Construction method

Abstract

To provide a construction method capable of preventing falls that occur when constructing a structure.SOLUTION: A construction method according to one embodiment is a method for constructing a structure 1, and includes the steps of: fixing scaffolding 20 to a precast member 11 that will become a part of the structure 1 so as to protrude from the precast member 11 to create a precast member 10 with scaffolding; and joining a plurality of precast members 10 with scaffolding to each other to construct the structure 1.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a construction method for constructing a structure. [Background technology]

[0002] Patent Document 1 describes a work scaffolding device. The work scaffolding device comprises a pair of gate-shaped frames, a scaffolding board that is spanned between the pair of frames to provide a foothold for workers, and a pair of temporary cross members that connect the pair of frames to each other above the scaffolding boards. The work scaffolding device is used when performing elevator installation work. Braces are placed between the pair of frames, and an assembly consisting of the frames and braces is assembled in the elevator hoistway to the height of the elevator.

[0003] Patent Document 2 describes a prefabricated temporary scaffolding device. The prefabricated temporary scaffolding device includes a plurality of guide rails laid parallel to one another and a temporary scaffold having a plurality of running wheels that can run along the guide rails. The temporary scaffolding is placed in the transverse or longitudinal direction within a building. The load of the temporary scaffolding is ultimately supported by the floor surface of the building via the plurality of running wheels and guide rails.

[0004] Patent Document 3 describes a temporary scaffolding. The temporary scaffolding includes a plurality of support columns and a plurality of auxiliary columns, a fabric member extending horizontally between the plurality of support columns, a plurality of brackets connecting the support columns and auxiliary columns to one another, and a step plate forming a scaffolding passageway. The step plate is fixed to an area defined by the fabric member and a pair of brackets. An access opening and a ladder are provided between the pair of horizontally aligned scaffolding passageways, allowing workers to move between the upper and lower scaffolding passageways through the access opening and the ladder. A gap is formed between the scaffolding passageway and the building to be constructed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 3916498 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-371705 [Patent Document 3] Patent No. 4083617 Summary of the Invention [Problem to be solved by the invention]

[0006] It is known that falls are a common occupational accident in the construction industry. Of these falls, many occur from scaffolding. Therefore, safety management at construction sites requires the prevention of falls. In the temporary scaffolding mentioned above, gaps are formed between the scaffolding and the building, and falls often occur through these gaps.

[0007] The present disclosure aims to provide a construction method that can prevent falls that occur when constructing a structure. [Means for solving the problem]

[0008] (1) A construction method according to the present disclosure is a method for constructing a structure, comprising the steps of: fixing scaffolding to precast members that will become part of the structure so that the scaffolding protrudes from the precast members to create precast members with scaffolding attached; and joining multiple precast members with scaffolding attached to each other to construct the structure.

[0009] In this construction method, a structure is constructed by joining multiple precast scaffolding-attached members together, and each precast scaffolding-attached member comprises a precast member that becomes part of the structure and a scaffolding. In each precast scaffolding-attached member, the scaffolding is fixed to the precast member so as to protrude from the precast member. By fixing the scaffolding so as to protrude from the precast member that becomes part of the structure, gaps formed between the scaffolding and the structure are eliminated. This prevents falls from occurring through gaps formed between the scaffolding and the structure, thereby preventing falls that occur when constructing the structure. Furthermore, because the precast members of each precast scaffolding-attached member become part of the structure, the installation and removal of formwork for constructing the structure is unnecessary. Furthermore, because the scaffolding is fixed to the precast members in advance, the assembly work of the scaffolding at high altitudes is unnecessary. This reduces the amount of work required for work at high altitudes using scaffolding, contributing to improved safety.

[0010] (2) In the above (1), in the process of constructing the structure, the structure may be constructed by stacking multiple precast members with scaffolding in the vertical direction. In this case, the structure is constructed by stacking the precast members with scaffolding in the vertical direction. This eliminates gaps between the scaffolding and the structure in each of the stacked precast members with scaffolding, thereby more reliably preventing falls and reducing the amount of work required at height.

[0011] (3) In the above (1) or (2), the construction method may include a step of removing the scaffolding from the precast members after constructing the structure. In this case, the scaffolding can be reused by fixing the removed scaffolding to another precast member.

[0012] (4) In the above (3), in the process of constructing a structure, a structure may be constructed by stacking multiple precast members with scaffoldings in the vertical direction, and in the process of removing the scaffoldings, the scaffoldings may be removed in order, starting with the precast member with scaffoldings located vertically above. In this case, the scaffoldings are removed in order, starting with the precast member with scaffoldings located vertically above. Therefore, a worker standing on a precast member with scaffolding can remove the scaffoldings of the precast member with scaffoldings above him, while also removing the scaffoldings from above. This allows the scaffolding removal work to be carried out efficiently.

[0013] (5) In any of the above (1) to (4), the scaffolding may be foldable toward the precast member. In this case, by folding the scaffolding, the scaffolding protruding from the precast member can be prevented from getting in the way when lifting the precast member with the scaffolding. Furthermore, by folding the scaffolding to lift the precast member with the scaffolding, it is possible to easily construct a structure even in a narrow site.

[0014] (6) In any of the above (1) to (5), the precast members may have holes through which the main reinforcing bars of the structure are passed. In this case, when multiple precast members with scaffolding are joined, the main reinforcing bars of the structure are passed through the holes of each precast member, thereby enabling efficient construction of the structure.

[0015] (7) In the above (6), the construction method may include a step of forming insertion holes into which the main reinforcing bars of the structure are inserted in a surface member located below the scaffolding-attached precast member, and embedding mechanical anchors into which the main reinforcing bars are fixed. In the step of constructing the structure, the scaffolding-attached precast member may be placed on top of the surface member, and the main reinforcing bars passed through the holes and the insertion holes may be fixed to the mechanical anchors. In this case, the main reinforcing bars passed through the holes in the scaffolding-attached precast member placed on top of the surface member can be fixed to the mechanical anchors embedded in the surface member. This makes it easy to place and fix the main reinforcing bars of the structure, making it even easier to construct the structure.

[0016] (8) In the above (1), the step of constructing a structure may include a step of arranging multiple scaffold-attached precast members along a horizontal juxtaposition direction. The scaffold-attached precast members may have protruding portions that protrude from the ends of the scaffold-attached precast members in the juxtaposition direction and have horizontal rebars embedded therein that extend along the juxtaposition direction. In the step of arranging the scaffold-attached precast members, the scaffold-attached precast members may be arranged so that the protruding portions face other scaffold-attached precast members. The construction method may include, after the step of arranging the scaffold-attached precast members, a step of arranging splice rebars in spaces aligned with the protruding portions along a horizontal direction perpendicular to the juxtaposition direction, so that the splice rebars extend in the juxtaposition direction together with the horizontal rebars, and a step of pouring concrete into the spaces where the splice rebars are arranged. In this case, the scaffold-attached precast members have protruding portions, and the scaffold-attached precast members are arranged so that the protruding portions face other scaffold-attached precast members along the juxtaposition direction. By arranging the protrusions facing other scaffolding-equipped precast members, the distance between the multiple scaffolding-equipped precast members can be reduced, thereby reducing the gaps between the multiple scaffolding-equipped precast members. This prevents people from falling through gaps formed between the multiple scaffolding-equipped precast members and reduces the amount of formwork required when pouring concrete between the multiple scaffolding-equipped precast members. Furthermore, in the spaces aligned with the protrusions in the perpendicular direction, joint rebars are arranged to extend in the parallel direction together with the horizontal rebars, and concrete is poured into those spaces. By arranging the joint rebars aligned in the perpendicular direction to the horizontal rebars, gap lap joints can be formed between the multiple scaffolding-equipped precast members, thereby ensuring appropriate stress transfer between the multiple scaffolding-equipped precast members.

