Reinforcing bar unit for projection of shinkansen roadbed, and method and device for manufacturing the same

Abstract

PURPOSE: To provide a reinforcing bar unit for projecting concrete of a Shinkansen roadbed, which does not affect the mechanical properties of a structural part in the reinforcing bar when a part of the reinforcing bar for projecting concrete is fixed to an anchor bar by arc welding, eliminates a wasteful space when storing or transporting a plurality of reinforcing bar units stacked up and down, and reduces work at a construction site and improves efficiency, and a method and device for manufacturing the same.CONSTITUTION: A reinforcing bar unit for projecting a Shinkansen roadbed used when constructing projecting concrete for the Shinkansen roadbed, wherein one or a plurality of ring-shaped non-structural bars which are not necessary in terms of specification, design, or structure are joined to respective laterally extending portions in a plurality of L-shaped bars by spot welding, and a method and device for manufacturing the reinforcing bar unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a reinforcing bar unit for a projection of a Shinkansen roadbed, and a method and apparatus for manufacturing the same. [Background technology]

[0002] Figure 6 is a diagram showing a conventional concrete roadbed (Shinkansen roadbed) that supports the track slabs of a Shinkansen. As shown in Figure 6, in the conventional Shinkansen roadbed, cylindrical concrete protrusions 32 (hereinafter sometimes simply referred to as "protrusions") are provided at predetermined intervals on a sub-concrete basement 31 (see reference numerals 31 and 32 in Figure 6(c)). These concrete protrusions 32 are formed or installed on the sub-concrete basement 31 at predetermined intervals (for example, 5 m intervals) along the direction in which the rails are laid. When multiple concrete plates that will become track slabs are installed on the Shinkansen roadbed, these cylindrical concrete protrusions 32 are used to horizontally position and hold each concrete plate (track slab).

[0003] When constructing the lower concrete 31 and the protruding concrete 32, the necessary rebars are placed before pouring the concrete. Figure 6(a) is a plan view showing rebars used when constructing the protruding concrete 32, which are ordinary rebars for the protruding concrete 32 that are installed on the lower concrete 31 at intervals of, for example, 5 m, and Figure 6(b) is a plan view showing rebars for the protruding concrete that are installed at special positions in the lower concrete 31, for example, at joints every 20 m.

[0004] 6(c) is a side cross-sectional view showing the state in which the protruding concrete 32 shown in FIG. 6(a) is installed in the sub-concrete 31 of the conventional Shinkansen roadbed as described above. As shown in FIG. 6, reinforcing bars consisting of, for example, eight L-shaped bars (structural bars) 33 and six ring bars (ring-shaped structural bars) 34 are embedded in the sub-concrete 31 and the protruding concrete 32. Note that both the L-shaped bars 33 and the ring-shaped structural bars 34 are structural bars required in terms of the specifications, design, and structure of the reinforcing bars for the protruding concrete.

[0005] Before pouring concrete, workers at the construction site install such rebars by bundling, for example, eight L-shaped rebars 33 and six ring-shaped structural rebars 34 together, or by previously installing a unit of rebars at a factory, for example, by arc welding one ring-shaped structural rebar 34 (one of the six in total) to the lower part of the vertically extending part 33a of each of the eight L-shaped rebars 33, and then bringing the unit to the construction site, where workers then install the remaining five ring-shaped structural rebars 34 (five of the six in total) by bundling them to each of the L-shaped rebars 33. In the figure, reference symbol 33b indicates the horizontally extending part of the L-shaped rebar 33.

[0006] Next, Figure 7(a) is a plan view showing an example of a conventional reinforcing bar unit manufactured in advance in a factory by arc welding, for example, one ring-shaped structural bar 34 to a part of each vertically extending portion 33a of eight L-shaped bars 33, and Figure 7(b) is a side view of the same.

