JP2020016140A - Method for manufacturing erection concrete structure in water area - Google Patents

Abstract

To provide a method for manufacturing an erection concrete structure in a water area which can efficiently manufacture a concrete structure installed on a pile standing in a water area.SOLUTION: A supporting 2 and a bottom formwork 14 extending between a plurality of spans of piles 20 erected in a water area WA, and the temporary scaffold 12 are integrally assembled in advance into a unit 1. The unit 1 is composed of a plurality of split bodies 1A and 1B that can be split. The unit 1 suspended above the plurality of spans is moved downward to be placed on a bracket 21 fixed to the pile 20. Then, a side formwork 15 is installed on the unit 1 and concrete 70 is placed in a formwork 13 constructed around the pile 20. After the concrete 70 has hardened, the unit 1 is split into each of the split bodies 1A and 1B and moved in the horizontal direction so as to be pulled out of an erected concrete structure 80 formed by hardening the concrete 70 and removed.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method for manufacturing an installed concrete structure in a water area, and more particularly, to a method for manufacturing an installed concrete structure in a water area capable of efficiently manufacturing a concrete structure installed on a pile standing in the water area. It is about.

  When manufacturing an erecting concrete structure such as a pier in a water area such as the sea or a river, first, a support member such as a bracket or a hanging material is installed on each of a plurality of piles erected in the water area. Then, by using the support member as a support, a shoring is constructed between adjacent piles near the water surface, and a formwork and a temporary scaffold are constructed on the shoring. Next, concrete is hardened by casting concrete in the formwork, and the formwork, the temporary scaffolding, and the shoring are removed to produce a erected concrete structure (for example, see Patent Document 1).

  As in the construction method described in Patent Literature 1, the support work and the work of assembling the temporary scaffolding are performed near the water surface. Therefore, work efficiency is lower than that of work on land or on a ship, and much work time is required. In addition, the work time is restricted by the influence of the tide level and the waves. Therefore, the work of supporting and assembling the temporary scaffolding in the construction water area has been a factor that hinders shortening of the construction period.

JP-A-2003-64632

  An object of the present invention is to provide a method of manufacturing an installed concrete structure in a water area where a concrete structure installed on a pile standing in the water area can be efficiently manufactured.

  In order to achieve the above object, a method of manufacturing an erecting concrete structure in a water area according to the present invention includes a method for supporting and forming a structure via a bracket fixed to the pile between spans of the piles erected in the water area. A construction step of constructing a frame, a concrete placing step of placing concrete in the formwork constructed around the pile, and removal of the support and the formwork after the concrete has hardened And performing the steps, in the method of manufacturing an erection concrete structure in a body of water for manufacturing an erection concrete structure erected between the spans, wherein the support and the mold extending across a plurality of the spans are provided. A unit in which the bottom formwork constituting the bottom surface of the frame and the temporary scaffold are integrated is pre-assembled, and this unit is composed of a plurality of divided bodies that can be separated. In the step, the unit suspended above the plurality of spans is moved downward and installed on the bracket located below the unit, and in the removing step, the units are each separated into the divided bodies. The concrete may be moved in a horizontal direction, pulled out of the erected concrete structure formed by hardening the concrete, and removed.

  According to the present invention, a unit in which the shoring and bottom formwork extending over a plurality of spans and the temporary scaffold are integrated is assembled in advance. Then, in the construction process, the unit is installed on a bracket fixed to the pile. This eliminates the need for the complicated work of assembling the support and assembling the temporary scaffold and installing the bottom formwork near the water surface of the construction water area. Further, supports, temporary scaffolds, and bottom forms can be collectively constructed over a plurality of spans. Along with this, it is possible to reduce the working time required for constructing the shoring, the temporary scaffolding, and the bottom formwork in the construction water area. Further, in the removal step, the support, the temporary scaffold, and the bottom formwork can be removed with a small number of man-hours by separating the unit into a plurality of divided bodies, pulling out the outside of the erected concrete structure and removing the unit. Therefore, an erecting concrete structure can be efficiently manufactured in a water area.

