Skeleton structure of cantilever slab and construction method of vertical wall

Abstract

To provide a skeleton structure of cantilever slab which can omit a form timbering comprising many members of a conventional construction method used when constructing the skeleton of the cantilever slab and a standing wall, and a construction method of a vertical wall.SOLUTION: In a skeleton structure of cantilever slab and a construction method of a vertical wall, the skeleton structure includes a standing wall TW on a tip side of a cantilever slab CS. At the skeleton structure, a vertical wall is installed extending downward from the tip side. A steel bracket 11 for form timbering is joined to a body steel 10. At the steel bracket for form timbering, a form material 16 of a floor surface and a wall form 17 of the standing wall are installed. Reinforcing iron bars are arranged, concrete is placed, the tip side of the steel bracket for form timbering is removed, the form material of the floor surface is removed, a ground of the vertical wall is assembled to the steel bracket for form timbering, and the vertical wall is installed on the ground.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cantilever slab framework and a method for constructing a hanging wall. [Background technology]

[0002] A cantilevered slab is a statically determinate structure used to construct balconies, exterior corridors, driveways, and other features of buildings. The cantilevered slab is fixed at only one edge (base) of the slab. Figure 4 shows an example of a conventional support structure using formwork shoring used to construct the framework of a cantilevered slab and a standing RC wall. As shown in Figure 4, a pair of interconnected vertical support members 51 are supported on the floor surface S1 of the floor directly below the corresponding part of the framework of the cantilevered slab and standing RC wall. The cantilevered slab formwork 60 is supported by its formwork panels joined to multiple crosspieces 61 supported by thick corners 62. The thick corners 62 are supported by pipe supports 56 supported by the vertical support members 51. The pipe supports 56 are supported by horizontal members 52 connected to the vertical support members 51 via thick corners 52a, and are further supported by horizontal tie members 53 connected to the vertical support members 51. The horizontal members 52 are further supported and reinforced by brackets 54 and reinforcing pipes 55 connected to the support members 51. The construction load on the formwork 60 is supported by the above-mentioned supports.

[0003] Patent Document 1 discloses a support structure for intermediate floors, and states that long-term loads such as axial force and bending (bending is only possible when there is a rigid joint, such as in a rigid frame structure or when a cantilever beam is extended from the column), or short-term loads such as horizontal force, act on the columns via the beams, and that in addition to these loads, the load of the intermediate floor is also transmitted to the partitions, and the partitions are subjected to horizontal forces from the intermediate floor, and further, if the partitions are equipped with brackets or the like that support the load of the intermediate floor, the partitions are subjected to further bending (paragraph

[0008] , Figure 4). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-82090 Summary of the Invention [Problem to be solved by the invention]

[0005] The conventional construction method shown in Figure 4 incurs labor and equipment-related costs for temporary construction and formwork construction. A large amount of temporary materials is required to install formwork shoring from floor S1 and other locations directly below the affected area, necessitating significant labor and storage space. Furthermore, a large amount of work at height is required. Installing shoring from floor S1 creates limitations, such as the inability to use the area as a work space until the shoring on the floor directly below can be dismantled, hindering efficient construction. Problems include the large number of temporary and shoring materials, the labor required, the risk of accidents during work at height, and the need to secure sufficient work space. While formwork shoring, including the vertical support members 51 shown in Figure 4, may be installed directly below the cantilever slab, this also requires a large amount of temporary materials for the formwork shoring. Patent Document 1 does not disclose formwork shoring used in constructing the skeleton structure of a cantilever slab.

[0006] In view of the problems of the prior art as described above, the present invention aims to provide a method for constructing a cantilever slab framework and a vertical wall that can omit the formwork support consisting of many components used in conventional construction methods when constructing the framework of a cantilever slab and a vertical wall. [Means for solving the problem]

[0007] The method for constructing the cantilever slab framework and hanging walls to achieve the above objectives is as follows: The skeleton structure has a rising wall at the tip side of the cantilever slab, and a hanging wall extending downward from the tip side is installed in the skeleton structure, The method includes the steps of joining a support steel bracket to a main steel frame for the cantilever slab, installing floor formwork materials and wall formwork for the vertical wall on the support steel bracket, arranging reinforcing bars in the floor formwork materials and the wall formwork for the vertical wall, pouring concrete into the floor formwork materials and the wall formwork for the vertical wall, removing the tip end of the support steel bracket, removing the floor formwork materials, assembling a base for the hanging wall on the base for the support steel bracket from which the tip end has been removed, and installing the hanging wall on the base.