[0007] 8 is a perspective view showing an example of a conventional reinforcing bar unit formed in advance in a factory by arc welding, for example, one ring-shaped structural bar 34 to the lower portion of the vertically extending portion 33a of, for example, eight L-shaped bars 33. In the conventional reinforcing bar unit shown in FIG. 8, each L-shaped bar 33 is composed of a portion 33a extending vertically in the figure and a portion 33b extending horizontally in the figure. In the conventional example shown in Figure 8, a total of eight L-shaped reinforcements 33 are arranged so that their horizontally extending portions 33b extend radially at equal intervals from each other, and the lower portions of each of their vertically extending portions 33a (portions approximately 1 cm to several cm above the upper surface of the horizontally extending portions 33b) are joined to one ring-shaped structural reinforcement 34 by arc welding (note that approximately six ring-shaped structural reinforcements 34 are fixed to each of the vertically extending portions 33a, but for example, only one ring-shaped structural reinforcement 34 is fixed in advance by arc welding at the factory, and the remaining five ring-shaped structural reinforcements 34, for example, are fixed to each of the vertically extending portions 33a by bundling at the construction site).

[0008] Furthermore, the ring-shaped structural reinforcement 34, which is fixed to each of the vertically extending portions 33a by arc welding at the factory or by bundling on site, has been considered a structural reinforcement required in terms of specifications, design, and structure as a reinforcing bar for protruding concrete. In other words, when constructing the protruding concrete at a construction site, it is required in terms of specifications, design, and structure to fix multiple points of each of the vertically extending portions 33a of the eight L-shaped reinforcements 33 to the ring-shaped structural reinforcement 34.

[0009] In contrast, fixing each of the portions 33b of each L-shaped reinforcement 33 extending laterally downward as shown in Figure 7(b) to the ring-shaped structural reinforcement 34 is not required, at least in terms of specifications, design, or structure as a protruding concrete reinforcing bar.

[0010] In a conventional reinforcing bar unit, as shown in Figures 7 and 8, the lower portion of each vertically extending portion 33a of the L-shaped reinforcement 33 is fixed to, for example, one ring-shaped structural reinforcement 34 by arc welding in advance in a factory.After the unit is brought from the factory to the construction site, a portion of each vertically extending portion 33a of each L-shaped reinforcement 33 (for example, the portion above the position of the one ring-shaped structural reinforcement 34 that was previously joined in the factory) is fixed by a worker to, for example, five ring-shaped structural reinforcements by bundling.

[0011] Next, Figure 9(a) is a side cross-sectional view showing the state when the above-mentioned normal type reinforcing bar unit for protruding concrete is embedded in the lower concrete 31. In contrast to this, Figure 9(b) is a side cross-sectional view showing the state when a threaded reinforcing bar unit, in which the vertically extending portion of the L-shaped bar 33 is divided into a vertical portion 33a continuing from the horizontally extending portion 33b and the remaining portion 33c, with the latter portion 33c being separated and removed, is embedded in the lower concrete 31. When constructing using the threaded reinforcing bar unit shown in Figure 9(b), first, a reinforcing bar unit consisting of the L-shaped bar 33 (the part from which the separate divided part 33c has been separated and removed) and the ring-shaped structural bar 34 is placed, and concrete is poured to form the lower concrete part 31.After that, the male screw 33e formed at the lower end of the separate divided and separated part 33c is screwed into the female screw socket 33d installed at the upper end of the vertical part 33a that is continuous with the horizontally extending part 33b, thereby fixing the separate divided and separated part 33c to the vertical part 33a and completing the reinforcing bar unit. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] Patent Publication No. 2021-143457 Summary of the Invention [Problem to be solved by the invention]

[0013] However, with regard to such conventional protruding concrete for roadbeds, first, at the construction site of the lower concrete and the protruding concrete, before pouring the concrete, some of the reinforcing bars for the protruding concrete assembled with the ties etc. are fixed by arc welding to anchor bars (positioning bars) fixed to the bottom side (invert concrete etc.) (as a result, the reinforcing bars for the protruding concrete are slightly suspended in the air from the bottom side), but there is a problem in that the high heat generated by the arc welding performed to fix them to the anchor bars at this time may affect the mechanical properties of the structural bars that are necessary for the specifications, design or structure that make up the reinforcing bars for the protruding concrete.

