Formwork structure

Abstract

To provide formwork structure capable of supporting vertical load and horizontal load acting on formwork when concrete is placed, with simple constitution.SOLUTION: Form structure 40 is for constructing a slope portion of an arch member of an arch bridge by using concrete 32. The form structure 40 includes: a falsework that supports a bottom falsework 50 upon concrete placement; PC steel material 44 which is arranged in such an inclined manner that it is orthogonal to the slope of the slope portion and which has an upper end portion fixed to a meran material 31 and a lower end portion fixed to the falsework; and beam material 46 which is arranged between the meran material 31 and the falsework and bears compressive force accompanied with tension of the PC steel material 44.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a formwork structure used when constructing an inclined portion of an arch member of an arch bridge. [Background technology]

[0002] An arch bridge is a bridge that supports vertical loads using arch members. One method of constructing arch members is the Melange method, in which concrete is poured to embed an arch-shaped Melange material (see, for example, Patent Documents 1-3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 60-15763 [Patent Document 2] JP 2004-11196 A [Patent Document 3] Japanese Patent Application Publication No. 8-68014 Summary of the Invention [Problem to be solved by the invention]

[0004] The formwork used when pouring concrete is often supported by hanging members that hang vertically downward from a mobile work vehicle (VW) installed on the existing part of the arch member. However, in the inclined part of the arch member, pouring concrete generates not only vertical load but also horizontal load on the formwork. Therefore, the formwork, its hanging members, mobile work vehicle, etc. must be structured to withstand horizontal loads, which increases costs.

[0005] The present invention has been made in consideration of the above problems, and aims to provide a formwork structure etc. that has a simple configuration and can support vertical and horizontal loads when pouring concrete. [Means for solving the problem]

[0006] The present invention, which aims to solve the above-mentioned problems, is a formwork structure for constructing the inclined portion of the arch member of an arch bridge with concrete, characterized in that it has a support that supports the bottom formwork when pouring concrete, a tension member that is arranged at a slope perpendicular to the slope of the inclined portion, with its upper end fixed to a melan material and its lower end fixed to the support, and a bundle member that is arranged between the melan material and the support and that bears the compressive force associated with the tension of the tension member.

[0007] In the present invention, a tension member such as a PC steel bar having a slope perpendicular to the slope of the inclined portion of the arch member is used, and the compressive force generated by tensioning the tension member can resist the load of the concrete poured on the bottom formwork. This makes it possible to support the vertical and horizontal loads generated when pouring concrete with a simple structure. Furthermore, a bundle is provided between the shoring and the melange material that fixes both ends of the tension member, and the bundle functions as a brace to prevent the gap between the bottom formwork and the melange material from narrowing due to the compressive force applied by the tension member, and the gap between the bottom formwork and the melange material can be kept constant.

[0008] It is desirable that the support structure has a girder arranged below the bottom formwork and an anchoring member arranged below the girder, and that the lower end of the tension member is fixed to the anchoring member. This allows the bottom formwork to be supported appropriately via the shoring.

[0009] It is preferable that the Mellan material has a cylindrical main girder along the bridge axis direction, the inside of the main girder is filled with filler concrete, the tendons are passed through a cylinder arranged inside the main girder, and the upper end of the tendons is fixed to the upper surface of the main girder. It is also preferable that a cylinder surrounding the bundle is provided between the Mellan material and the bottom formwork. The Melang material can be a highly rigid structure in which the cylindrical main girder is filled with infill concrete, and in this case, the tendons can be passed through the main girder and their upper ends can be fixed to the top surface of the main girder. Also, by providing a cylinder through which the tendons pass within the main girder, the infill concrete can be prevented from adhering to the tendons. On the other hand, by providing a cylinder that surrounds the bundle between the Melang material and the bottom formwork, the concrete of the arch member can be prevented from adhering to the bundle. Effect of the Invention

[0010] The present invention makes it possible to provide a formwork structure etc. that has a simple configuration and is capable of supporting vertical and horizontal loads during concrete pouring. [Brief description of the drawings]

[0011] [Figure 1] A diagram showing arch bridge 1. [Diagram 2] 4A to 4C are diagrams showing the construction procedure of the arch member 3. [Diagram 3] FIG. 4 is a diagram showing an example of a unit 400. [Figure 4] FIG. [Diagram 5] A diagram showing a formwork structure 40. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[0013] (1. Arch Bridge 1) Fig. 1 is a simplified diagram showing an arch bridge 1 constructed using a formwork structure according to an embodiment of the present invention. The arch bridge 1 of this embodiment is a bridge with multiple spans, and Fig. 1 shows the central span of the bridge.