[0017] (9) In the above (8), the scaffolding-attached precast members may have a plurality of protrusions aligned along the orthogonal direction and spaces formed between the plurality of protrusions. In this case, by forming spaces between the plurality of protrusions aligned along the orthogonal direction, it is possible to further reduce the gaps between the plurality of scaffolding-attached precast members and further reduce the need for formwork when pouring concrete into the spaces.

[0018] (10) In the above (8) or (9), in the step of arranging the scaffolding-attached precast members, the scaffolding-attached precast members may be arranged so that the protruding portions face each other along the arranging direction, and gaps may be formed between the protruding portions. In this case, the joint reinforcing bars can be easily arranged by inserting a hand or the like through the gaps.

[0019] (11) In any of the above (8) to (10), the construction method may include a step of fixing a splice reinforcing bar to a shear reinforcement bar protruding perpendicularly from the protruding portion. The step of placing the splice reinforcing bar may include a step of removing the splice reinforcing bar fixed in the fixing step from the shear reinforcement bar and sliding the splice reinforcing bar toward another precast member with scaffolding. In this case, the splice reinforcing bar can be fixed to the shear reinforcement bar of the precast member with scaffolding in advance. Furthermore, by removing the splice reinforcing bar from the shear reinforcement bar and sliding it, the placement of the splice reinforcing bar can be easily performed. [Effects of the Invention]

[0020] According to the present disclosure, it is possible to prevent falls that occur when constructing a structure. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a side view showing an example of a structure constructed by a construction method according to an embodiment. [Figure 2] Figure 2(a) is a side view and a plan view of the precast member with scaffolding. [Figure 3] FIG. 3 is a side view showing a schematic view of a scaffold fixed to a precast member. [Figure 4] 4(a), 4(b), and 4(c) are side views schematically showing scaffolding according to modified examples. [Figure 5] FIG. 5 is a perspective view schematically showing a scaffolding according to a modified example. [Figure 6] 6(a) and 6(b) are diagrams illustrating steps of a construction method according to an embodiment. [Figure 7] 7(a), 7(b), and 7(c) are diagrams showing an example of steps of a construction method according to a modified example. [Figure 8] FIG. 8 is a diagram showing an example of steps of a construction method according to a modified example. [Figure 9] 9(a) and 9(b) are side views schematically showing a scaffolding according to a modified example. [Figure 10] 10(a) and 10(b) are cross-sectional views showing an example of a site to which a construction method according to a modified example is applied, and a comparative example, respectively. [Figure 11] FIG. 11 is a perspective view showing a precast member with scaffolding according to the second embodiment. [Figure 12] FIG. 12 is a plan view showing the precast member with scaffolding of FIG. [Figure 13] Figures 13(a) and 13(b) are plan views for explaining the steps of the construction method according to the second embodiment, and Figure 13(c) is a diagram showing a modified example of a joint reinforcing bar. [Figure 14] 14(a) and 14(b) are plan views for explaining steps of the construction method according to the second embodiment. [Figure 15] 15(a) and 15(b) are plan views for explaining steps of the construction method according to the second embodiment. [Figure 16] FIG. 16 is a plan view showing the protrusions, joint reinforcing bars, and formwork of the scaffolding-attached precast member according to the second embodiment. [Figure 17]FIG. 17 is a side view schematically showing a precast member with scaffolding according to a reference example. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, an embodiment of the construction method according to the present disclosure will be described with reference to the drawings. In the description of the drawings, the same or corresponding elements are designated by the same reference numerals, and duplicate explanations will be omitted as appropriate. The drawings may be partially simplified or exaggerated for ease of understanding, and the dimensional ratios and the like are not limited to those shown in the drawings.

[0023] (First embodiment) FIG. 1 is a side view showing an example of a structure 1. As shown in FIG. 1, the structure 1 is a concrete structure having a footing. That is, the structure 1 has a column portion 2 extending in a first direction D1 and an extension portion 3 extending from the lower end of the column portion 2. However, the shape of the structure is not limited to the shape of the structure 1 and can be changed as appropriate. In this embodiment, the first direction D1 is the vertical direction.

[0024] Fig. 2(a) is a side view showing a scaffold-equipped precast member 10 according to the embodiment. Fig. 2(b) is a plan view showing a scaffold-equipped precast member 10. As shown in Figs. 1, 2(a) and 2(b), the structure 1 is constructed by joining a plurality of scaffold-equipped precast members 10 (precast members 11) together.

[0025] The precast member with scaffolding 10 has a precast (PCa) structure with integrated scaffolding. The precast member with scaffolding 10 includes a precast member 11 that is part of the structure 1, and a scaffolding 20 fixed to the precast member 11 so as to protrude from the precast member 11.

[0026] In this embodiment, the precast member 11 is a half precast member of the structure 1. In plan view (when viewed along the first direction D1), the precast member 11 is frame-shaped with a concrete pouring space 11b inside. In this case, the precast member 11 can function as an embedded formwork. The precast member 11 has a concrete block 11c that is frame-shaped in plan view, and a plurality of reinforcing bars 11d at least partially embedded in the concrete block 11c. In the drawings, to avoid complexity, the reinforcing bars 11d are shown with solid lines and some hatching is omitted in the cross section.

[0027] The plurality of reinforcing bars 11d include a plurality of first reinforcing bars 11f extending in a second direction D2 that intersects (for example, orthogonal to) the first direction D1, a plurality of second reinforcing bars 11g extending in a third direction D3 that intersects both the first direction D1 and the second direction D2, and hoops 11h that are frame-shaped in a plan view. In this embodiment, the second direction D2 is the longitudinal direction of the precast member 11 in a plan view, and the third direction D3 is the lateral direction of the precast member 11 in a plan view.

[0028] The ends of the first reinforcing bars 11f are embedded in the concrete block 11c, and the remaining portions of the first reinforcing bars 11f are exposed in the concrete pouring space 11b. The first reinforcing bars 11f each have an anchor 11j at one end and the other end. For example, the multiple first reinforcing bars 11f are aligned along the third direction D3. The multiple first reinforcing bars 11f may also be aligned along the first direction D1.

[0029] The end of the second reinforcing bar 11g is embedded in the concrete block 11c, and the remaining portion of the second reinforcing bar 11g is exposed in the concrete pouring space 11b. The second reinforcing bar 11g has anchors 11k at both ends. For example, the multiple second reinforcing bars 11g are aligned along the second direction D2. The multiple second reinforcing bars 11g may also be aligned along the first direction D1. For example, the precast member 11 has multiple ties 11h aligned along the first direction D1. The number of ties 11h aligned along the first direction D1 is, for example, three. However, the number of ties 11h aligned along the first direction D1 is not particularly limited.

[0030] The precast member 11 has a hole 11p through which the main reinforcing bars of the structure 1 are passed. The hole 11p penetrates the precast member 11 in the first direction D1. The hole 11p is, for example, a sheath pipe buried in a concrete block 11c. In this case, the sheath pipe has irregularities that protrude inside and outside the sheath pipe.

[0031] The hole 11p does not have to be a sheath tube, but may be a through-hole in a concrete block 11c whose inner surface has been roughened. When the hole 11p is a sheath tube having irregularities or a through-hole whose inner surface has been roughened, it is possible to ensure the integrity of the inner surface of the hole 11p and the grout material filled in the hole 11p.

[0032] For example, the holes 11p are formed between the inner surface 11q that defines the concrete pouring space 11b and the hoops 11h in a plan view. For example, the precast member 11 has a plurality of holes 11p. In this case, the holes 11p are arranged at the four corners of the precast member 11, for example.

[0033] As an example, the plurality of holes 11p are arranged to form a rectangle in a plan view. The plurality of holes 11p may also be arranged to form a frame in a plan view. In this case, the plurality of holes 11p are aligned along the second direction D2, and the plurality of holes 11p are aligned along the third direction D3. As an example, the number of holes 11p aligned along the second direction D2 and the number of holes 11p aligned along the third direction D3 is four.