[0014] In addition, instead of manually bundling multiple L-shaped bars and multiple ring bars at the construction site, some methods involve arc welding the vertically extending portions of multiple L-shaped bars and one ring bar (a structural bar required for specifications, design, or structure) together in advance at a factory to form a unit, and then transporting the reinforcing bar unit manufactured in this way to the construction site (where the other five ring bars are then bundled and fixed to the vertically extending portions of the multiple L-shaped bars).However, when such reinforcing bar units are transported or stored stacked one on top of the other, gaps will exist between the multiple reinforcing bar units stacked one on top of the other (because the ring bars are fixed to the vertically extending portions of the L-shaped bars), which creates the problem of a lot of wasted space in the vertical direction when transporting and storing multiple reinforcing bar units.

[0015] Furthermore, as mentioned above, when the vertically extending portions of multiple L-shaped reinforcements and a single ring reinforcement (structural reinforcement required for specifications, design, or structure) are arc-welded together in advance in a factory to form a unit, there was a problem in that the high heat generated during the arc welding (arc discharge can sometimes reach temperatures exceeding 20,000 degrees) could affect the mechanical properties of each of the reinforcing bars.

[0016] Furthermore, at conventional construction sites for protruding concrete, workers often manually tied all of the L-shaped reinforcement and ring reinforcement together to assemble the rebar for the protruding concrete. However, this made the work on site cumbersome, reducing construction efficiency, and there were problems with variations in the accuracy of the tying due to differences in the skill levels of individual workers.

[0017] The present invention was made in response to the problems with the reinforcing bars or reinforcing bar units used in the construction of conventional protruding concrete for Shinkansen roadbeds. The present invention aims to provide a reinforcing bar unit for protruding Shinkansen roadbeds, and a manufacturing method and device for the same, which can prevent the mechanical properties of the structural parts of the reinforcing bars (or reinforcing bar units) (structural bars required for the specifications, design, or structure of the reinforcing bars or reinforcing bar units) from being affected by the high heat generated during arc welding performed to join them to anchor bars fixed to the bottom surface (such as invert concrete) before concrete is poured at the construction site for the protruding concrete.

[0018] Another object of the present invention is to provide a reinforcing bar unit for protrusions in Shinkansen roadbeds, as well as a manufacturing method and device for the same, which, when multiple L-shaped bars or the like are unitized in advance at a factory as described above and these unitized reinforcing bars are transported or stored at a construction site, eliminates gaps between the top and bottom of multiple reinforcing bar units when they are stacked one on top of the other, thereby eliminating wasted vertical space for transporting and storing multiple reinforcing bar units.

[0019] Another object of the present invention is to provide a reinforcing bar unit for protrusions in Shinkansen roadbeds, as well as a manufacturing method and device for the same, which can prevent the high heat generated during welding from affecting the mechanical properties of the structural reinforcing bars of the reinforcing bar unit when arc welding is performed to fix and unitize the L-shaped bars and ring bars (both of which are structural reinforcing bars required for specifications, design, or structure) when multiple L-shaped bars, etc. are unitized in advance at a factory and the unitized reinforcing bars are transported to a construction site, as described above.

[0020] Another object of the present invention is to provide a rebar unit for protrusions on Shinkansen roadbeds, as well as a manufacturing method and device for the same, which can significantly reduce the amount of work required by workers at the construction site and improve work efficiency, compared to the conventional method in which workers manually bundled all L-shaped reinforcements and ring reinforcements at the construction site to assemble rebar for protruding concrete, and which can suppress variations in binding accuracy due to differences in the skill level of individual workers, etc.