[0008] According to this cantilever slab framework and hanging wall construction method, floor formwork and vertical wall formwork can be installed on the steel support brackets connected to the main steel frame for the cantilever slab, eliminating the need for the many components required for formwork and shoring in conventional construction methods. This reduces the amount of temporary materials and shoring, the labor required for installing formwork and shoring, and the need for working at height, ensuring work space and improving construction efficiency. Furthermore, the steel support brackets are used to assemble the base for the hanging wall after concrete is poured, reducing the labor required for constructing the hanging wall. As described above, the steel support brackets can be used for both installing the formwork and assembling the base for the hanging wall.

[0009] In the above-mentioned method for constructing the cantilever slab frame structure and hanging wall, the support steel bracket is divided into a removable portion at the tip end and a fixed portion that is fixed to the main steel frame, and the removable portion and the fixed portion are joined together by bolts using a connecting plate, and in the process of removing the tip end of the support steel bracket, it is preferable to release the bolts on the connecting plate and remove the removable portion.

[0010] In the step of attaching a base for the hanging wall, the base is preferably attached to the fixing portion.

[0011] It is preferable that the support steel brackets are joined to the main steel frame in advance at a factory. [Effects of the Invention]

[0012] According to the method for constructing the cantilever slab framework and vertical wall of the present invention, formwork is installed on the steel frame brackets for support joined to the main steel frame, so that the formwork support consisting of many components used in the conventional construction method when constructing the framework of the cantilever slab and vertical wall can be omitted, and the steel frame brackets for support can also be used to assemble the base for the vertical wall. [Brief explanation of the drawings]

[0013] [Figure 1] 1A is a side view showing the main parts such as the support steel frame brackets and formwork joined to the main steel frame used in the method for constructing the cantilever slab frame structure according to this embodiment, FIG. 1B is a plan view seen from direction B, and FIG. 1C is a front view seen from direction C. [Figure 2] 1 is a flowchart for explaining each step of a method for constructing a cantilever slab skeleton structure according to this embodiment. [Figure 3] FIG. 2 is a side view showing the shoring steel bracket hanging wall after the formwork and the removable portion of the shoring steel bracket in FIG. 1 have been removed. [Figure 4] This is a diagram showing an example of a conventional construction method for a support structure using formwork shoring used when constructing the framework of a cantilever slab and a rising wall. [Figure 5] 4A is a side view showing the main part of the supporting steel bracket and hanging wall of FIG. 3, and FIG. 4B is an external view enlarging a part of it to explain the assembled and fixed state of the hanging wall and the base. DETAILED DESCRIPTION OF THE INVENTION

[0014] The following describes an embodiment of the present invention with reference to the drawings. Figure 1 shows a side view (a) of the main parts of the method for constructing a cantilever slab skeleton structure according to this embodiment, such as steel frame brackets for support and formwork joined to the main steel frame, a plan view (b) of the main part as viewed from direction B, and a front view (c) of the main part as viewed from direction C.

[0015] First, we will explain the support steel brackets that are joined to the main steel frame. As shown in Figures 1(a) to 1(c), the main steel frame 10 for the cantilevered slab CS, shown by the dashed line, is installed at the tip of the cantilevered slab CS, extending parallel to the standing wall TW, also shown by the dashed line. The main steel frame 10 has a plate-shaped lower surface 10a, a plate-shaped upper surface 10b, and a plate-shaped connecting portion 10c that connects the lower surface 10a and the upper surface 10b. The cantilevered slab CS and the standing wall TW are reinforced concrete structures (RC structures) and form the skeleton structure.

[0016] A steel support bracket 11 is joined to the main steel frame 10. As shown in Figure 1(c), the steel support bracket 11 is made of a channel steel with a roughly U-shaped vertical cross section, and as shown in Figures 1(a) and 1(b), it is divided into a fixed portion 11a that is connected and fixed to the main steel frame 10, and a removable portion 11b at the tip. The fixed portion 11a and the removable portion 11b are joined together by a connecting plate 12 with multiple bolts and nuts 13. Note that a bracket is a member that is cantilevered from a wall, beam, column, etc. Alternatively, other common steel shapes may be used for the steel support bracket 11.

[0017] The fixing portion 11a of the shoring steel bracket 11 is butted against the plate-shaped connecting portion 10c of the main steel frame 10 so as to be perpendicular thereto, and joined by welding. The upper surface 11c of the shoring steel bracket 11 abuts against the underside of the plate-shaped upper surface portion 10b of the main steel frame 10, but the upper surface 11c may also be welded to the underside of the upper surface portion 10b of the main steel frame 10 at this abutting portion.