It is explanatory drawing which illustrates the situation which installed the suspended scaffolding on the pile in the bracket installation process of this invention by a side view. It is AA sectional drawing of FIG. It is explanatory drawing which illustrates the construction water area in the state which completed the bracket installation process of this invention in planar view. It is explanatory drawing which illustrates the situation which moves a unit downward from the upper position between spans in the construction process of this invention in sectional view. FIG. 5 is an explanatory view exemplifying a situation in which a unit is installed on the bracket of FIG. 4 in a plan view. It is explanatory drawing which illustrates the structure below the joist of the unit of FIG. 5 in plan view. FIG. 5 is an explanatory view exemplifying a situation in which a unit is installed on the bracket in FIG. 4 in a sectional view. It is explanatory drawing which illustrates the situation in which the concrete was cast in the formwork in the concrete casting process of this invention by sectional view. It is explanatory drawing which illustrates the situation which poured concrete in the formwork in another concrete view in the concrete placing process of this invention. It is explanatory drawing which illustrates the state which removes the divided body in the removal process of this invention by planar view. It is explanatory drawing which illustrates the manufactured erection concrete structure by sectional view.

  Hereinafter, a method for manufacturing an erecting concrete structure in a water body according to the present invention will be described based on the illustrated embodiment. The X direction in the figure indicates the extending direction (longitudinal direction) of the erection concrete structure 80 in the horizontal direction, the Y direction indicates the width direction of the erection concrete structure 80 orthogonal to the X direction in the horizontal direction, and the Z direction indicates The vertical direction is shown.

  In the present invention, the erection concrete structure 80 is manufactured by sequentially performing the bracket installation step, the construction step, the concrete placement step, and the removal step. Examples of the erection concrete structure 80 include a pier, a road bridge girder, and the like erected on a plurality of piles 20 erected in a water area WA such as an ocean, a river, or a lake. When the pile 20 is not erected in the water area WA where the construction is performed (hereinafter, referred to as the construction water area WA), the pile setting step is performed before the bracket installation step.

  As illustrated in FIG. 1, in the pile setting step, a plurality of piles 20 are set in the construction water area WA at intervals in the X direction. In this embodiment, a steel pipe pile is cast as the pile 20. However, the pile 20 may be formed of, for example, a steel pipe concrete pile or a concrete pile. The upper part of each pile 20 protrudes above the water surface WL. The pile 20 is cast by a known method.

  In the bracket installation step, the suspension scaffold 30 extending between a plurality of spans of the piles 20 erected in the construction water area WA is assembled in advance on land or on a ship. As illustrated in FIG. 1 and FIG. 2, in the construction water area WA, the lifting scaffold 30 is lifted to a position above a plurality of spans (in this embodiment, between two spans) using a hoist ship or a land-based crane. Then, the suspension scaffold 30 is moved downward, and is placed and erected on the upper surface of the plurality of piles 20 located below the suspension scaffold 30.

  The specific structure of the suspension scaffold 30 will be described with reference to the erected state. The suspension scaffold 30 has a main girder 31, a horizontal girder 32, a support 33, a support girder 34, a suspension girder 35, a scaffold plate 36, a handrail 37, and a ladder 38. The main girder 31, the horizontal girder 32, the support 33, the support girder 34, and the suspension girder 35 are made of, for example, a bucking steel material or an H-shaped steel. The scaffolding plate 36 is formed of, for example, a metal plate-like member or a net-like member.

  Two main girders 31 are mounted on the upper surfaces of the adjacent piles 20 spaced apart in the Y direction, and extend in the X direction across the three piles 20. On each of the main girders 31, six cross girders 32 extending in the Y direction at intervals in the X direction are joined in a state of being bridged. The lower ends of the cross beams 32 are joined to the upper ends of two columns 33 extending in the Z direction at intervals in the Y direction. The upper ends of the support beams 34 extending in the Y direction are joined to the lower ends of a pair of columns 33 adjacent in the Y direction. Each support girder 34 extends outside the outer peripheral surface of the pile 20 in the Y direction.

  A scaffold plate 36 is laid on the six support beams 34 so as to surround the outside of the three piles 20. A handrail 37 is provided on the scaffold plate 36, and a ladder 38 can be hung on the handrail 37. As illustrated in FIG. 1, a part of the scaffold plate 36 located near the pile 20 is configured by a detachable detachable panel 36 a. By removing the ladder 38 from the opening formed by removing the detachable panel 36a, the worker can use the ladder 38 to attach the bracket 21 to the pile 20 near the water surface WL below the scaffold plate 36. .