[0021] Another object of the present invention is to provide a manufacturing method and apparatus that can efficiently and accurately manufacture the above-mentioned reinforcing bar units for projections in Shinkansen roadbeds. [Means for solving the problem]

[0022] In order to solve the above problems, the reinforcing bar unit for protrusions in Shinkansen roadbeds according to the present invention is a reinforcing bar unit for protrusions in Shinkansen roadbeds used when constructing protruding concrete in Shinkansen roadbeds, characterized in that ring-shaped non-structural bars that are not necessary from a specification, design, or structural perspective are joined by spot welding to each of the horizontally extending parts of multiple L-shaped bars, and the multiple L-shaped bars are held and fixed in a state where they are positioned and arranged at predetermined intervals from each other.

[0023] In addition, the manufacturing method of a reinforcing bar unit for a protrusion of a Shinkansen roadbed according to the present invention is characterized by comprising an arrangement step in which a frame body is used to position and arrange a plurality of L-shaped bars so that each of their laterally extending portions extends radially at a predetermined interval from each other; an abutting step in which ring-shaped non-structural bars that are not necessary in terms of specifications, design, or structure are abutted against each of the laterally extending portions of the plurality of L-shaped bars; and a joining step in which each intersection of the laterally extending portions of the abutted L-shaped bars and the ring-shaped non-structural bars is joined by spot welding.

[0024] The manufacturing device for reinforcing bar units for projections in Shinkansen roadbeds according to the present invention comprises a first frame body that positions and holds a plurality of L-shaped bars so that the tips of their vertically extending portions are directed downward and so that their horizontally extending portions extend radially at predetermined intervals from one another; a second frame body that positions and holds ring-shaped non-structural bars that are not necessary for the specifications, design, and structure of the reinforcing bar unit so that they abut against the horizontally extending portions of the L-shaped bars; and a second frame body that holds the horizontally extending portions of the L-shaped bars held by the first frame body and the second frame body. and a rotating part that rotates the first and second frame bodies by a predetermined angle to move the abutment portion between the horizontally extending portion of one of the plurality of L-shaped reinforcements and the ring-shaped non-structural reinforcement, which abuts the ring-shaped non-structural reinforcement but has not yet been spot-welded, to the position of the spot welding part, and the rotation and spot welding operations are repeated sequentially until all of the abutment portions have been joined by spot welding.

[0025] In addition, the manufacturing method of a reinforcing bar unit for a protrusion in a Shinkansen roadbed according to the present invention involves using a first frame to position and hold a plurality of L-shaped bars so that the tips of their vertically extending portions are directed downward and so that their horizontally extending portions extend radially at equal distances from one another, and using a second frame to position and hold ring-shaped non-structural bars that are not necessary for the design or structure so that they abut against the horizontally extending portions of the L-shaped bars, spot welding each of these abutting portions using spot welding parts, rotating the horizontally extending portion of the L-shaped bars by a predetermined angle using a rotating part so that a horizontally extending portion of one of the plurality of L-shaped bars that has not yet been spot welded is moved to the position of the spot welding part and spot welding is performed, and the above-mentioned rotation and spot welding operations are repeated sequentially by a control unit or the like until the spot welding is performed on all of the abutting portions.

[0026] Furthermore, in the reinforcing bar unit for protrusions in Shinkansen roadbeds according to the present invention, each of the horizontally extending portions of the multiple L-shaped bars may be joined by spot welding to a ring-shaped non-structural bar that is not necessary for the specifications, design, and structure of the reinforcing bar unit, and each of the vertically extending portions of the L-shaped bars may be joined by spot welding to a ring-shaped structural bar that is necessary for the specifications, design, and structure of the reinforcing bar unit. [Effects of the Invention]