[0018] As shown in Figures 1(a) to 1(c), the support steel brackets 11 are attached at multiple locations at predetermined intervals along the longitudinal direction of the main steel frame 10. When constructing the skeleton structure, formwork materials (damming boards) 16 for the floor and wall formwork 17 for the standing wall TW are installed on the top surfaces 11c at the tips of the support steel brackets 11. The support steel brackets 11 are designed to maintain the strength required to construct the skeletons of the cantilever slabs CS and the standing wall TW.

[0019] Next, each step of the method for constructing a cantilever slab skeleton structure according to this embodiment will be described with reference to FIGS. 1 to 3. FIG. 2 is a flowchart for explaining each step S01 to S09 of the method for constructing a cantilever slab skeleton structure according to this embodiment. FIG. 3 is a side view showing the main parts of the shoring steel bracket and hanging wall after the formwork and the removable parts of the shoring steel bracket in FIG. 1 have been removed. FIG. 5 is a side view (a) showing the main parts of the shoring steel bracket and hanging wall in FIG. 3, and an external view (b) enlarging a portion of that view to explain the assembled and fixed state of the hanging wall and base. For convenience of illustration, FIG. 5(b) shows the L-shaped steel 15b of FIG. 5(a) reversed left and right.

[0020] 1(a) to 1(c), the shoring steel brackets 11 are joined to multiple locations of the main steel frame 10 (S01). That is, the fixing portions 11a of the shoring steel brackets 11 are joined to the plate-shaped connecting portions 10c of the main steel frame 10 by welding. This joining is carried out in advance in a factory, and the main steel frame 10 with the shoring steel brackets 11 attached is then transported to the construction site.

[0021] Next, the main steel frame 10 is installed (S02). The main steel frame 10 is installed so that its longitudinal direction is parallel to the end CS1 of the cantilever slab CS, which will be constructed in a subsequent process, extending in the direction perpendicular to the plane of the paper in FIG. 1(a).

[0022] Next, as shown in Figures 1(a) and 1(b), floor formwork materials (damming boards) 16 and wall formwork 17 for the standing wall TW are installed on the top surface 11c of the tip side of the shoring steel bracket 11 (S03). The floor formwork materials 16 and the wall formwork 17 for the standing wall TW are linear in accordance with the linear shape of the standing wall TW. Also, as shown by the dashed line in Figure 1(a), temporary formwork 16a made of steel plate is placed on the top surface 11c side of the shoring steel bracket 11, between the top surface 10b of the main steel frame 10 and the formwork material 16.

[0023] Next, reinforcing bars (not shown) are arranged in the formwork material (dam board) 16 for the floor surface and in the wall formwork 17 for the standing wall TW (S04), and then concrete is poured (S05).

[0024] Next, after the concrete has developed its strength and the framework of the cantilever slab CS and the standing wall TW has been constructed, the removable portion 11b at the tip of the support steel bracket 11 shown in Figure 1(a) is removed by loosening and removing the multiple bolts and nuts 13, and then removing the connecting plate 12 (S06). Next, the formwork material 16 on the floor surface is removed (S07).

[0025] 3 and 5(a), the base 15 of the vertical wall 14 is assembled using the fixing portion 11a of the shoring steel bracket 11 (S08). The base 15 has an L-angle steel member 15a attached to the underside of the fixing portion 11a of the shoring steel bracket 11 by welding or the like, an L-angle steel member 15b arranged to support the vertical wall 14 at its lower end, an L-angle steel member 15c attached to the L-angle steel members 15a and 15b by welding or the like in the vertical direction to reinforce the L-angle steel members 15a and 15b and support the L-angle steel member 15b, and a support member 15d attached to the underside portion 10a of the main steel frame 10 by welding or the like to support the L-angle steel member 15c.

[0026] Next, as shown in Figures 3 and 5(a) and (b), the vertical wall 14 is placed on the L-angle steel members 15b and fixed to the L-angle steel members 15a and 15b with fixing metal fitting assemblies 18, and then installed on the base 15 (S09). The vertical wall 14 is preferably made of a lightweight aerated concrete building material such as an ALC (autoclaved lightweight aerated concrete) panel. As shown in Figure 5(b), the fixing metal fitting assembly 18 is composed of a bolt 18a attached to the L-angle steel members 15a and 15b, an O-nut 18b attached to the bolt 18a, an anchor steel rod 18c penetrating laterally through the O-nut 18b and embedded in the vertical wall 14, and a fixing bolt 18d screwed into the O-nut 18b. The vertical wall 14 can be fixed to the base 15 by screwing the fixing bolt 18d into the O-nut 18b from the back side of the vertical wall 14.