[0034] The concrete block 11c has a top surface 11r extending in the second direction D2 and the third direction D3, and a plurality of side surfaces 11v facing in a direction different from the top surface 11r. The plurality of side surfaces 11v include a first side surface 11s extending in the first direction D1 and the second direction D2, and a second side surface 11t extending in the first direction D1 and the third direction D3.

[0035] The first side surface 11s and the second side surface 11t are located outside the top surface 11r in a plan view. The concrete block 11c has a pair of first side surfaces 11s and a pair of second side surfaces 11t. The pair of first side surfaces 11s is aligned along the third direction D3, and the pair of second side surfaces 11t is aligned along the second direction D2.

[0036] In a plan view, the scaffolding 20 is fixed to the precast member 11 so as to surround the precast member 11. The scaffolding 20 is fixed to the precast member 11 so as to protrude from the precast member 11. "Fixing the scaffolding to the precast member so as to protrude from the precast member" indicates, for example, that no gap is formed between the precast member and the scaffolding. In other words, because the scaffolding protrudes from the precast member, no gap is formed between the scaffolding and the precast member. In this case, the scaffold is in contact with the precast member.

[0037] The scaffolding 20 is fixed to the precast member 11 so as to protrude from the side surface 11v in a plan view. For example, the scaffolding 20 is fixed to each of the first side surface 11s and the second side surface 11t. However, the scaffolding 20 may be fixed to only one of the first side surface 11s and the second side surface 11t.

[0038] Next, an example of the scaffolding 20 and a structure for fixing the scaffolding 20 to the precast member 11 will be described with reference to Fig. 3. The scaffolding 20 is detachable from the precast member 11. As shown in Fig. 3, the scaffolding 20 has scaffolding materials 21 fixed to the precast member 11.

[0039] Fig. 3 illustrates one scaffolding member 21. However, the scaffolding 20 includes a plurality of scaffolding members 21, which are arranged in a direction perpendicular to the plane of the paper in Fig. 3. The scaffolding member 21 has a contact portion 21b that contacts the precast member 11, a protruding portion 21c that extends from the contact portion 21b in the opposite direction to the precast member 11, and an inclined portion 21d that extends diagonally downward from the protruding portion 21c toward the contact portion 21b.

[0040] The contact portion 21b extends, for example, along the side surface 11v of the precast member 11 and is in surface contact with the side surface 11v. This eliminates any gap between the scaffolding 20 and the precast member 11. A bolt 11w protruding from the side surface 11v is embedded in the precast member 11, and the contact portion 21b has a through hole 21f through which the bolt 11w passes. The bolt 11w protruding from the side surface 11v is passed through the through hole 21f, and a nut 21g is fastened to the bolt 11w, thereby fixing the scaffolding material 21 to the precast member 11. For example, the precast member 11 has a plurality of bolts 11w aligned along the first direction D1, and the scaffolding material 21 has a plurality of through holes 21f aligned along the first direction D1.

[0041] The protruding portion 21c extends horizontally. For example, the inclined portion 21d is welded and fixed to the end of the protruding portion 21c opposite the contact portion 21b and to the lower portion of the contact portion 21b. The scaffolding 20 has, for example, a scaffolding board 22 that is placed on the protruding portion 21c. The scaffolding board 22 has a plurality of claw portions 22b that hook onto the edge of the protruding portion 21c, and the scaffolding board 22 is fixed to the protruding portion 21c by the plurality of claw portions 22b hooking onto the protruding portion 21c.

[0042] The above describes an example of the configuration of the scaffolding 20 fixed to the precast member 11. However, the configuration of the scaffolding 20 is not limited to the above example and can be modified as appropriate. Furthermore, the scaffolding material 21 may have a structure similar to the waling bracket of an earth retaining wall made by combining angle irons, or may be a commercially available scaffolding material. In this way, various types of scaffolding 20 can be used.

[0043] Next, a scaffolding according to a modified example will be described with reference to Figures 4(a), 4(b), and 4(c). In the following, explanations that overlap with the explanation of the scaffolding 20 described above will be omitted as appropriate by assigning the same reference numerals. As shown in Figure 4(a), the scaffolding 20A according to the modified example has horizontal batten members 23.

[0044] The scaffolding 20A has a scaffolding material 21A having a different shape from the scaffolding material 21. The scaffolding material 21A has an extending portion 21h that protrudes from the precast member 11 and extends horizontally, a first plate portion 21j that extends downward from the extending portion 21h, and a second plate portion 21k that extends downward from the extending portion 21h between the precast member 11 and the first plate portion 21j. For example, the length in the first direction D1 of the first plate portion 21j is longer than the length in the first direction D1 of the second plate portion 21k.

[0045] The extension portion 21h is in contact with the side surface 11v of the precast member 11. This eliminates the gap between the scaffolding 20A and the precast member 11. An inclined portion 21d extending diagonally downward from the extension portion 21h is welded and fixed to the end of the extension portion 21h opposite the precast member 11 and to the lower part of the first plate portion 21j.

[0046] The scaffolding material 21A has an insertion space 21p into which a portion of the horizontal batten material 23 fits. The insertion space 21p is formed between the first plate portion 21j and the second plate portion 21k. The horizontal batten material 23 is, for example, an H-shaped steel. In this case, the horizontal batten material 23 has a pair of flanges 23b and a web 23c that connects the pair of flanges 23b to each other.

[0047] The horizontal batten material 23 is arranged so that one of a pair of flanges 23b enters the insertion space 21p and the other of the pair of flanges 23b contacts the side surface 11v of the precast member 11. The flange 23b has a through hole through which a bolt 11w protruding from the side surface 11v is passed. With the bolt 11w passed through the through hole, a nut 21g is fastened to the bolt 11w, thereby fixing the horizontal batten material 23 to the precast member 11. For example, the horizontal batten material 23 has a plurality of such through holes aligned along the first direction D1.

[0048] First plate portion 21j has a through hole through which bolt 21q is passed, and second plate portion 21k has a through hole through which bolt 21q is passed. Flange 23b has a through hole through which bolt 21q is passed. By fastening nuts 21t to bolts 21q passed through these through holes, horizontal batten material 23 is fixed to scaffolding material 21A.

[0049] The first plate portion 21j has a through hole through which the bolt 21v is passed, and the flange 23b has a through hole through which the bolt 21v is passed. By fastening the nut 21x to the bolt 21v passed through these through holes, the horizontal batten material 23 is more firmly fixed to the scaffolding material 21A.

[0050] FIG. 4(b) shows a modified example different from FIG. 4(a). In the following explanation, explanations that overlap with those of FIG. 4(a) above will be omitted as appropriate by assigning the same reference numerals. As shown in FIG. 4(b), a scaffolding 20B according to the modified example has a scaffolding material 21B and a horizontal batten material 23B. The scaffolding material 21B has a tension portion 21y extending from the first plate portion 21j to the side surface 11v of the precast member 11 instead of the bolt 21v and through hole. The tension portion 21y is in contact with the side surface 11v. The horizontal batten material 23B is a C-shaped steel. For example, the horizontal batten material 23B differs from the above-described horizontal batten material 23 in that the flange 23b does not have a portion that protrudes downward from the web 23c.

[0051] Figure 4(c) shows a modified example different from Figures 4(a) and 4(b). As shown in Figure 4(c), scaffolding 20C according to the modified example has scaffolding material 21C and horizontal batten material 23C. Scaffolding material 21C differs from scaffolding material 21B described above in that second plate portion 21k contacts side surface 11v of precast member 11.

[0052] The horizontal batten material 23C is a plurality of single pipes 23h. The plurality of single pipes 23h are lined up along the first direction D1. For example, bolts 21q are passed between the plurality of single pipes 23h, and the plurality of single pipes 23h are fixed to the scaffolding material 21 by fastening nuts to the bolts 21q passed through the through holes and between the plurality of single pipes 23h.