[0027] In the present invention, a reinforcing bar unit is manufactured by spot welding each intersection (each abutment portion) of each of the horizontally extending portions of the multiple L-shaped bars, which are arranged radially at a predetermined interval from each other, and a ring-shaped non-structural bar that is not necessary from the specifications, design, or structure perspective. Therefore, when using such a reinforcing bar unit of the present invention, before pouring concrete at the construction site of the protruding concrete, a part of the reinforcing bar (or reinforcing bar unit) is secured by arc welding to an anchor bar secured to the bottom side (such as invert concrete) (as a result, the reinforcing bar or reinforcing bar unit is slightly raised from the bottom side), and the part of the reinforcing bar (or reinforcing bar unit) secured to the anchor bar by arc welding can be a ring-shaped non-structural bar secured to each of the horizontally extending parts (rather than the horizontally extending parts of L-shaped bars as in the conventional case). This prevents the mechanical properties of the structural parts of the reinforcing bar unit (structural bars required for the specifications, design, or structure of the reinforcing bar or reinforcing bar unit) from being affected by the high heat generated by the arc welding performed to join them to the anchor bars (in contrast to such arc welding, electric resistance welding, including spot welding, is permitted in JIS G 3551 for use in the manufacture of welded wire mesh or reinforcing bar grids because it has little effect on the mechanical properties of the reinforcing bar).

[0028] That is, when constructing protruding concrete at a construction site, before pouring the concrete, it is necessary to fix the anchor rebar fixed to the bottom side (such as invert concrete) to a part of the reinforcing bar unit by arc welding so that the reinforcing bar unit is positioned a predetermined distance above the bottom side (see, for example, FIG. 3(b) . Note that, at construction sites, arc welding is actually used to fix reinforcing bars or reinforcing bar units to anchor rebars). However, since arc welding is a welding method that heats and melts metal to join them, fixing anchor rebars to L-shaped rebars as structural rebars by arc welding could affect the mechanical properties of the L-shaped rebars as structural rebars (see reference numeral 1 in FIGS. 6 to 9 ). In contrast, in the first embodiment, as described above, a part of the ring-shaped non-structural rebars that are not required for the specifications, design, and structure is joined to the anchor rebars (see FIG. 3) fixed to the bottom side (such as invert concrete) by arc welding. This prevents the mechanical properties of the structural parts (structural rebars) in the reinforcing bar unit for protruding concrete from being affected by the high heat generated during the arc welding. In particular, in the present invention, when a plurality of ring-shaped non-structural reinforcements with different radii are joined by spot welding to each of the horizontally extending portions of the plurality of L-shaped reinforcements, the location to join with the anchor reinforcement fixed to the bottom side (invert concrete, etc.) can be selected from among the plurality of ring-shaped non-structural reinforcements, making it possible to more efficiently and easily fix a portion of the protruding concrete rebar to the anchor reinforcement by arc welding.

[0029] Furthermore, in the present invention, as described above, reinforcing bar units are manufactured by spot welding ring-shaped non-structural reinforcements, which are not necessary from a specification, design, or structural perspective, to each horizontally extending portion of each L-shaped reinforcement.Therefore, when multiple reinforcing bar units are stacked one on top of the other for transport or storage, there is no gap between the top and bottom of each reinforcing bar unit when stacked one on top of the other (because the ring-shaped non-structural reinforcements are not joined to each vertically extending portion of each L-shaped reinforcement, but to each horizontally extending portion), and vertical space is not wasted when transporting or storing multiple reinforcing bar units.

[0030] Furthermore, in the present invention, in order to unitize multiple L-shaped reinforcements together in advance at the factory, instead of the conventional method of joining the vertically extending portions of multiple L-shaped reinforcements to ring reinforcements as structural reinforcements by arc welding (which had the problem that the high heat generated during arc welding affected the mechanical properties of the structural reinforcement), the horizontally extending portions of multiple L-shaped reinforcements are joined to the ring-shaped non-structural reinforcement by spot welding, thereby preventing the inconvenience of the high heat generated during welding affecting the mechanical properties of the structural reinforcement.