  At the lower end of the main girder 31, two suspension girder 35 extending in the Y direction with an interval in the X direction are joined. One hanging girder 35 is arranged between each span. Above both ends in the Y direction of each suspension girder 35, there is provided a suspending member 35 a for connecting the wire rope 60 of the crane when lifting the suspension scaffold 30. The structure and size of the suspension scaffold 30, the number of members constituting the suspension scaffold 30, the joining method of the members, and the like can be appropriately determined according to the construction conditions. For example, the suspension scaffold 30 extending over three spans or more can be used.

  When the erection of the suspension scaffolds 30 is completed, the brackets 21 are fixed to the respective stakes 20 by the mounting work of the worker on the suspension scaffolds 30. The bracket 21 is fixed to one side and the other side of the pile 20 in the Y direction. It is preferable that the bracket 21 be fixed to the pile 20 so that the vertical position can be changed.

  As illustrated in FIG. 1, in this embodiment, a metal hanging member 22 extending in the Z direction is joined to the outer peripheral surface of the pile 20 by welding, and the bracket 21 is formed of a bolt and a nut on the hanging member 22. It is detachably joined by a fixing bracket 23. The suspension member 22 has a plurality of round holes into which bolts are fitted. A plurality of round holes into which bolts are fitted and a long hole 21a extending in the Z direction are formed in the vertical member extending in the Z direction that forms the bracket 21. When the fixing of the bracket 21 with the bolt fitted in the round hole is released and the tightening of the bolt fitted in the long hole 21a is loosened, the fixing position of the bracket 21 with respect to the pile 20 using the long hole 21a is shifted in the Z direction. It has a structure that can be changed.

  The fixing position of the bracket 21 can be appropriately determined according to construction conditions and the like. In this embodiment, the bracket 21 is fixed near the water surface WL. The shape and size of the bracket 21, the method of fixing the bracket 21 to the pile 20, and the like are not limited to this embodiment, and may have different configurations. For example, the bracket 21 may be directly joined to the outer peripheral surface of the pile 20 by welding or the like.

  As illustrated in FIG. 3, after the mounting operation of the bracket 21 is completed, the suspension scaffold 30 is lifted by a crane or the like and removed from the construction water area WA. Thus, the bracket installation step is completed. As described above, the use of the suspension scaffold 30 allows the bracket 21 to be easily and efficiently attached. However, the diver or the worker on the boat mounts the bracket 21 without using the suspension scaffold 30. Is also good. When the bracket 21 is already fixed to the stake 20, the bracket installation step can be omitted.

  Next, in the construction process, between the plurality of spans of the piles 20 erected in the construction water area WA, the support 2, the temporary scaffold 12, and the formwork 13 are connected via the bracket 21 fixed to the pile 20. To construct. The support 2 is a framework that supports the formwork 13 with respect to the pile 20. The temporary scaffold 12 is a scaffold for a worker who performs an assembling work and a reinforcing work of the formwork 13, and has a scaffold plate 12a and a handrail 12b. The mold 13 is a frame on which concrete is cast, and has a bottom mold 14 constituting a bottom surface and a side mold 15 constituting a side surface.

  As illustrated in FIG. 4, in the present invention, the unit 1 in which the support 2 and the bottom formwork 14 extending over a plurality of spans and the temporary scaffold 12 are integrated is pre-installed on land or on a ship. Assemble it. The unit 1 is composed of a plurality of separated bodies 1A and 1B that can be separated. The assembly of the unit 1 is preferably completed before the bracket installation step is completed, but may be performed after the bracket installation step.

  In the construction process, the previously assembled unit 1 is lifted to an upper position between a plurality of spans using a crane and an installation jig 40. Then, the unit 1 is moved downward and installed on the bracket 21 located below the unit 1. The installation jig 40 is a suspending jig interposed between the wire rope 60 of the crane and the unit 1 when suspending the unit 1 in the construction process.

  The specific structure of the unit 1 will be described with reference to a state where the unit 1 is installed on the bracket 21. As illustrated in FIGS. 5 to 7, the unit 1 of this embodiment extends in the X direction over two spans. An opening 1a through which the stake 20 can be inserted is provided at a central portion of the unit 1 in a plan view, and a groove forming a part of the opening 1a is provided at a central portion in the Y direction at both ends in the X direction of the unit 1. 1b is provided. By installing the plurality of units 1 adjacent to each other in the X direction, it is possible to construct the support 2, the bottom form 14, and the temporary scaffold 12 that are continuous over three or more spans. An opening 1a is formed when the grooves 1b of two adjacent units 1 are joined together.