[0027] 3 and 5(a), a gap w is formed between the tip 11d of the fixed part 11a of the shoring steel bracket 11 and the back surface of the vertical wall 14, but the tip 11d may be configured to abut against the back surface of the vertical wall 14, so that the vertical wall 14 is positioned horizontally in the figure. Also, in the shoring steel bracket 11, the position of the tip 11d of the fixed part 11a is the dividing position (joint position) between the fixed part 11a and the removable part 11b.

[0028] According to the method for constructing a cantilever slab skeleton structure of this embodiment, floor formwork materials 16 and wall formwork 17 for the vertical wall TW can be installed on the support steel brackets 11 joined to the main steel frame 10 for the cantilever slab CS, eliminating the need for conventional formwork support, which is made up of many components. This reduces the need for conventional temporary materials and support materials, reduces the labor required to install formwork support in conventional construction methods, improves construction efficiency, and prevents accidents by reducing work at height. Furthermore, because the formwork support required in conventional construction methods can be omitted, the work space on the floor directly below can be used as work space, contributing to efficient construction.

[0029] Furthermore, after pouring concrete, the fixed portion 11a of the steel bracket 11 for shoring, from which the removable portion 11b has been removed, can be used to attach and assemble the base 15 of the vertical wall 14, thereby reducing the labor required for construction of the vertical wall 14. In this way, the steel bracket 11 for shoring can be used both as formwork support and as the base for the vertical wall.

[0030] Although the embodiments for carrying out the present invention have been described above, the present invention is not limited to these, and various modifications are possible within the scope of the technical concept of the present invention. For example, in this embodiment, the planar shapes of the floor formwork material 16 and the wall formwork 17 of the standing wall TW are linear in shape to correspond to the outer wall shape of the linear portion as shown in Figure 1(b), but they may also be configured to have a curved (R-shaped) shape to correspond to the outer wall shape of the R portion. [Industrial Applicability]

[0031] According to the present invention, formwork can be installed on the steel brackets for shoring joined to the main steel frame, and formwork shoring consisting of many components of conventional construction methods can be omitted, which reduces the need for conventional temporary materials and shoring materials, reduces the labor required for installing formwork shoring, and prevents accidents by reducing work at height. Furthermore, the steel brackets for shoring can be used not only for formwork shoring but also as a base for hanging walls, which contributes to efficient construction of the main frame and the efficiency of hanging wall structure construction. [Explanation of symbols]

[0032] 10 Main body steel frame 10a Bottom part 10b Top part 10c connection part 11 Steel frame bracket for support 11a Fixed part 11b Removable parts 11c Top side 12 Joint plate 13 Bolts and nuts 14 Hanging wall 15 Base 15a L-angle steel 15b L-angle steel 15c L-angle steel 15d Support member 16 Formwork material 17 Wall formwork 18 Fixture assembly CS Cantilever Slab TW Standing Wall

Claims

1. A method for constructing a cantilever slab framework and hanging walls, comprising: The body structure has a rising wall on the tip side of the cantilever slab, A vertical wall extending downward from the tip end side is installed on the body structure, A step of joining a support steel bracket to a main steel frame for the cantilever slab; a step of installing a formwork material for a floor surface and a wall formwork for a rising wall on the support steel bracket; a step of arranging reinforcing bars in the formwork material of the floor surface and the wall formwork of the standing wall; Pouring concrete into the formwork material for the floor surface and the wall formwork for the standing wall; A step of removing the tip side of the support steel frame bracket; removing the formwork material from the floor surface; a step of assembling a base for the hanging wall to the support steel bracket from which the tip side has been removed; and a step of installing the hanging wall on the base.

2. The support steel bracket is divided into a removable portion at the tip end and a fixed portion fixed to the main steel frame, and the removable portion and the fixed portion are bolted together with a joining plate to form an integrated unit.

2. The method for constructing a cantilever slab framework and a hanging wall according to claim 1, wherein the bolt connection of the connecting plate is released and the removable portion is removed in the step of removing the tip end side of the support steel bracket.

3. The method for constructing a cantilever slab framework and a hanging wall according to claim 2, wherein the step of attaching a base for the hanging wall includes attaching the base to the fixing portion.

4. 4. A method for constructing a cantilever slab framework and a hanging wall according to claim 1, wherein the support steel brackets are joined to the main steel frame in advance at a factory.

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