[0053] Fig. 5 is a diagram showing a scaffolding 20D according to a modified example. As shown in Fig. 5, on the scaffolding 20D, for example, work is performed to pour concrete into the concrete pouring space 11b of the precast member 11 in a plan view. As an example, a worker M holds a pouring hose H in his hand and pours concrete from the pouring hose H into the concrete pouring space 11b of the precast member 11.

[0054] In addition to the scaffolding members 21C and the horizontal batten members 23C, the scaffolding 20D further includes a plurality of struts 24. Each of the plurality of struts 24 is fixed to the protruding portion 21c of each scaffolding member 21C via a fixing member 25. By including a plurality of struts 24 in the scaffolding 20D, the stability of the scaffolding 20D can be further increased. The plurality of struts 24 extend vertically upward from the ground. The scaffolding 20D has a plurality of horizontal members 26 that connect the plurality of struts 24 to each other in the horizontal direction. The plurality of horizontal members 26 are lined up along the first direction D1.

[0055] Next, an example of the steps of the construction method according to this embodiment will be described. An example of a method for constructing the above-mentioned structure 1 using the scaffolding-attached precast member 10 will be described below. First, as shown in FIG. 6(a), a surface member 30 is fabricated (a step of fabricating a surface member). The surface member 30 is a member that will become the extension portion 3 of the structure 1.

[0056] The surface member 30 has a concrete portion 31 and a plurality of main reinforcing bars 32 protruding from the concrete portion 31. More specifically, the concrete portion 31 has a rectangular plate shape, and the plurality of main reinforcing bars 32 protrude from a main surface 31b located at one end of the concrete portion 31 in the plate thickness direction. The main reinforcing bars 32 are the main reinforcing bars of the structure 1.

[0057] The main reinforcing bars 32 have anchoring portions 32b located inside the concrete portion 31. The anchoring portions 32b extend inside the concrete portion 31 in a direction bent relative to the direction in which the main reinforcing bars 32 protrude from the concrete portion 31. The anchoring portions 32b are, for example, portions bent into an L-shape inside the concrete portion 31.

[0058] 6(a), the anchoring portions 32b of the two main reinforcing bars 32 located in the center in the left-right direction are bent in a direction perpendicular to the plane of the page. The surface member 30 configured as described above is produced by arranging multiple main reinforcing bars 32 with anchoring portions 32b inside a formwork, and pouring concrete to become the concrete portion 31 inside the formwork.

[0059] Furthermore, separate from the production of the surface member 30, as shown in Figures 2(a) and 2(b), a scaffolding 20 is fixed to the precast member 11 to produce a precast member 10 with a scaffolding (a step of producing a precast member with a scaffolding). More specifically, a precast member 11 is produced (a step of producing a precast member).

[0060] Next, the scaffolding 20 is fixed to the precast member 11 (step of fixing the scaffolding). The scaffolding 20 is fixed to the precast member 11 by assembling it on the ground. For example, as shown in FIG. 3, the scaffolding material 21 is fixed to the precast member 11 by tightening a nut 21g onto a bolt 11w with the contact portion 21b of the scaffolding material 21 in contact with the side surface 11v of the precast member 11. Then, a scaffolding board 22 is fixed to the protruding portion 21c of the scaffolding material 21, thereby completing the production of the precast member 10 with the scaffolding. At this time, a plurality of precast members 10 with the scaffolding are produced in advance.

[0061] Then, as shown in Figure 6(b), the plurality of scaffolding-equipped precast members 10 are joined together to construct the structure 1 (process of constructing a structure). At this time, the plurality of scaffolding-equipped precast members 10 are stacked along the first direction D1 to construct the structure 1. More specifically, the scaffolding-equipped precast members 10 are lifted by a lifting machine such as a crane, and the plurality of main reinforcing bars 32 are passed from below through the plurality of holes 11p, thereby stacking the scaffolding-equipped precast members 10 on the surface members 30 (process of stacking the scaffolding-equipped precast members on the surface members).

[0062] Then, another scaffold-attached precast member 10 is lifted by a crane, and multiple main reinforcing bars 32 are passed from below through multiple holes 11p in the scaffold-attached precast member 10, thereby stacking the scaffold-attached precast members 10 (step of stacking scaffold-attached precast members). After the main reinforcing bars 32 have been inserted into the holes 11p, the holes 11p are filled with a filler material. The filler material is, for example, grout. The filler material is filled into the multiple holes 11p from vertically above, for example.

[0063] For example, a worker may stand on the scaffolding 20 of the lower of the pair of upper and lower scaffolding-equipped precast members 10, and apply adhesive between the pair of upper and lower precast members 11. In this way, the worker can stand on the scaffolding 20 and perform various tasks.

[0064] A plurality of scaffolding-equipped precast members 10 are stacked on the surface member 30, and after the stacking of the scaffolding-equipped precast members 10 is completed, concrete is poured, for example, into the concrete pouring spaces 11b of the plurality of precast members 11 in a plan view (concrete pouring process). In this way, concrete is poured into the concrete pouring spaces 11b of the precast members 11 after the scaffolding-equipped precast members 10 are stacked on the surface member 30. This prevents the scaffolding-equipped precast members 10 from becoming too heavy before stacking, thereby preventing restrictions on lifting the scaffolding-equipped precast members 10 by a crane. After concrete is poured into the concrete pouring spaces 11b of the plurality of precast members 11, the construction of the structure 1 is completed.

[0065] After construction of the structure 1 is completed, the scaffolding 20 is removed from the precast members 11 (scaffolding removal process). At this time, the scaffolding 20 is removed in order, starting with the scaffolding-attached precast member 10 located vertically above. As a specific example, when N layers (N is a natural number) of scaffolding-attached precast members 10 are stacked, a worker first stands on the scaffolding 20 of the (N-1)th scaffolding-attached precast member 10 from the bottom, and then removes the scaffolding 20 from the Nth scaffolding-attached precast member 10 from the bottom. Note that when the scaffolding 20 is removed, holes for the bolts 11w remain in the precast members 11, and these holes are filled with hole-filling material.

[0066] Next, a worker stands on the scaffolding 20 of the (N-2)th precast member with scaffolding 10 from the bottom, and removes the scaffolding 20 of the (N-1)th precast member with scaffolding 10 from the bottom. This process of removing the scaffolding 20 is repeated until the scaffolding 20 of the lowest precast member with scaffolding 10 is finally removed, completing the series of steps in the method for constructing the structure 1 according to this embodiment.

[0067] As described above, in the construction method according to this embodiment, a plurality of precast members 10 with scaffoldings are joined together to construct the structure 1, and each precast member 10 with scaffoldings comprises a precast member 11 that becomes part of the structure 1 and scaffolding 20. In each precast member 10 with scaffoldings, the scaffoldings 20 are fixed to the precast member 11 so as to protrude from the precast member 11. By fixing the scaffoldings 20 so as to protrude from the precast member 11 that becomes part of the structure 1, gaps formed between the scaffoldings 20 and the structure 1 can be eliminated.

[0068] This prevents people from falling through gaps formed between the scaffolding 20 and the structure 1, thereby preventing people from falling when constructing the structure 1. Furthermore, because the precast members 11 of each scaffold-attached precast member 10 become part of the structure 1, it is not necessary to install and remove formwork for constructing the structure 1. Furthermore, because the scaffolding 20 is fixed to the precast members 11 in advance, it is not necessary to assemble the scaffolding 20 at high altitudes. This reduces the amount of work required for working at high altitudes, contributing to improved safety.

[0069] In this embodiment, in the process of constructing the structure 1, a plurality of scaffolding-attached precast members 10 are stacked along the vertical direction (first direction D1) to construct the structure 1. In this case, the scaffolding-attached precast members 10 are stacked along the vertical direction to construct the structure 1. This makes it possible to prevent gaps from occurring between the scaffolding 20 and the structure 1 in each of the stacked scaffolding-attached precast members 10, thereby more reliably preventing falls and reducing the amount of work required at height.

[0070] The construction method according to this embodiment includes a step of removing the scaffolding 20 from the precast members 11 after constructing the structure 1. In this case, the scaffolding 20 removed from the precast members 11 can be repurposed by fixing it to another precast member 11.