  As illustrated in FIG. 5, the unit 1 has a structure that can be separated into the divided body 1A on one side and the divided body 1B on the other side of the separation line SL extending in the X direction and having the position of the pile 20 as a boundary. I have. In the drawing, the separation line SL is indicated by a dashed line. Each of the two divided bodies 1A, 1B has a shoring 2, a bottom formwork 14, and a temporary scaffold 12, and detaches the opposing ends of the shoring 2 constituting each of the divided bodies 1A, 1B. It is configured so that it can be connected as much as possible.

  As illustrated in FIGS. 6 and 7, the support 2 includes a main girder 3, a horizontal girder 4, a joist 5, a hanging girder 6, and a support member 7. The main girder 3 extends in the X direction over a plurality of spans, and is mounted on the bracket 21. The main girder 3 is made of, for example, a mountain retaining steel material or an H-shaped steel. A plurality of main girders 3 are arranged on the one side and the other side of the pile 20 in the Y direction at intervals from each other in the Y direction. When the unit 1 is installed on the bracket 21, the main girder 3 is placed on a horizontal member extending in the Y direction that constitutes the bracket 21, and the horizontal member and the main girder 3 are fixed by Bullman. The unit 1 is fixed to the bracket 21 by fixing with the metal fittings 11. The mounting operation of the fixing fitting 11 is performed by, for example, a diver.

  The cross beam 4 is fixed on the main beam 3 and extends in the Y direction. The cross beam 4 is made of, for example, a metal frame material or a square steel pipe. A plurality of cross beams 4 are arranged between the piles 20 and on one side and the other side of the pile 20 in the Y direction with a space therebetween in the X direction. Each cross beam 4 arranged between the piles 20 is composed of two cross beams 4 which are detachably connected to each other at a position of the separation line SL by a fixing bracket 4a composed of a bolt and a nut. ing. In this unit 1, when the connection by the fixing bracket 4a is released, the unit 1 is separated into the divided body 1A on one side and the divided body 1B on the other side. Each of the cross beams 4 and the main beam 3 are joined by a fixing bracket 8 composed of a bolt and a nut.

  The joist 5 is fixed on the cross beam 4 and extends in the X direction. The joist 5 is made of, for example, a wooden square or a metal frame. A plurality of joists 5 are arranged at intervals in the Y direction at positions avoiding the opening 1a and the groove 1b in the center of the unit 1 in the Y direction. Each of the joists 5 and the cross beams 4 are joined with an annealed iron wire or the like.

  The suspension girder 6 is fixed below the main girder 3 and extends in the Y direction. The suspension girder 6 is made of, for example, a stake steel material or an H-shaped steel. Suspended girders 6 are provided on one side and the other side in the Y direction via separation lines SL between the respective spans. At the outer end of each of the hanging girders 6, a hanging metal fitting 6a to which a wire rope can be connected is provided. Each of the hanging girders 6 and the main girders 3 are joined by a fixture 9 made of Bullman.

  The support member 7 is a member that supports a rear fitting panel 14a described later. The support member 7 is made of, for example, an H-shaped steel or metal frame member, a wooden square member, or the like. The support member 7 of this embodiment is composed of an H-shaped steel and a square member fixed on the H-shaped steel. The support member 7 is fixed on the main girder 3 and extends in the Y direction. A plurality of supporting members 7 are arranged at intervals on the one side and the other side in the Y direction via the separation line SL near the pile 20 in the X direction. Each support member 7 and the main girder 3 are fixed by a fixing fitting 10 made of Bullman.

  The bottom formwork 14 of this embodiment is formed of a steel plate member. The bottom formwork 14 can also be constituted by, for example, a wooden plate-like member. As illustrated in FIG. 5, the bottom form 14 is fixed on the joist 5, and the bottom form 14 has an opening larger than the outer size of the pile 20 at a position corresponding to the opening 1 a and the groove 1 b. And a groove are formed. A part of the cross beam 4 and a part of the support member 7 are located below the opening and the groove of the bottom formwork 14, respectively. The bottom formwork 14 is configured to be divided into one side and the other side in the Y direction at the position of the separation line SL.

