction, the duct will pass under the beam and the ceiling height will become low. In the above construction method of the structure, since there is no beam extending in the second direction at the center in the second direction, the ceiling height can be ensured. In addition, since the facility plan is concentrated at the center in the second direction, it is not necessary to pass the duct under the precast main beam and the existing main beam, and the ceiling height under the precast main beam and the existing main beam can be ensured.

Advantages of the Invention

[0014] According to the construction method of the structure according to the present invention, construction can be performed in a short period of time.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0016] A construction method of a structure according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing a structure which is an object of a construction method of a structure according to an embodiment of the present invention. First, the structure which is an object of the construction method of the structure of the present embodiment will be described. As shown in FIG. 1, the structure 100 of the present embodiment is made of reinforced concrete. The structure 100 is a very slender building such that the value of the width to the height (aspect ratio) exceeds 8, but it is also applicable to buildings with an aspect ratio of 8 or less.

[0017] The structure 100 is substantially rectangular in plan view. The long side direction of the structure 100 which is rectangular in plan view is defined as the X direction (first direction), and the short side direction is defined as the Y direction (second direction).

[0018] In the structure 100, the center in the X direction is the core part 100A. In the core part 100A, facilities extending in the vertical direction such as the staircase 101 and the elevator 102 are installed. In the structure 100, the part other than the core part 100A is referred to as the main part 100B.

[0019] A plurality of PCa (precast) columns 1 are installed at intervals in the X direction and the Y direction. The PCa column 1 is a member prefabricated in a factory or on-site in advance. In the Y direction, four PCa columns 1 are arranged. The span L1 (the distance between the PCa columns 1) on the central side in the Y direction is shorter than the span L2 on both end sides in the Y direction. For example, L1 is 4.2 m and L2 is 7.0 m. In the X direction, the PCa columns 1 are arranged at equal spans.

[0020] Between the PCa columns 1 arranged at intervals in the X direction, a PCa large beam (precast large beam) 2 extending in the X direction is installed. The PCa large beam 2 is a member prefabricated in a factory or on-site in advance and integrated with the column-beam joint part.

[0021] In the span L2 on both end sides in the Y direction, between the PCa columns 1 arranged at intervals in the Y direction, an existing large beam 3 extending in the Y direction is installed. The existing large beam 3 is a member constructed on-site.

[0022] In the main part 100B, in the span L1 on the central side in the Y direction, between the PCa columns 1 arranged at intervals in the Y direction, no beam extending in the Y direction such as the existing large beam 3 or the PCa large beam is installed.

[0023] In the core part 100A, in the span L1 on the central side in the Y direction, there are locations where an existing large beam 3 extending in the Y direction is installed between the PCa columns 1 arranged at intervals in the Y direction. Also, there are locations where an existing large beam 3 extending in the X direction is installed between the PCa columns 1 arranged at intervals in the X direction. In the core part 100A, there are locations where seismic walls 4 along the X direction and the Y direction are installed. The seismic wall 4 is a member constructed on-site.

[0024] In the main part 100B, precast small beams 5 (precast concrete small beams) extending in the X direction are installed between the existing large beams 3 spaced apart in the X direction. The precast small beams 5 are members prefabricated in a factory or on-site in advance.

[0025] In the main part 100B, in the spans L2 on both end sides in the Y direction, a precast concrete slab 6 (precast slab) is installed between one of the two precast large beams 2 and the precast small beam 5. In this embodiment, the precast concrete slab 6 is installed between the precast large beam 2 on the central side in the Y direction (referred to as "central side precast large beam 2A") of the two precast large beams 2 and the precast small beam 5. The precast concrete slab 6 is a member at least partially prefabricated in a factory or on-site in advance with an integrated upward rise around the water area. In other locations, an existing slab 7 is installed. The existing slab 7 is a member constructed on-site.

[0026] Next, a construction method of the structure will be described. First, a precast column installation process is performed. FIG. 2 is a diagram for explaining the construction method of the structure and shows the precast column installation process. As shown in FIG. 2, a plurality of precast columns 1 are installed on the floor to be constructed, spaced apart in the X direction and the Y direction. A grout agent is filled into the couplers (not shown) at the column foot portions. The precast column 1 has a plurality of column main reinforcement bars 11 extending in the vertical direction, stirrups (not shown) surrounding the plurality of column main reinforcement bars 11, and a column concrete portion 12 embedding the column main reinforcement bars 11 and the stirrups. The upper part 11u of the column main reinforcement bar 11 protrudes above the upper surface 12u of the column concrete portion 12. Note that the column may be a column constructed on-site instead of a precast member.