[0071] In this embodiment, in the step of removing the scaffolding 20, the scaffolding 20 may be removed in order starting from the scaffold-attached precast member 10 located vertically above. In this case, the scaffolding 20 is removed in order starting from the scaffold-attached precast member 10 located vertically above. Therefore, a worker on the scaffolding 20 of a scaffold-attached precast member 10 can remove the scaffolding 20 of the scaffold-attached precast member 10 above him, while removing the scaffolding 20 of the scaffold-attached precast member 10 above him, and so on, sequentially from the top. Therefore, the work of removing the scaffolding 20 can be performed efficiently.

[0072] In this embodiment, the precast members 11 have holes 11p through which the main reinforcing bars 32 of the structure 1 are passed. In this case, when multiple precast members 10 with scaffolding are joined, the main reinforcing bars 32 of the structure 1 are passed through the holes 11p of each precast member 11, thereby enabling the structure 1 to be constructed efficiently.

[0073] Next, a modified example of the construction method according to the modified example will be described. Some steps of the construction method according to the modified example below are the same as some steps of the construction method described above. Therefore, in the following explanation, explanations that overlap with steps of the construction method described above will be omitted as appropriate. Figure 7(a) is a diagram showing a plane member 30A that serves as an extension part of the structure according to the modified example.

[0074] As shown in Figure 7(a), a surface member 30A is fabricated (a process for fabricating a surface member). The surface member 30A differs from the surface member 30 described above in that the concrete portion 31A has insertion holes 31c into which main reinforcing bars 32A (see Figure 7(c)), which will be described later, are inserted. The concrete portion 31A has a plurality of insertion holes 31c, each of which is recessed vertically downward from the main surface 31b of the concrete portion 31A.

[0075] Next, as shown in Figure 7(b), multiple scaffold-equipped precast members 10 are stacked along the first direction D1 to construct the structure 1A (process of constructing a structure). More specifically, the scaffold-equipped precast members 10 are lifted using a lifting machine such as a crane, and the scaffold-equipped precast members 10 are aligned with the surface member 30A so that the multiple hole portions 11p are positioned directly above the multiple insertion holes 31c of the surface member 30A. At this time, the scaffold-equipped precast members 10 are stacked on the surface member 30A with the hole portions 11p communicating with the insertion holes 31c along the first direction D1, and further scaffold-equipped precast members 10 are stacked on top of the stacked scaffold-equipped precast members 10.

[0076] 7(c), a main reinforcing bar 32A with a mechanical anchor 33 attached thereto is prepared (a process of preparing a main reinforcing bar). The main reinforcing bar 32A with the mechanical anchor 33 attached thereto is inserted into the hole 11p and the insertion hole 31c (a process of inserting the mechanical anchor into the insertion hole). Then, the mechanical anchor 33 is embedded in the insertion hole 31c (a process of embedding the mechanical anchor).

[0077] In the process of embedding the mechanical anchor, for example, an injection hole 31f is formed extending from the insertion hole 31c to the side surface 31d of the concrete portion 31A, and a filler material is injected into the insertion hole 31c through the injection hole 31f. For example, the filler material is grout. For example, the injection hole 31f is a hose that is pre-embedded in the concrete portion 31A.

[0078] The filler injected into the insertion holes 31c fills the insertion holes 31c and the holes 11p. This filling continues until the filler reaches the top of the holes 11p. After this filling of the filler has been carried out on all of the insertion holes 31c and holes 11p, the series of steps in the construction method is completed.

[0079] The above describes an example in which main reinforcing bars 32A with attached mechanical anchors 33 are inserted into holes 11p and insertion holes 31c, and then mechanical anchors 33 are embedded in insertion holes 31c with filler. However, as shown in Figure 8, mechanical anchors 34 that fix main reinforcing bars 32A may be embedded in insertion holes 31c in advance (step of embedding mechanical anchors).

[0080] The mechanical anchors 34 have screw holes into which the main reinforcing bars 32A are screwed. For example, the mechanical anchors 34 are expanded anchors. After fabricating the surface member 30A with the mechanical anchors 34 pre-embedded, the scaffolding-attached precast member 10 is lifted as described above, and the scaffolding-attached precast member 10 is aligned with the surface member 30A so that the hole 11p is located directly above the insertion hole 31c, and then the scaffolding-attached precast member 10 is stacked on top of the surface member 30A. After placing the scaffolding-attached precast member 10 on top of the surface member 30A, the main reinforcing bars 32A are passed through the hole 11p and the insertion hole 31c.

[0081] The main reinforcing bars 32A passed through the holes 11p and the insertion holes 31c are fixed to the mechanical anchors 34. At this time, the main reinforcing bars 32A are screwed into the mechanical anchors 34 to fix the main reinforcing bars 32A to the mechanical anchors 34. Then, as described above, filler material is injected into the insertion holes 31c through the injection holes 31f, and the filler material is filled into all of the insertion holes 31c and holes 11p to construct the structure 1A. After that, the series of steps in the construction method is completed.

[0082] As described above, the construction method according to the modified example includes the steps of forming insertion holes 31c into the surface member 30A located below the scaffolding-attached precast member 10, into which the main reinforcing bars 32A of the structure 1A are inserted, and embedding mechanical anchors 34 into which the main reinforcing bars 32A are fixed. In the step of constructing the structure 1A, the scaffolding-attached precast member 10 is placed on top of the surface member 30A, and the main reinforcing bars 32A passed through the holes 11p and the insertion holes 31c are fixed to the mechanical anchors 34. This makes it easy to arrange and fix the main reinforcing bars 32A of the structure 1A, making it even easier to construct the structure 1A.

[0083] Next, a modified example of a precast member with a foothold 10A will be described with reference to Figures 9(a) and 9(b). As shown in Figures 9(a) and 9(b), the precast member with a foothold 10A has a foothold 40 that can be folded toward the precast member 11, instead of the foothold 20 described above.

[0084] The scaffolding 40 has a foldable scaffolding material 41. The scaffolding material 41 has a contact portion 41b that contacts the precast member 11, a protruding portion 41c that extends from the contact portion 41b in the opposite direction to the precast member 11, an inclined portion 41d that extends diagonally downward from the protruding portion 41c toward the contact portion 41b, and an erected portion 41f that extends vertically upward from the protruding portion 41c.

[0085] The scaffolding material 41 has a plurality of hinge portions 42. Each portion of the scaffolding material 41 is rotatable via the hinge portions 42. The hinge portions 42 are provided at the upper portion of the contact portion 41b and at the end of the protruding portion 41c on the contact portion 41b side. This allows the protruding portion 41c to rotate relative to the contact portion 41b.

[0086] Hinge portion 42 is provided at an overlapping portion of inclined portion 41d with contact portion 41b, an overlapping portion of inclined portion 41d with protruding portion 41c, and a central portion of inclined portion 41d. This allows inclined portion 41d to bend around hinge portion 42 at its central portion and to rotate relative to contact portion 41b and protruding portion 41c. Hinge portion 42 is provided at an end of protruding portion 41c on the side of standing portion 41f and an end of standing portion 41f on the side of protruding portion 41c. This allows standing portion 41f to rotate relative to protruding portion 41c.

[0087] 9(a) , the scaffolding material 41 is foldable by having multiple hinge portions 42. At this time, the protruding portion 41c is folded toward the contacting portion 41b, the inclined portion 41d is bent and folded between the contacting portion 41b and the inclined portion 41d, and the standing portion 41f is folded toward the protruding portion 41c. Each portion of the folded scaffolding material 41 is fixed by, for example, a pin to prevent it from unfolding unintentionally.

[0088] 9(b), the scaffolding material 41 can be unfolded. At this time, the erected portion 41f moves away from the protruding portion 41c, the protruding portion 41c moves away from the contact portion 41b, and the inclined portion 41d is unfolded. In this state, each hinge portion 42 is fixed by a pin, for example, to prevent each portion of the scaffolding material 41 from unintentionally folding or bending.