  Scaffolding plates 12a are laid on one side outer side and the other side outer side in the Y direction of the bottom formwork 14, respectively. The scaffold plate 12a is formed of, for example, a metal net-like member or a plate-like member. The scaffold plate 12a is fixed on the cross beam 4 and extends in the X direction. The scaffold plate 12a and the cross beam 4 are joined by welding. A handrail 12b extending in the X direction along the scaffold 12a is provided outside the scaffold 12a in the Y direction. The lower part of the support of the handrail 12 b is fixed to the outer end of the cross beam 4. The structure and size of the unit 1, the number of members constituting the unit 1, the joining method of the members, and the like can be appropriately determined according to the construction conditions.

  As illustrated in FIG. 4, the installation jig 40 includes a frame body 41 in which two main members extending in the X direction and two horizontal members extending in the Y direction are combined in a lattice shape, It has the frame 41 and four wire ropes 44 connecting the unit 1. The main member and the cross member are made of, for example, a stake steel material or an H-shaped steel. At the upper part of the frame body 41, four hanging members 42 are provided at intervals in the X direction and the Y direction. At the lower part of the frame body 41, the suspending members 43 are provided at positions overlapping the respective suspending members 6a provided in the unit 1 in plan view.

  When the installation work of the unit 1 is performed, the wire ropes 60 of the crane are connected to the hanging members 42 on the upper side of the frame 41, respectively, and the hanging member 43 on the lower side of the frame 41 and the hanging member 6a of the unit 1 are connected. Each is connected by a wire rope 44. When the unit 1 is suspended, the respective wire ropes 44 extend in a substantially vertical direction.

  As described above, if the unit 1 is hung in a state where the wire ropes 44 extend in the substantially vertical direction using the installation jig 40, the inclination of the unit 1 can be suppressed, so that the unit 1 can be moved in a stable state. Can be. Use of the installation jig 40 is optional.

  When the unit 1 is moved downward and installed on the bracket 21 located below the unit 1, the respective piles 20 penetrate the unit 1 up and down, and the units 1 are fixed to the upper ends of the respective piles 20. Is done.

  As illustrated in FIG. 5, after the unit 1 is installed on the bracket 21, the rear fitting panel 14 a for closing the gap is provided between the edge of the opening of the bottom formwork 14 and the outer peripheral surface of the pile 20. Insert and fix. The rear fitting panel 14a is in a state of being supported by the support members 7 and the cross beams 3. The rear fitting panel 14a is configured to be divided into one side and the other side in the Y direction at the position of the separation line SL.

  Next, the reinforcing bars constituting the erected concrete structure 80 are installed on the bottom formwork 14 by the operator's reinforcing work on the unit 1. In the figure, the reinforcing bars are omitted. As illustrated in FIG. 8 and FIG. 9, after completing the reinforcing work, the side formwork 15 is installed outside the pile 20 and the reinforcing bar on the bottom formwork 14 and the mold surrounding the pile 20 and the reinforcing bar. The frame 13 is completed. Thus, the construction process is completed. The arrangement and fixing method of the side formwork 15 can be appropriately determined according to the construction conditions.

  After the completion of the construction step, a concrete placing step of placing the cast-in-place concrete 70 into the formwork 13 is performed. After the curing of the concrete 70 after the curing period, a removal step of removing the support 2, the temporary scaffold 12, and the formwork 13 from the construction water area WA is performed.

  In the removal process, the worker on the temporary scaffold 12 removes the side formwork 15 from the erected concrete structure 80 formed by hardening the concrete 70. Then, the side mold 15 is removed from above the unit 1 using a crane or the like. Next, the divided bodies 1A and 1B are suspended at the current fixed position using the crane and the removal jig 50, and the load of the divided bodies 1A and 1B is supported by the crane.

  As illustrated in FIG. 10, the removal jig 50 is a suspension jig interposed between the wire rope 60 of the crane and the divided body 1A (1B) when removing the divided body 1A (1B). . The removal jig 50 includes one rod 51 extending in the X direction, and two wire ropes 54 connecting the rod 51 and the divided body 1A (1B). The rod-shaped body 51 is made of, for example, a mountain retaining steel material or an H-shaped steel. The rod-shaped body 51 is provided with hanging members 52 for connecting the wire ropes 60 of the crane at two places with an interval in the X direction. The rod-shaped body 51 is further provided with hanging fittings 53 for connecting one end of the wire rope 54 at two places with an interval in the X direction. The distance in the X direction between the hanging members 53 is set to the same distance as the distance in the X direction between the hanging members 6a of the divided body 1A (1B).