[0014] In the arch bridge 1, arch members 3 are provided between piers 2, and superstructure 5 such as stiffening girders is supported by vertical members 4 rising from the arch members 3. In this embodiment, the arch members 3 are made of reinforced concrete (RC). In addition to reinforcing bars, melamine materials (described later) are also embedded in the concrete of the arch members 3.

[0015] In the side span portion of the arch bridge 1, the arch member 3 is provided between the pier 2 and the abutment (not shown), and in the single-span arch bridge 1, the arch member 3 is provided between the abutments, but the other configuration is approximately the same as above.

[0016] (2. Construction method and formwork structure of arch bridge 1 40) When constructing the arch bridge 1, an arch member 3 is constructed between the piers 2. Figure 2 is a diagram showing an outline of the procedure for constructing the arch member 3 between the piers 2.

[0017] As shown in Fig. 2(a), in this embodiment, when constructing the arch member 3, a temporary scaffolding 10 is constructed between the piers 2. The scaffolding 10 is also provided with a support 300 for installing the unit 400. Some of the supports 300 are also provided with a temporary support portion 301 for temporarily supporting the Mellan material 31.

[0018] 3 is an example of the unit 400, and shows a side view of the unit 400. The unit 400 is formed by assembling a support beam 41, a cross beam 42, and a temporary frame 43 on the ground.

[0019] The support girder 41 is a member arranged below the bottom formwork described below, and the cross girder 42 is a member that supports the support girder 41 from below. The temporary mounting stand 43 is a mounting stand for arranging the support girder 41 in a direction that matches the inclination of the arch member 3 in the vertical plane (hereinafter simply referred to as "inclination"), and is made of steel material or the like.

[0020] The support girders 41 are girder materials in the bridge axis direction of the arch bridge 1, and multiple ones are arranged in parallel with gaps in the direction orthogonal to the bridge axis of the arch bridge 1. The bridge axis direction of the arch bridge 1 corresponds to the left-right direction in Figure 3, and the direction orthogonal to the bridge axis corresponds to the normal direction to the page in Figure 3. The cross girders 42 are girder materials in the direction orthogonal to the bridge axis of the arch bridge 1, and multiple ones are arranged in parallel with gaps in the bridge axis direction of the arch bridge 1. Steel materials such as H-shaped steel are used for the support girders 41 and cross girders 42.

[0021] In this manner, in this embodiment, by assembling the support girder 41, cross girder 42, and temporary mounting base 43 on the ground and forming them into a unit, dangerous work such as tightening bolts at high altitudes can be reduced, and it also becomes easier to remove the unit 400 after the arch member 3 is constructed.

[0022] The melan material 31 is a curved steel member, and its curved shape corresponds to the shape of the arch member 3. The melan material 31 is temporarily supported on the scaffolding 10 by the temporary support parts 301 and the like.

[0023] Fig. 4 is a diagram showing the Mellan material 31. The Mellan material 31 has a configuration in which a plurality of (five in the example of Fig. 4) main girders 311 arranged in parallel are connected by steel connecting members 312.

[0024] The main girder 311 is a member that extends in the bridge axis direction of the arch bridge 1, and multiple members are arranged at intervals in the direction perpendicular to the bridge axis. In the vertical plane, the main girder 311 has a curved shape that matches the curve of the arch member 3. The main girder 311 is a tubular steel member with a rectangular cross section, and its interior will be filled with filler concrete in a later process.

[0025] In this embodiment, a plurality of Melang materials 31 are arranged continuously in the bridge axis direction of the arch bridge 1 between the piers 2. The main girders 311 of the Melang materials 31 adjacent to each other in the bridge axis direction are fixed to each other with bolts or the like, and the end of the main girder 311 on the pier 2 side of the Melang material 31 is fixed to the pier 2. By erecting the Melang materials 31 in this manner, the temporary support 301 can be removed, after which a cylinder, which will be described later, is placed inside the main girder 311 and filled with filler concrete.

[0026] Next, as shown in Fig. 2(b), a formwork structure is formed including a bottom formwork 50 for pouring concrete for the arch member 3. Fig. 5 is a diagram showing a formwork structure 40 for the inclined portion of the arch member 3. Fig. 5(a) is a diagram showing a vertical cross section of the formwork structure 40 along the bridge axis direction, and Fig. 5(b) is a diagram showing a cross section perpendicular to the axis of the main girder 311. Fig. 5(a) is a cross section along line BB in Fig. 5(b), and Fig. 5(b) is a cross section along line AA in Fig. 5(a).

[0027] In this embodiment, a bottom formwork 50 is placed on the support beam 41 of the unit 400 (see FIG. 3), and the support beam 41 and cross beam 42 are supported from the Mellan material 31 by the PC steel 44. The compressive force generated by tensioning the PC steel 44 resists the load of the concrete 32 to be poured on the bottom formwork 50 in a later process.