[0027] Next, a precast large beam installation process is performed. FIG. 3 is a diagram for explaining the construction method of the structure and shows the precast large beam installation process. As shown in Fig. 3, a plurality of PCa girders 2 extending in the X direction are installed at intervals in the X direction between the PCa columns 1 installed at intervals. A PCa girder 2 integrated with a column-beam joint portion 26 is installed on the upper portions of the PCa columns 1 adjacent to each other in the Y direction. The upper portion 11u of the column main reinforcement 11 of the PCa column 1 is joined to the column-beam joint portion 26. The PCa girder 2 has a plurality of beam main reinforcements 21 extending in the X direction, stirrups 22 surrounding the plurality of beam main reinforcements 21, and a beam concrete portion 23 embedding the beam main reinforcements 21 and the stirrups 22. The upper portions of the beam main reinforcements 21 and the stirrups 22 arranged on the upper side are exposed above the upper surface of the beam concrete portion 23. The beam main reinforcements 21 of the PCa girders 2 adjacent to each other in the X direction are joined by a mechanical joint (not shown). A formwork 25 is installed between the PCa girders 2 adjacent to each other in the X direction. The PCa girder 2 is supported by a support member 81. At this stage, concrete is not placed inside the formwork 25.

[0028] Next, a conventional girder installation process is performed. Fig. 4 is a diagram for explaining the construction method of the structure, showing the conventional girder installation process and the precast small beam installation process. As shown in Fig. 4, a plurality of conventional girders 3 extending in the Y direction are installed on-site at intervals in the X direction between the PCa columns 1 installed at intervals in the Y direction. Formworks 31 are installed between the upper portions of the PCa columns 1 adjacent to each other in the Y direction, a plurality of beam main reinforcements 32 extending in the Y direction are installed, and stirrups 33 are installed so as to surround the plurality of beam main reinforcements 32. The formwork 31 is supported by a support member 82. The work of the conventional girder installation process can be performed while the grout filling work of the column-beam joint portion 26 of the PCa girder 2 is being carried out. At this stage, concrete is not placed inside the formwork 31. In addition, in the main part 100B, no conventional girder 3 is installed at the center in the Y direction shown in Fig. 1.

[0029] Next, a precast small beam installation process is performed. A PCa small beam 5 extending in the X direction is installed between the conventional girders 3 installed at intervals in the X direction. Note that the small beam may be a small beam constructed on-site instead of a precast member.

[0030] Next, a precast slab installation process is performed. FIG. 5 is a diagram for explaining a construction method of a structure, showing a precast slab installation process and a conventional slab installation process. As shown in FIG. 5, a PCa slab 6 is installed between a PCa small beam 5 and a precast large beam 2 adjacent to one side in the Y direction. The PCa slab 6 has a floor concrete portion 60 filled with concrete in a flat plate shape.

[0031] Next, a conventional slab installation process is performed. A conventional slab 7 is installed on-site between a PCa small beam 5 and a PCa large beam 2 adjacent to the other side in the Y direction. A formwork (not shown) is installed, and concrete is placed to form a floor concrete portion 70. The work of the conventional slab installation process can be performed while the work of the precast slab installation process is being carried out.

[0032] Next, a floor reinforcement installation process is performed. FIG. 6 is a diagram for explaining a construction method of a structure, showing a precast column installation process on the upper floor. As shown in FIG. 6, a plurality of main reinforcements 61 extending in the X direction (or Y direction) and a plurality of distribution reinforcements 62 extending in the Y direction (or X direction) are installed on the upper sides of the PCa slab 6 and the conventional slab 7.

[0033] Next, a precast column installation process on the upper floor is performed. While the floor reinforcement installation process is being carried out, a PCa column 1 on the upper floor is installed. A grouting agent is filled into a coupler (not shown) at the column base portion.

[0034] Next, a concrete placing process is performed. While the upper precast column installation process is being carried out, as soon as the floor reinforcement installation process is completed, concrete is placed in the PCa large beam 2, the existing large beam 3, the PCa small beam 5, the PCa slab 6 and the existing slab 7. The formwork 25 between adjacent PCa large beams 2 is filled with concrete. The main beam reinforcement 32 and the main beam reinforcement 32 of the existing large beam 3 are embedded in the concrete. The main reinforcement 61 and the distribution reinforcement 62 of the PCa slab 6 and the existing slab 7 are embedded in the concrete. The upper concrete part 71 is continuously filled in the PCa large beam 2, the existing large beam 3, the PCa small beam 5, the PCa slab 6 and the existing slab 7. In this embodiment, the PCa slab 6 is a half PCa slab in which the floor concrete part 60 is prefabricated in a factory or on-site in advance, and the main reinforcement 61 and the distribution reinforcement 62 are arranged on the upper side of the floor concrete part 60 at the construction site, and concrete is placed so as to embed the main reinforcement 61 and the distribution reinforcement 62 to complete the floor slab.

[0035] Next, on the upper floor, the above precast large beam installation process is sequentially advanced. The installation process of the seismic wall 4 is also advanced.

[0036] According to the structure and the construction method of the structure configured in this way, in the precast large beam installation process, the PCa large beam 2 is installed between the PCa columns 1 installed at intervals in the X direction. In the existing large beam installation process, the existing large beam 3 is installed between the PCa columns 1 installed at intervals in the Y direction. While the joining operation between the PCa large beam 2 and the PCa column 1 is being carried out, operations such as installing the formwork 31 of the existing large beam 3 and arranging the main beam reinforcement 21 and the stirrup 22 of the existing large beam 3 can be performed. That is, since the precast large beam installation process and the existing large beam installation process can be carried out in parallel, the work can be efficiently advanced and the construction can be completed in a short period of time.