[0089] As described above, in the scaffolding-equipped precast member 10A, the scaffolding 40 can be folded toward the precast member 11. Therefore, when lifting the scaffolding-equipped precast member 10A, for example, the scaffolding 40 can be folded so that the scaffolding 40 protruding from the precast member 11 does not get in the way. Furthermore, by folding the scaffolding 40 and lifting the scaffolding-equipped precast member 10A, for example, structures can be constructed efficiently even in narrow construction sites.

[0090] The above describes embodiments and various modifications of the method for constructing a structure according to the present disclosure. However, the method for constructing a structure according to the present disclosure is not limited to the contents of the above-described embodiments or modifications, and may be further modified within the scope of the gist described in the claims. In other words, the shape, size, material, number, and arrangement of each part of the structure according to the present disclosure, as well as the content and order of the steps of the method for constructing a structure, can be modified as appropriate within the scope of the gist described above.

[0091] Figure 10(a) is a diagram showing a site A1 where a box culvert 1B, a type of structure, is constructed using the scaffolding-equipped precast member 10 described above. Figure 10(b) is a diagram showing a site A2 where the box culvert 1B is constructed using conventional scaffolding 100. At sites A1 and A2, cut-and-cover work and construction of the box culvert 1B are carried out.

[0092] When conventional scaffolding 100 is used, a gap S occurs between the structure 1C and the scaffolding 100. The width of the gap S is approximately 500 mm. In contrast, when the precast member with scaffolding 10 is used, the gap S can be eliminated, thereby reducing the number of construction projects. For example, at the site A1 where the precast member with scaffolding 10 is used, the excavation width W of the ground G can be reduced by eliminating the gap S.

[0093] As a result, the amount of construction work required can be reduced, including the amount of excavated soil, crushed stone for the foundation, leveling concrete, and the amount of backfill soil after construction. In the case of a strut-type retaining wall, the length of the strut can be reduced by about 1 meter, and it is also possible to reduce the number of intermediate piles. Furthermore, if the excavation width W is not narrowed at site A1 using precast members 10 with scaffolding, there is more space between the main body 1C and the retaining wall 1D than at site A2 using scaffolding 100, making it possible to create a wider safety passageway, for example.

[0094] In the above-described embodiment, a structure 1 and a construction method were described that include precast members 11, which are half precast members. However, a structure and a construction method that include precast members, which are full precast members, may also be used. Furthermore, in the above-described embodiment, an example was described in which the precast members 11 are frame-shaped with a concrete pouring space 11b. However, the precast members may be flat or circular. For example, when flat plates are used on the wall surface, the gable portion may be a formwork or structural joint made of plywood or the like. In this way, the shape of the precast members can be changed as appropriate.

[0095] In the above-described embodiment, an example was described in which a structure 1 was constructed by stacking multiple precast members with scaffolding 10 in the vertical direction. However, a structure may also be constructed by arranging multiple precast members with scaffolding in the horizontal direction. In this way, the direction in which the precast members with scaffolding are arranged can be changed as appropriate.

[0096] (Second embodiment) As described above, a structure may be constructed by arranging multiple precast members with scaffoldings horizontally. FIG. 17 shows multiple precast members with scaffoldings 50 arranged horizontally in the arranging direction D4. As shown in FIG. 17, the precast member with scaffoldings 50 includes a precast member 51 having a concrete block 51c and multiple reinforcing bars 51d at least partially embedded in the concrete block 51c, and the scaffolding 20 described above. The ends of the reinforcing bars 51d in the arranging direction D4 protrude from the concrete block 51c.

[0097] When joining multiple scaffolding-equipped precast members 50 arranged along the parallel installation direction D4, the reinforcing bars 51d protruding from each concrete block 51c are connected to each other by joints 52 (e.g., mechanical joints). Then, formwork is assembled in the joints 51h between the multiple precast members 51, and filling concrete is poured into them.

[0098] However, when erecting and joining multiple scaffolding-attached precast members 50 using this method, discontinuities in the scaffolding 20 may occur in the gap sections. In this case, it becomes necessary to install scaffolding on the scaffolding 20 to bridge the discontinuities between the multiple scaffolding-attached precast members 50, which may pose a risk of falling from the scaffolding 20 during the installation work. Furthermore, for example, if the diameter of the joint 52 is large, the joint 52 will be long and the width of the gap section will be large, which may result in a problem of a large amount of formwork being assembled in the joint 51h. Therefore, a construction method is needed that can reduce the discontinuities in the scaffolding and the amount of formwork assembled.

[0099] Fig. 11 is a perspective view showing a precast member 60 with scaffolding according to the second embodiment. Fig. 12 is a plan view showing the precast member 60 with scaffolding. In Fig. 12, for ease of illustration, reinforcing bars embedded in the concrete blocks are shown with solid lines. As shown in Figs. 11 and 12, the precast member 60 with scaffolding includes a precast member 61 having concrete blocks 61c and reinforcing bars 61d, and the scaffolding 20 described above.

[0100] The concrete block 61c has, for example, an upper surface 61f, a first side surface 61h extending in the arrangement direction D4 of the scaffolding-attached precast member 60 and in the vertical direction D6, and a second side surface 61j extending in the orthogonal direction D5, which is a horizontal direction perpendicular to the arrangement direction D4, and in the vertical direction D6. The scaffolding 20 is fixed to, for example, the first side surface 61h.

[0101] The scaffolding-equipped precast member 60 has a protruding portion 62A protruding from the end of the scaffolding-equipped precast member 60 in the arrangement direction D4. The protruding portion 62A protrudes, for example, from the second side surface 61j. The scaffolding-equipped precast member 60 has a plurality of protruding portions 62A aligned along the orthogonal direction D5 and spaces 62B formed between the plurality of protruding portions 62A. The spaces 62B are areas where concrete is poured.

[0102] For example, the scaffolding-equipped precast member 60 has multiple spaces 62B. The multiple spaces 62B are aligned along the juxtaposition direction D4. The spaces 62B are defined, for example, by the inner surface 62b of the protrusion 62A facing the center of the scaffolding-equipped precast member 60 in the orthogonal direction D5 and the second side surface 61j. For example, the space 62B is a recess recessed in the juxtaposition direction D4 between two protrusions 62A aligned along the orthogonal direction D5. As an example, the space 62B is a U-shaped recess.

[0103] The reinforcing bars 61d include, for example, horizontal reinforcing bars 63 extending along the parallel installation direction D4, shear reinforcement bars 64 extending along the orthogonal direction D5, and vertical reinforcing bars 65 extending along the vertical direction D6. For example, the reinforcing bars 61d include a plurality of horizontal reinforcing bars 63. The horizontal reinforcing bars 63 are aligned along the orthogonal direction D5.

[0104] The horizontal reinforcing bar 63 is embedded in the protruding portion 62A. That is, the horizontal reinforcing bar 63 is embedded in the concrete block 61c, and the end of the horizontal reinforcing bar 63 in the juxtaposition direction D4 is located inside the protruding portion 62A. The horizontal reinforcing bar 63 extends from one end to the other end of the scaffolding-equipped precast member 60 in the juxtaposition direction D4.

[0105] For example, the reinforcing bar 61d includes a plurality of shear reinforcement bars 64. The plurality of shear reinforcement bars 64 are arranged along the parallel installation direction D4. Some of the plurality of shear reinforcement bars 64 are embedded in the concrete block 61c, and the remaining portions of the plurality of shear reinforcement bars 64 are exposed to the space 62B. When viewed along the vertical direction D6 (plan view), the ends of the shear reinforcement bars 64 in the orthogonal direction D5 are embedded in the protruding portions 62A and intersect with the horizontal reinforcing bars 63. For example, the reinforcing bar 61d includes a plurality of vertical reinforcing bars 65. The vertical reinforcing bars 65 are arranged at the intersections of the horizontal reinforcing bars 63 and the shear reinforcement bars 64.