[0028] 5(a) and (b), the position of the upper surface of the concrete 32 is indicated by a dashed line. Also, in Fig. 5(a) and (b), the temporary stand 43 of the unit 400 is omitted. In this embodiment, since it is difficult to install the support girders 41 and cross girders 42 after the bottom formwork 50 is installed, the support girders 41 and cross girders 42 are installed in advance by installing the unit 400 described above.

[0029] The PC steel members 44 are tendons arranged at an angle perpendicular to the angle of the inclined portion of the arch member 3, and PC steel bars are used, for example. A plurality of PC steel members 44 are arranged at intervals in the bridge axis direction, and the upper end of each PC steel member 44 is fixed to the upper surface of the main girder 311 of the Mellan member 31. The lower end of each PC steel member 44 is fixed to the lower surface of the fixing member 45.

[0030] The anchoring member 45 is a girder-shaped member extending in the bridge axis direction, and is disposed below the support girder 41 and the cross girder 42. For example, as shown in Fig. 5(b), the anchoring member 45 is a pair of steel beams having a U-shaped cross section, arranged with their vertical parts back to back, and the lower end of the PC steel member 44 is passed between the vertical parts of these steel beams, and the anchoring member 45 is fixed on an anchoring plate 441 that is bridged between the lower surfaces of both steel beams. The anchoring member 45 is provided across multiple cross girder 42, and its upper surface abuts against the lower surface of each cross girder 42. The anchoring member 45, the support girder 41, and the cross girder 42 constitute a support structure that supports the bottom formwork 50 in the present invention.

[0031] The upper part of the PC steel 44 penetrates the main girder 311 of the Mellan material 31, and the upper end of the PC steel 44 is tensioned and fixed on an anchoring plate 441 provided on the upper surface of the main girder 311. Inside the main girder 311, the PC steel 44 is arranged passing through a cylindrical body 47 such as a sheath.

[0032] Within the main girder 311, reinforcing materials such as cross beams may be arranged in plate form along a plane perpendicular to the axial direction of the main girder 311 (the plane shown in Figure 5 (b)). If the PC steel 44 were installed in the vertical direction, interference with the cross beams, etc. would be likely to occur. However, in this embodiment, the PC steel 44 is oriented in a direction perpendicular to the inclination of the inclined portion of the arch member 3, i.e., in a direction perpendicular to the axial direction of the main girder 311, so that the PC steel 44 can be easily arranged while avoiding the cross beams, etc.

[0033] Between the fixing member 45 and the mellan material 31, a bundle 46 is arranged so as to penetrate the bottom formwork 50. For example, a square tubular steel pipe is used for the bundle 46, and the lower part of the PC steel 44 is passed through the bundle 46. The bundle 46 bears the compressive force generated by the tension of the PC steel 44. In this embodiment, the compressive force from the PC steel 44 provides resistance to the concrete load, while the bundle 46, which functions as a brace, prevents the gap between the mellan material 31 and the bottom formwork 50 from narrowing due to the compressive force. In addition, a cylindrical body 48 such as a sheath is provided between the mellan material 31 and the bottom formwork 50 so as to surround the bundle 46.

[0034] As for the formwork structure 40, formwork (side formwork, etc.) other than the bottom formwork 50 of the arch member 3 is also arranged, and the reinforcing bars (not shown) of the arch member 3 are also arranged within these formworks. The above is an explanation of the formwork structure 40 for the inclined portion of the arch member 3, but for the horizontal portion in the center of the span of the arch member 3, the shoring supporting the bottom formwork 50 can be configured to be suspended from the melamine material 31 by vertical suspension members or the like.

[0035] After forming the formwork structure 40 as described above, concrete 32 is poured on the bottom formwork 50 so as to bury the melamine material 31, as shown in Fig. 2(c). The concrete 32 is poured successively from both piers 2 toward the center of the span, and in the inclined parts of the arch member 3, the vertical and horizontal loads during concrete pouring are supported by PC steel members 44 (see Fig. 5(a) etc.) with a slope perpendicular to the sloped parts. Finally, the arch member 3 of the arch bridge 1 is constructed by pouring the concrete 32 in the center of the span (closure part).

[0036] The formwork structure 40 is removed after the concrete 32 has hardened. As shown in FIG. 5(b), the PC steel bars 44 are passed through the tubes 47 and the beams 46, and are prevented from adhering to the filled concrete 33 in the main girder 311 and the concrete 32 of the arch member 3, making their removal easy. The beams 46 are also prevented from adhering to the concrete 32 of the arch member 3 by the tubes 48, making their removal easy. The voids left after the PC steel bars 44 and the beams 46 are removed are filled with a filler material (not shown) such as mortar. The scaffolding 10 and the like are also removed when they are no longer needed.