[0031] Furthermore, in the present invention, as described above, reinforcing bar units are manufactured by spot welding ring-shaped non-structural reinforcements, which are not necessary for the specifications, design, or structure of the reinforcing bar unit, to each of the horizontally extending parts of each L-shaped reinforcement.This significantly reduces the amount of work required by workers at the construction site, improving work efficiency, compared to when workers at the construction site for protruding concrete manually tie together and assemble all of the non-unitized L-shaped reinforcements and ring reinforcements.

[0032] In addition, in the manufacturing method or apparatus of the present invention, a first frame body positions and holds multiple L-shaped reinforcements so that the tips of each of their vertically extending portions are facing downward and so that each of their horizontally extending portions extends radially at equal distances from each other, and a second frame body positions and holds ring-shaped non-structural reinforcements that are not necessary for the specifications, design, or structure of the reinforcing bar unit so that they abut against the horizontally extending portions of the L-shaped reinforcements, and each of these abutting portions is spot welded using a spot welding portion, and a rotating portion is used to rotate the horizontally extending portions of the multiple L-shaped reinforcements by a predetermined angle to move a horizontally extending portion of one of the multiple L-shaped reinforcements that has not yet been spot welded to the position of the spot welding portion and spot weld it.When this operation is repeated until all of the abutting portions have been spot welded by a control unit, etc., spot welding of each of the abutting portions between the multiple L-shaped reinforcements and the non-structural reinforcements can be performed extremely efficiently and accurately.

[0033] Furthermore, in the present invention, not only are ring-shaped non-structural reinforcement bars, which are not necessary for the specifications, design, and structure of the reinforcing bar unit, joined by spot welding to each horizontally extending portion of multiple L-shaped reinforcement bars, but ring-shaped structural reinforcement bars, which are necessary for the specifications, design, and structure of the reinforcing bar unit, are joined by spot welding to each vertically extending portion of the L-shaped reinforcement bars.By using the non-structural reinforcement bars as the parts fixed to the anchor reinforcement by arc welding as described above, the structural parts of the reinforcing bar unit are prevented from being affected by the high heat during arc welding, and the reinforcing bar unit as a whole is more resistant to breakage during transportation and installation than when non-structural reinforcement bars are simply joined to each horizontally extending portion of multiple L-shaped reinforcement bars (note that when doing this, the effect of eliminating gaps between the top and bottom of each reinforcing bar unit when stacked one on top of the other for transportation or storage cannot be achieved). [Brief explanation of the drawings]

[0034] [Figure 1] 1(a) is a plan view illustrating a reinforcing bar unit for a protruding concrete of a Shinkansen roadbed according to a first embodiment of the present invention and a manufacturing method thereof, and FIG. 1(b) is a side view thereof. [Figure 2] This is an oblique view showing a reinforcing bar unit manufactured by spot welding each intersection of each horizontally extending portion of multiple L-shaped bars arranged at a predetermined interval from each other and a ring-shaped non-structural bar that is not necessary for the specifications, design, and structure of the reinforcing bar unit, in accordance with this embodiment 1. [Figure 3] 10A and 10B are diagrams for explaining the configuration and effects of the protruding concrete reinforcing bar unit according to the second embodiment. [Figure 4] 10(a) is a plan view for explaining a manufacturing method of a protruding concrete reinforcing bar unit according to a third embodiment, and FIG. 10(b) is a side view thereof. [Figure 5] 10(a) is a plan view illustrating a method for manufacturing a protruding concrete reinforcing bar unit according to a fourth embodiment, and FIG. 10(b) is a side view thereof. [Figure 6](a) is a plan view showing the rebars used when placing protruding concrete on the lower concrete of a conventional roadbed, (b) is a plan view showing the rebars for the protruding concrete that are installed at the end of a concrete slab with a total length of, for example, 20 m that makes up the lower concrete of the conventional roadbed, and (c) is a cross-sectional view showing the state in which the protruding concrete has been placed on the lower concrete of a conventional Shinkansen roadbed. [Figure 7] (a) is a plan view showing an example of a conventional reinforcing bar unit, which is formed in advance in a factory by arc welding a single ring-shaped structural bar to a portion of the vertically extending portion of multiple L-shaped bars, and (b) is a side view of the same. [Figure 8] FIG. 1 is a perspective view showing an example of a conventional reinforcing bar unit that is formed in advance in a factory by joining a single ring-shaped structural bar to a portion of the vertically extending portion of multiple L-shaped bars by arc welding to form a unit. [Figure 9] (a) is a cross-sectional view showing the state when the lower part of a conventional type reinforcing bar unit for use in conventional protruding concrete is embedded in the underlying concrete, and (b) is a cross-sectional view showing the state when the lower part of a threaded type reinforcing bar unit for conventional protruding concrete (a type in which part of the vertically extending part of the L-shaped bar is divided and separated as a separate piece, and this separate part is attached and fixed with screws after the underlying concrete has been poured) is embedded in the underlying concrete. DETAILED DESCRIPTION OF THE INVENTION