  The work of connecting the wire rope 54 of the removal jig 50 to the hanging metal fitting 6a of the divided body 1A (1B) is performed by a worker working on the temporary scaffold 12. When the worker who has been working on the temporary scaffold 12 completes the connection work of the wire rope 54, the worker retreats from the unit 1 to be removed.

  Then, the unit 1 is separated into the divided body 1A on one side and the divided body 1B on the other side of the separation line SL by releasing the connection between the cross beams 4 by the fixing bracket 4a by a diver or the like. Next, a bolt fitted into the round hole of the fixing fitting 11 for fixing the bracket 21 to the pile 20 is removed from the bracket 21 by a diver or the like. Next, tightening by the bolt inserted into the long hole 21a of the bracket 21 is loosened. Then, the fixing position of the bracket 21 is moved downward using the long hole 21a. At this time, the unit 1 is moved downward together with the bracket 21 while supporting the loads of the divided bodies 1A and 1B by the crane and the removal jig 50. Thereby, a gap is formed between the lower surface of the erected concrete structure 80 and the bottom formwork 14. The operation of separating the unit 1 into the plurality of divided bodies 1A and 1B and the operation of moving the bracket 21 and the unit 1 downward may be performed in a different order.

  Next, each of the divided bodies 1A and 1B is pulled and moved in a horizontal direction using a crane and a removal jig 50, and each of the divided bodies 1A and 1B is pulled out of the erected concrete structure 80 and removed. The divided body 1A on one side is pulled out to the outside on one side in the Y direction and removed, and the divided body 1B on the other side is pulled out to the outside on the other side and removed. Thus, the removal process is completed.

  As described above, by using the removal jig 50, the divided body 1A (1B) can be stably pulled out in the horizontal direction. The use of the removal jig 50 is optional. The operation of towing the divided bodies 1A and 1B in the horizontal direction may be performed by using a winch or the like installed on a large ship or on land together with a crane.

  As illustrated in FIG. 11, when the removal step is completed, the manufacture of the erected concrete structure 80 is completed. The bracket 21 and the hanging member 22 fixed to the pile 20 may be removed or may be left as they are. By similarly manufacturing the erected concrete structure 80 between the other plurality of spans, a structure in which the erected concrete structures 80 are continuous can be obtained.

  In the present invention, as described above, the unit 1 assembled in advance is installed on the bracket 21 fixed to the pile 20. This eliminates the need for the complicated work of assembling the support 2 and the temporary scaffolding 12 and installing the bottom formwork 14 near the water surface WL of the construction water area WA. Further, the support 2, the temporary scaffold 12, and the bottom formwork 14 can be collectively constructed over a plurality of spans. Along with this, it is possible to reduce the work time required for constructing the shoring 2, the temporary scaffold 12, and the bottom formwork 14 in the construction water area WA.

  Furthermore, in the removal step, the unit 1 is separated into a plurality of divided bodies 1A and 1B, pulled out to the outside of the erected concrete structure 80, and removed to reduce the number of the support 2, the temporary scaffold 12, and the bottom formwork 14. It can be removed in man-hours. Therefore, the erection concrete structure 80 can be efficiently manufactured even in the construction water area WA where there is a concern that the work time is restricted by the influence of the tide level and the influence of the waves. Accordingly, the construction period can be shortened.

  The unit 1 can be reused without being limited to one-time construction. The unit 1 can be easily and quickly restored in a short time by connecting and integrating the divided bodies 1A and 1B recovered in the removal step on land or on a ship. Therefore, it is very useful to reduce the number of work steps and manufacturing cost required for manufacturing the erected concrete structure 80.

  When the bottom formwork 14 is made of a steel plate-like member, it is possible to more reliably prevent the bottom formwork 14 from being damaged by lift pressure such as wake waves. become. Further, since the durability of the bottom formwork 14 is higher than the case where the bottom formwork 14 is made of a wooden plate-like member, even when the unit 1 is used a plurality of times, the bottom formwork 14 is newly formed. The frequency of replacing with a different member can be reduced. On the other hand, when the bottom formwork 14 is made of a wooden plate-like member, there is an advantage that the weight of the unit 1 can be reduced.

  In the removal process, if the unit 1 is separated into two divided bodies 1A and 1B on one side and the other side of the separation line SL with the position of the pile 20 as a boundary, the number of work steps required for the removal process can be reduced. It will be advantageous. Even when the unit 1 is reused, the number of work steps required for connecting the divided bodies 1A and 1B can be reduced.