[0106] A method for constructing a structure according to the second embodiment will be described. First, as shown in Fig. 13(a), a joint reinforcing bar 66 is fixed to the shear reinforcement bar 64 protruding from the protruding portion 62A in the orthogonal direction D5 (step of fixing the joint reinforcing bar). The joint reinforcing bar 66 forms a gap lap joint with the horizontal reinforcing bar 63. This allows stress to be efficiently transmitted between the horizontal reinforcing bar 63 and the joint reinforcing bar 66.

[0107] 13(c), the joint reinforcing bar 66 may have at least one end processed. For example, the joint reinforcing bar 66 may be a joint reinforcing bar 66A with hooks on both ends, a joint reinforcing bar 66B with a hook on one end and a mechanical joint 66b on the other end, or a joint reinforcing bar 66C with a mechanical joint 66b on both ends. In this case, the required joint length can be shortened, and the length of the space 62B in the parallel installation direction D4 can be reduced.

[0108] The joint reinforcing bar 66 is arranged, for example, in one of a pair of spaces 62B aligned along the juxtaposition direction D4. The joint reinforcing bar 66 is fixed so as to extend in the juxtaposition direction D4 at a position adjacent to the protrusion 62A. A portion of the joint reinforcing bar 66 is aligned with a portion of the horizontal reinforcing bar 63 along the orthogonal direction D5.

[0109] For example, the joint reinforcing bars 66 are fixed to the shear reinforcement bars 64 with tie wires. However, the joint reinforcing bars 66 may also be fixed to the shear reinforcement bars 64 with clips. The length of the space 62B in the parallel installation direction D4 is set to a length that allows stress transmission by the joint reinforcing bars 66. The inside of the space 62B (inner surface 62b) may be roughened to improve integration with the concrete that will be poured later. The above steps are performed, for example, in a factory where the precast member 61 is manufactured.

[0110] A plurality of scaffolding-equipped precast members 60 are lined up along the juxtaposition direction D4 (step of arranging scaffolding-equipped precast members). At this time, the scaffolding-equipped precast members 60 are lined up so that the protruding portions 62A face other scaffolding-equipped precast members 60. A plurality of scaffolding-equipped precast members 60 are arranged so that the protruding portions 62A face each other along the juxtaposition direction D4.

[0111] When multiple scaffolding-equipped precast components 60 are arranged, for example, gaps 62c are formed between the multiple protrusions 62A. The length of the gaps 62c in the juxtaposition direction D4 is long enough to allow a hand to reach from the gap 62c into the space 62B. In this case, it is possible to reach into the space 62B from outside the pair of protrusions 62A aligned along the orthogonal direction D5. As an example, the length of the gaps 62c in the juxtaposition direction D4 is approximately 100 mm.

[0112] As shown in Figures 13(b) and 14(a), scaffolding members 67b and handrails 67c are installed between multiple scaffoldings 20 to connect the multiple scaffoldings 20 to each other (scaffolding connecting process). At this time, the handrails 27 that were at the ends of the scaffoldings 20 in the juxtaposition direction D4 are removed. The scaffolding members 67b are, for example, gap steps. The two scaffoldings 20 lined up along the juxtaposition direction D4 are connected to each other by the interposition of the scaffolding members 67b and handrails 67c between them.

[0113] 14(b) and 15(a), joint reinforcing bars 66 are placed so as to extend in the parallel installation direction D4 together with the horizontal reinforcing bars 63 (step of placing joint reinforcing bars). At this time, the fixed joint reinforcing bars 66 are removed from the shear reinforcement bars 64, and the joint reinforcing bars 66 are slid toward another precast member with scaffolding 60 (for example, the precast member with scaffolding 60 on the left) (sliding step).

[0114] For example, the joint reinforcing bar 66, which has been fixed to the shear reinforcement bar 64 with a tie or clip, is removed from the shear reinforcement bar 64, and the joint reinforcing bar 66 is slid to the center of the parallel installation direction D4 of the two spaces 62B aligned along the parallel installation direction D4. One of the pair of horizontal reinforcing bars 63 aligned along the parallel installation direction D4 and the joint reinforcing bar 66 are aligned along the orthogonal direction D5, and the other of the horizontal reinforcing bars 63 aligned along the parallel installation direction D4 and the joint reinforcing bar 66 are aligned along the orthogonal direction D5. By arranging the joint reinforcing bar 66 in this manner, the joint reinforcing bar 66 and the horizontal reinforcing bar 63 form a gap and a lap joint. The joint reinforcing bar 66 is then fixed to the shear reinforcement bar 64 with a tie or clip.

[0115] The sliding of the joint reinforcing bar 66 is performed, for example, by a worker inserting his / her hand M1 into the space 62B through the gap 62c. However, if the height of the precast member 61 is low, the above sliding may be performed by inserting his / her hand M1 into the space 62B from above. Alternatively, the above sliding may be performed by inserting a magic hand into the space 62B from above. In this case, the gap 62c can be eliminated.

[0116] 15(b), for example, formwork 68 is installed (formwork installation step). In this case, formwork 68 is placed at each end of the pair of gaps 62c aligned along the orthogonal direction D5. However, if the gaps 62c are not needed as described above, it is possible to omit the placement of formwork 68.

[0117] For example, as shown in Figures 15(b) and 16, an insert 69b (or a separator) may be embedded in a portion of a concrete block 61c where a form 68 is to be installed, and the form 68 may have a through-hole 68b. Then, the form 68 may be installed by threading a bolt 68c passed through the through-hole 68b into the insert 69b. In this case, the installation of the form 68 can be made less labor-intensive.

[0118] Next, concrete is poured into the space 62B where the joint reinforcing bars 66 are placed (concrete pouring process). After the concrete hardens, the formwork 68 is removed, and if an insert 69b is formed in the concrete block 61c, the insert 69b is filled with a filler material (e.g., mortar). Through these processes, the construction of the structure is completed.

[0119] As described above, in the construction method according to the second embodiment, the step of constructing a structure includes a step of arranging a plurality of scaffolding-equipped precast members 60 along the horizontal arranging direction D4. The scaffolding-equipped precast members 60 have protruding portions 62A that protrude from the ends of the scaffolding-equipped precast members 60 in the arranging direction D4 and have horizontal reinforcing bars 63 embedded therein that extend along the arranging direction D4. In the step of arranging the scaffolding-equipped precast members 60, the scaffolding-equipped precast members 60 are arranged so that the protruding portions 62A face other scaffolding-equipped precast members 60.

[0120] This construction method includes, after the step of arranging scaffolding-equipped precast members 60, the steps of arranging joint reinforcing bars 66 in spaces 62B aligned with the protruding parts 62A along orthogonal direction D5, which is a horizontal direction orthogonal to the arranging direction D4, so that the joint reinforcing bars 66 extend in the arranging direction D4 together with the horizontal reinforcing bars 63, and pouring concrete into the spaces 62B in which the joint reinforcing bars 66 have been arranged. In this case, the scaffolding-equipped precast members 60 have protruding parts 62A, and the scaffolding-equipped precast members 60 are arranged so that the protruding parts 62A face other scaffolding-equipped precast members 60 along the arranging direction D4.

[0121] By arranging the protrusions 62A so that they face other precast members with scaffolding 60, the distance between the multiple precast members with scaffolding 60 can be shortened, thereby reducing the gaps between the multiple precast members with scaffolding 60. This makes it possible to prevent people from falling through gaps formed between the multiple precast members with scaffolding 60, and also reduces the amount of formwork 68 required when pouring concrete between the multiple precast members with scaffolding 60.

[0122] Furthermore, in space 62B aligned with protrusion 62A along orthogonal direction D5, joint reinforcing bars 66 are arranged so as to extend in juxtaposition direction D4 together with horizontal reinforcing bars 63, and concrete is poured into space 62B. By arranging joint reinforcing bars 66 so as to be aligned with horizontal reinforcing bars 63 along orthogonal direction D5, gap lap joints can be provided between multiple scaffolding-equipped precast members 60, and stress can be appropriately transmitted between multiple scaffolding-equipped precast members 60.