[0035] [Embodiment 1] Figure 1(a) is a plan view for explaining a protruding concrete reinforcing bar unit for a Shinkansen roadbed and its manufacturing method according to embodiment 1 of the present invention, (b) is a side view thereof, and Figure 2 is an oblique view of the protruding concrete reinforcing bar unit.

[0036] In Figure 1(b), 1 denotes an L-shaped reinforcement consisting of a portion 1a extending in the vertical direction of the figure and a portion 1b extending in the horizontal direction of the figure; 2 denotes a ring-shaped non-structural reinforcement that is a ring-shaped reinforcement formed in a circular shape and abuts against the upper surface of the horizontally extending portion 1b of the L-shaped reinforcement 1 (as will be described later, this is a ring-shaped non-structural reinforcement that is not necessary in terms of the specifications, design, and structure of the reinforcing bar unit); and 3 denotes a ring-shaped non-structural reinforcement formed with a radius that is a predetermined length larger than the ring-shaped non-structural reinforcement 2 (as above, this is a ring-shaped non-structural reinforcement that is not necessary in terms of the specifications, design, and structure of the reinforcing bar unit), and abuts against the upper surface of the horizontally extending portion 1b of the L-shaped reinforcement 1, as with the ring-shaped non-structural reinforcement 2. In this embodiment 1, there are a total of eight L-shaped reinforcements, and the horizontally extending portions 1b are arranged so that they extend radially at predetermined intervals from each other.

[0037] In Figure 1, reference numeral 11 denotes a base used when manufacturing a reinforcing bar unit by joining each horizontally extending portion 1b of each L-shaped bar 1 to each of the non-structural bars 2 and 3 by spot welding, and reference numeral 12 denotes a vertical support provided on the base 11. The vertical support 12 is used to position and hold the vertically extending portion 1a of each L-shaped bar 1 in the vertical direction in Figure 1(b). One vertical support 12 is provided for each of the eight L-shaped bars 1.

[0038] 1, reference numeral 13 denotes a horizontal receiving pedestal provided on the base 11. This horizontal receiving pedestal 13 is used to position the laterally extending portion 1b of the L-shaped reinforcement 1 at a predetermined height (a height sufficient to form a space below the laterally extending portion 1b where an electrode 14 for spot welding, which will be described later, can be inserted) above the surface of the base 11. The horizontal receiving pedestal 13 is also provided for each of the eight L-shaped reinforcement 1s.

[0039] 1, 14 is an electrode inserted and placed below the tip of the laterally extending portion 1b of the L-shaped reinforcing bar 1 (in the space between the base 11), and 15 is an electrode placed above a portion of the nonstructural reinforcing bar 3 (the portion abutting the laterally extending portion 1b of the L-shaped reinforcing bar 1). During spot welding, the electrodes 14 and 15 are placed so as to sandwich the L-shaped reinforcing bar 1 and the nonstructural reinforcing bar 2 from above and below. Electricity is passed between the electrodes 14 and 15, and they are pressed toward each other by a clamping device (not shown), thereby performing spot welding. This joins the abutting portions of the L-shaped reinforcing bar 1 and the nonstructural reinforcing bar 2.