[0037] The above is an explanation of the procedure for constructing the arch member 3 between the piers 2, but the same procedure can be used when constructing the arch member 3 between the piers 2 and abutments, or when constructing the arch member 3 between the abutments of a single-span arch bridge 1. Furthermore, in addition to the arch members 3, the vertical members 4 and superstructure 5 are also constructed for the arch bridge 1. The vertical members 4 and superstructure 5 can be constructed using normal methods, so their explanation will be omitted here.

[0038] As described above, in this embodiment, the PC steel 44 having a slope perpendicular to the slope of the sloped portion of the arch member 3 is used, and the compressive force generated by tensioning the PC steel 44 can resist the load of the concrete 32 poured on the bottom formwork 50. This makes it possible to support the vertical load and horizontal load generated when pouring concrete with a simple configuration. Furthermore, a bundle 46 is provided between the melanin material 31 that fixes both ends of the PC steel 44 and the fixing member 45, and the bundle 46 functions as a brace, preventing the gap between the bottom formwork 50 and the melanin material 31 from narrowing due to the compressive force applied from the PC steel 44, and the gap between the bottom formwork 50 and the melanin material 31 can be kept constant to ensure sufficient cover.

[0039] In addition, in this embodiment, girder materials such as support girders 41 and cross girders 42 and fixing members 45 are used as supports for the bottom formwork 50, and the lower ends of the PC steel members 44 are fixed to the fixing members 45, so that the bottom formwork 50 can be suitably supported via these supports.

[0040] In this embodiment, the Mellan material 31 has a high-rigidity structure in which the filler concrete 33 is filled in the cylindrical main girder 311, and the PC steel 44 can be passed through the main girder 311 and its upper end can be fixed to the upper surface of the main girder 311. Also, by providing a cylinder 47 through which the PC steel 44 passes in the main girder 311, the filler concrete 33 can be prevented from adhering to the PC steel 44, and the PC steel 44 can be easily removed. Meanwhile, by providing a cylinder 48 surrounding the bundle 46 between the Mellan material 31 and the bottom formwork 50, the concrete 32 of the arch member 3 can be prevented from adhering to the bundle 46, and the bundle 46 can be easily removed.

[0041] However, the present invention is not limited to the above embodiment. For example, the shape and configuration of the arch bridge 1 are not limited to those described in Fig. 1, etc., as long as the arch member 3 is bridged between the piers 2, etc. Various configurations of the superstructure 5, etc. are possible. Furthermore, the specific configuration of the curved Melange material 31 is not limited to the above.

[0042] Furthermore, the configuration of the formwork structure 40 is not limited to the above, and may be any configuration that supports the bottom formwork 50 from below with shoring and resists the load of concrete poured onto the bottom formwork 50 with the PC steel members 44 arranged at an angle. For example, the bundle members 46 are not limited to the square tube-shaped ones as described above, and solid bundle members can be installed away from the positions of the PC steel members 44.

[0043] Although the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, the present invention is not limited to the above examples. It is clear that a person skilled in the art can come up with various modified or altered examples within the scope of the technical ideas disclosed in this application, and it is understood that these also naturally belong to the technical scope of the present invention. [Explanation of symbols]

[0044] 1: Arch bridge 2: Bridge pier 3: Arch member 31: Melange wood 32: Concrete 33: Filling concrete 40: Formwork structure 41: Receiving column 42: Crossbeam 43: Temporary stand 44:PC steel material 45: Fixing material 46: Bundle material 47, 48: Cylindrical body 50: Bottom formwork 311: Main girder 312:Connector

Claims

1. A formwork structure for constructing the inclined portion of an arch member of an arch bridge with concrete, A support structure that supports the bottom formwork when pouring concrete; A tendon is arranged at an angle perpendicular to the inclination of the inclined portion, and an upper end is fixed to the Mellan material and a lower end is fixed to the support; A bundle arranged between the Mellan material and the support for bearing a compressive force caused by tensioning the tension member; A formwork structure comprising:

2. The shoring is: A girder material disposed below the bottom formwork; An anchoring member disposed below the girder; having 2. A formwork structure according to claim 1, wherein a lower end of the tendon is fixed to the fixing member.

3. The Mellan material has a cylindrical main girder along the bridge axis direction, The inside of the main girder is filled with filler concrete, 2. The formwork structure according to claim 1, wherein the tendon is passed through a tube disposed within the main girder, and an upper end of the tendon is fixed to an upper surface of the main girder.

4. The formwork structure according to claim 1, characterized in that a cylindrical body surrounding the bundle material is provided between the Mellan material and the bottom formwork.

Images