[0123] In this embodiment, the scaffolding-equipped precast member 60 has a plurality of protrusions 62A aligned along the orthogonal direction D5 and spaces 62B formed between the plurality of protrusions 62 A. In this case, by forming the spaces 62B between the plurality of protrusions 62A aligned along the orthogonal direction D5, it is possible to further reduce the gaps between the plurality of scaffolding-equipped precast members 60 and further reduce the amount of formwork 68 required when pouring concrete into the spaces 62B.

[0124] In this embodiment, in the step of arranging the scaffolding-equipped precast members 60, the scaffolding-equipped precast members 60 may be arranged so that the protruding portions 62A face each other along the arranging direction D4, and gaps 62c may be formed between the protruding portions 62A. In this case, the joint reinforcing bars 66 can be easily arranged by inserting a hand M1 or the like through the gaps 62c.

[0125] In this embodiment, the construction method according to the second embodiment includes a step of fixing a joint reinforcing bar 66 to a shear reinforcement bar 64 protruding from the protruding portion 62A in the orthogonal direction D5. The step of placing the joint reinforcing bar 66 includes a step of removing the joint reinforcing bar 66 fixed in the fixing step from the shear reinforcement bar 64 and sliding the joint reinforcing bar 66 toward another precast member with scaffolding 60. In this case, the joint reinforcing bar 66 can be fixed to the shear reinforcement bar 64 of the precast member with scaffolding 60 in advance. Furthermore, by removing the joint reinforcing bar 66 from the shear reinforcement bar 64 and sliding it, the placement of the joint reinforcing bar 66 can be easily performed.

[0126] The construction method according to the second embodiment has been described above. However, it is possible to further modify the construction method according to the second embodiment. For example, in the second embodiment, the space 62B is described as a U-shaped recess located between two protrusions 62A. However, the space does not have to be a U-shaped recess. For example, the space may be L-shaped defined by one protrusion 62A and the second side surface 61j. Furthermore, the horizontal reinforcing bar 63 may protrude from the second side surface 61j in the juxtaposition direction D4.

[0127] In this way, it is possible to appropriately change the shape of the space, the number of protrusions 62A, and the arrangement of the horizontal reinforcing bars 63. In the second embodiment, too, the shape, size, material, number, and arrangement of each part of the structure, as well as the content and order of the steps in the construction method, can be appropriately changed within the scope of the gist described in the claims. [Explanation of symbols]

[0128] 1,1A...structure, 1B...box culvert, 1C...body, 1D...retaining wall, 2...column, 3...extension, 10,10A...precast member with scaffolding, 11...precast member, 11b...concrete pouring space, 11c...concrete block, 11d...reinforcing bar, 11f...first reinforcing bar, 11g...second reinforcing bar, 11h...hoop, 11j,11k...anchoring body, 11p...hole, 11q...inner surface, 11r...top surface, 11s...first side, 11t...second side, 11v...side, 11w...bolt, 20,20A,20B,20C,20D...scaffolding, 21,21A,21B, 21C... scaffolding material, 21b... contact portion, 21c... protruding portion, 21d... inclined portion, 21f... through hole, 21g... nut, 21h... extension portion, 21j... first plate portion, 21k... second plate portion, 21p... insertion space, 21q... bolt, 21t... nut, 21v... bolt, 21x... nut, 21y... tension portion, 21z... nut, 22... scaffolding board, 22b... claw portion, 23, 23B, 23C... horizontal batten material, 23b... flange, 23c... web, 23h... single pipe, 24... support, 25... fixing member, 26... horizontal member, 30, 30A... surface member, 31, 31A... concrete portion, 31b... main surface , 31c...insertion hole, 31d...side surface, 31f...injection hole, 32, 32A...main rebar, 32b...anchoring portion, 33, 34...mechanical anchoring body, 40...scaffolding, 41...scaffolding material, 41b...contact portion, 41c...protruding portion, 41d...inclined portion, 41f...standing portion, 42...hinge portion, 50...precast member with scaffolding, 51...precast member, 51c...concrete block, 51d...rebar, 51h...joint, 52...joint, 60...precast member with scaffolding, 61...precast member, 61c...concrete block, 61d...rebar, 61f...top surface, 61h...first side surface, 61 j...second side, 62A...protrusion, 62B...space, 62b...inner surface, 62c...gap, 63...horizontal reinforcing bar, 64...shear reinforcement, 65...vertical reinforcing bar, 66, 66A, 66B, 66C...joint reinforcing bar, 66b...mechanical joint, 67b...scaffolding component, 67c...handrail, 68...formwork, 68b...through hole, 68c...bolt, 69b...insert, 100...scaffolding, A1, A2...site, D1...first direction, D2...second direction, D3...third direction, D4...parallel direction, D5...orthogonal direction, D6...vertical direction, G...ground, H...pouring hose, M...worker, M1...hand, S...gap, W...excavation width.

Claims

1. A construction method for constructing a structure, comprising: a step of fixing a scaffold to a precast member that will become a part of the structure so that the scaffold protrudes from the precast member to produce a precast member with a scaffold; Joining a plurality of the precast members with scaffolding together to construct the structure; Equipped with How to build it.

2. In the step of constructing the structure, the plurality of precast members with scaffolding are stacked in a vertical direction to construct the structure. The method of claim 1.

3. and removing the scaffolding from the precast members after the structure has been constructed. The construction method according to claim 1 or claim 2.

4. In the step of constructing the structure, the plurality of precast members with scaffolding are stacked in a vertical direction to construct the structure; In the step of removing the scaffolding, the scaffolding is removed in order from the precast member with the scaffolding located vertically above. The construction method of claim 3.

5. The scaffolding is foldable toward the precast member. The construction method according to claim 1 or claim 2.

6. The precast member has holes through which main reinforcing bars of the structure are passed. The construction method according to claim 1 or claim 2.

7. forming an insertion hole into which a main reinforcing bar of the structure is inserted in a surface member located below the scaffolding-attached precast member, and embedding a mechanical anchor into the insertion hole to fix the main reinforcing bar; In the step of constructing the structure, the precast member with scaffolding is placed on the surface member, and the main reinforcing bars that have been passed through the hole portions and the insertion holes are fixed to the mechanical anchors. The construction method of claim 6.

8. The step of constructing the structure includes a step of arranging a plurality of the precast members with scaffolding along a horizontal arrangement direction, The scaffolding-attached precast members have protruding portions in which horizontal reinforcing bars are embedded and which protrude from the end portions of the scaffolding-attached precast members in the juxtaposition direction and extend along the juxtaposition direction, In the step of arranging the precast members with scaffolding, the precast members with scaffolding are arranged so that the protruding portions face other precast members with scaffolding, After the step of arranging the scaffolding-attached precast members, a step of arranging a joint reinforcing bar in a space aligned with the protruding portion along a direction perpendicular to the horizontal direction, so as to extend in the juxtaposition direction together with the horizontal reinforcing bar; Pouring concrete into the space in which the joint reinforcing bars are arranged; Equipped with The method of claim 1.

9. The precast member with scaffolding has a plurality of protrusions arranged along the orthogonal direction and a space formed between the plurality of protrusions. The method of claim 8.

10. In the step of arranging the scaffold-attached precast members, the scaffold-attached precast members are arranged so that the protruding portions face each other along the arranging direction, and gaps are formed between the protruding portions.

10. The method of claim 8 or claim 9.

11. A step of fixing the joint reinforcing bar to the shear reinforcement bar protruding from the protruding portion in the orthogonal direction, The step of placing the joint reinforcing bar includes: The method includes a step of removing the joint reinforcing bar fixed in the fixing step from the shear reinforcement bar and sliding the joint reinforcing bar toward the other precast member with scaffolding.

10. The method of claim 8 or claim 9.

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