[0037] In the precast slab installation process, the PCa slab 6 is installed between the PCa joist 5 and the PCa girder 2 adjacent to one side in the Y direction. In the conventional slab installation process, the conventional slab 7 is installed between the PCa joist 5 and the PCa girder 2 adjacent to the other side in the Y direction. While the installation work of the PCa slab 6 is being carried out, work such as installing the formwork of the conventional slab 7 or placing the concrete of the conventional slab 7 can be performed. That is, since the precast slab installation process and the conventional slab installation process can be carried out in parallel, the work can be efficiently advanced and the construction can be completed in a short period of time.

[0038] Also, by using the PCa slab 6, the installation and removal of the formwork on site and the labor for installing the shoring for the formwork can be reduced.

[0039] Also, by using the PCa slab 6 and the conventional slab 7 in combination rather than making the entire floor the PCa slab 6, the cost can be suppressed.

[0040] In the concrete placement process, concrete is placed on the PCa girder 2, the conventional girder 3, the PCa joist 5, the PCa slab 6, and the conventional slab 7. Therefore, since the upper concrete part 71 required for the PCa girder 2, the conventional girder 3, the PCa joist 5, the PCa slab 6, and the conventional slab 7 can be placed and constructed at one time, the concrete placement work can be efficiently performed.

[0041] The PCa slab 6 is a half-precast slab in which a part is prefabricated at a factory or on site in advance, and the remaining part is constructed on site including the concrete placement process. Since it is lighter than a full-precast slab that is all prefabricated at a factory or on site in advance, the load for transportation can be suppressed, and the size of a hoisting machine such as a tower crane used for hoisting on site can be suppressed.

[0042] In addition, since no beam extending in the Y direction is installed at the center in the Y direction, the work of installing the beam is reduced. When installing an existing beam on-site at the center in the Y direction, formwork is required. However, in the construction method of the structure of the present embodiment, since no existing beam is installed at the center in the Y direction, the formwork 31 is not required, so the types of formwork for the entire structure 100 can be suppressed.

[0043] In addition, since there is no beam at the center in the Y direction, equipment plans such as ducts extending in the X direction can be concentrated at the center in the Y direction. When a duct is arranged at the center in the Y direction when there is a beam extending in the Y direction at the center in the Y direction, the duct will pass under the beam and the ceiling height will become low. In the above construction method of the structure, since there is no beam extending in the Y direction at the center in the Y direction, the ceiling height can be ensured. Also, since the equipment plan is concentrated at the center in the Y direction, it is not necessary to pass the duct under the PCa large beam 2 and the existing large beam 3, and the ceiling height below the PCa large beam 2 and the existing large beam 3 can be ensured.

[0044] In addition, the spans of the PCa columns 1 are made uniform in the X direction, and the spans L2 on both sides in the Y direction are made the same in the Y direction. Therefore, the types of shapes of the PCa large beam 2 and the types of shapes of the formwork of the existing large beam 3 can be suppressed.

[0045] In addition, since the seismic wall 4 is installed around and inside the core part 100A, the building rigidity can be ensured.

[0046] Note that the assembly procedures shown in the above-described embodiments, or the various shapes and combinations of the respective constituent members, etc. are examples, and various changes can be made based on design requirements and the like without departing from the gist of the present invention.

[0047] For example, in the above-described embodiment, in the main part 100B, in the span L1 on the central side in the Y direction, no beam extending in the Y direction such as the existing large beam 3 or the PCa large beam is installed on the PCa columns 1 arranged at intervals in the Y direction, but the present invention is not limited to this. A beam with low beam deflection may be installed.

Explanation of reference numerals

[0048] 1…PCa column (column) 2…PCa large beam (precast large beam) 3…Existing large beam 4…Seismic wall 5…PCa small beam (precast small beam) 6…PCa slab (precast slab) 7…Existing slab 100…Structure 100A…Core part 100B…Main part X direction…First direction Y direction…Second direction

Claims

1. A construction method for a reinforced concrete structure, comprising: a precast girder installation step of installing a plurality of precast girders extending in the first direction at intervals in a second direction orthogonal to the first direction between columns installed at intervals in the first direction; a conventional girder installation step of installing a plurality of conventional girders extending in the second direction at intervals in the first direction by on-site construction between the columns installed at intervals in the second direction; a precast joist installation step of installing precast joists extending in the first direction between the conventional girders installed at intervals in the first direction; a precast slab installation step of installing a precast slab between the precast joist and the precast girder adjacent to one side in the second direction; a conventional slab installation step of installing a conventional slab by on-site construction between the precast joist and the precast girder adjacent to the other side in the second direction. A construction method for a structure comprising the above steps.

2. The construction method for a structure according to claim 1, further comprising a concrete placing step of placing concrete on the precast girder, the conventional girder, the precast joist, the precast slab, and the conventional slab.

3. The structure has a shape in which the first direction is longer than the second direction in plan view, In a region other than the core part, a beam extending in the second direction is not installed at the center in the second direction. The construction method for a structure according to claim 1 or 2.

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