  The position of the separation line SL that divides the unit 1 and the number of divided bodies that make up the unit 1 may be configured differently from the above-described embodiment. For example, the unit 1 can be composed of three or more divided bodies. When the unit 1 is composed of three or more divided bodies, there is an advantage that each divided body can be reduced in size and weight.

  In the removing process, the divided bodies 1A and 1B may be horizontally moved without moving the fixed position of the bracket 21, but as in this embodiment, before the divided bodies 1A and 1B are horizontally moved, It is preferable to move the fixed position of 21 downward. By lowering the fixing position of the bracket 21, a gap can be formed between the lower surface of the erected concrete structure 80 and the bottom formwork 14, and the divided bodies 1A and 1B can be more easily pulled out of the erected concrete structure 80. Become.

  In the above-described embodiment, the unit 1 extending over two spans has been described as an example, but the unit 1 may extend over three or more spans. Further, the manufacturing method of the present invention sets a plurality of piles 20 by setting the position of the separation line SL, the number of divided bodies, the number and arrangement of the openings 1a and the grooves 1b of the unit 1 according to the arrangement of the piles. Is not limited to being arranged on a straight line, but can be adopted also when the plurality of piles 20 are arranged in another manner.

DESCRIPTION OF SYMBOLS 1 Unit 1a Opening 1b Groove 1A, 1B Dividing body 2 Support 3 Main girder 4 Cross girder 4a Fixing metal 5 Joist material 6 Hanging girder 6a Hanging metal 7 Supporting materials 8-11 Fixing metal 12 Temporary scaffold 12a Scaffolding plate 12b Handrail 13 Formwork 14 Bottom formwork 14a Back fitting panel 15 Side formwork 20 Pile 21 Bracket 21a Long hole 22 Suspension member 23 Fixture 30 Suspension scaffold 31 Main girder 32 Horizontal girder 33 Support column 34 Support girder 35 Suspension girder 35a Suspension fitting 36 Scaffolding board 36a Detachable panel 37 Handrail 38 Ladder 40 Installation jig 41 Frames 42, 43 Hanging fittings 44 Wire rope 50 Removal jig 51 Rod-shaped bodies 52, 53 Hanging fittings 54 Wire rope 60 (of crane) Wire rope 70 Concrete 80 Construction concrete structure SL Separation line WA Water area WL Water surface

Claims (5)

A construction step of constructing a shoring and formwork via a bracket fixed to the pile between the spans of the piles erected in the water area, and concrete in the formwork constructed around the pile A water area for producing an installed concrete structure to be installed between the spans by performing a concrete installation step of installing concrete and a removal step of removing the support and the formwork after the concrete has hardened. In the method of manufacturing an erected concrete structure in
A unit in which the supporting form extending over the plurality of spans and the bottom formwork forming the bottom surface of the formwork and a temporary scaffold are assembled in advance, and a plurality of divisions capable of separating the unit are provided. In the construction step, the unit suspended above the plurality of spans is moved downward and installed on the bracket located below the unit. A method for manufacturing an installed concrete structure in a water area, comprising separating the object into separate pieces and moving the split body in a horizontal direction, and pulling out and removing the installed concrete structure formed by hardening the concrete.   The method according to claim 1, wherein the bottom form is a steel plate member.   In the removing step, the unit is separated into two divided bodies on one side and the other side of a separation line extending in the extending direction and bordering the position of the pile, and the divided body on the one side is 3. The method according to claim 1, wherein the structure is drawn out to one side and removed, and the divided body on the other side is drawn out to the outside on the other side and removed. 4.   The bracket is fixed to the pile so that the vertical position can be changed, and in the removing step, the fixing position of the bracket is moved downward, thereby moving the unit downward, and 4. The method according to claim 1, wherein after forming a gap between the lower surface of the structure and the bottom formwork, each of the divided bodies is moved in a horizontal direction. 5. Method.   In the bracket installation step performed before the construction step, a suspension scaffold extending across the plurality of spans is previously assembled, and the suspension scaffold lifted to an upper position between the plurality of spans is moved downward. It is placed and erected on the upper surface of the plurality of piles located thereunder, and then, after fixing the bracket to the outer peripheral surface of the pile by an operator's mounting work on the suspension scaffold, the suspension scaffold is lifted. The method for manufacturing an installed concrete structure in a water body according to any one of claims 1 to 4, wherein the concrete structure is removed.

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