[0040] This spot welding operation, including the clamping operation, is performed sequentially for each contact point between the eight L-shaped bars 1 and the non-structural bars 2 and 3, thereby manufacturing the reinforcing bar unit according to Embodiment 1. Reference numeral 2 denotes a ring-shaped non-structural bar with a radius smaller than the non-structural bars 3 by a predetermined length, and is joined to the horizontally extending portion 1b of the L-shaped bar 1, just like the non-structural bars 3. Figure 2 is a perspective view showing the reinforcing bar unit manufactured in this manner, in which the horizontal portions 1b of the eight L-shaped bars 1 are joined to the intersections (contact points) of the ring-shaped non-structural bars 2 and 3 by spot welding.

[0041] As described above, according to the first embodiment, before concrete is poured at the construction site of the protruding concrete, a portion of the reinforcing bar unit is arc-welded to anchor bars 40 fixed to the bottom surface (e.g., invert concrete) 30 (so that the reinforcing bar unit is raised from the bottom surface; see FIG. 3 ). Instead of the portions of the reinforcing bar unit that are arc-welded to the laterally extending portions 1b of the L-shaped bar 1 as in the conventional method, the portions of the reinforcing bar unit that are arc-welded to the laterally extending portions 1b of the L-shaped bar 1 can be either or both of the ring-shaped non-structural bars 2 and 3 fixed to the laterally extending portions 1b of the L-shaped bar 1. This prevents the mechanical properties of the structural portions of the reinforcing bar unit (structural bars required for the specifications, design, or structure of the reinforcing bar unit) from being affected by the high heat generated by arc welding to join the anchor bars 40. The effects of the first embodiment are similar to those of the second embodiment described below with reference to FIG. 3 , and therefore will not be described in detail here.

[0042] Furthermore, in this embodiment 1, as described above, each reinforcing bar unit is constructed by spot welding the ring-shaped non-structural bars 2, 3 to each of the horizontally extending portions 1b of each L-shaped bar 1, so when multiple reinforcing bar units are stacked one on top of the other for transporting or storing, gaps between the stacked reinforcing bar units can be eliminated, and space wasted due to such gaps can be eliminated when transporting or storing multiple reinforcing bar units.

[0043] In addition, in this embodiment 1, when multiple L-shaped reinforcements 1 are unitized in advance at a factory, unlike the conventional method of joining the vertically extending portions 1a of the multiple L-shaped reinforcements 1 to the ring-shaped structural reinforcement 34 (see Figures 6 to 9) by arc welding (which had the potential for the high heat generated during arc welding to affect the mechanical properties of the ring-shaped structural reinforcement), the horizontally extending portions 1b of the multiple L-shaped reinforcements 1 to the ring-shaped non-structural reinforcement 2, 3 are joined by spot welding, thereby eliminating the inconvenience of the heat generated during the joining affecting the mechanical properties of the structural reinforcement in the reinforcing bar unit.

[0044] Furthermore, in this embodiment 1, as described above, the ring-shaped non-structural reinforcements 2, 3 are spot-welded to each of the horizontally extending portions 1b of each of the L-shaped reinforcements 1 to form a reinforcing bar unit. Therefore, compared to the conventional case where workers manually bind, assemble and arrange all of the L-shaped reinforcements and ring reinforcements at a construction site for protruding concrete, manual work at the construction site can be significantly reduced, work efficiency can be improved and variations in binding accuracy due to differences in the skill level of individual workers can be suppressed.

[0045] In particular, in this embodiment 1, a reinforcing bar unit is manufactured by spot welding a plurality of ring-shaped non-structural reinforcements 2, 3 having different radii to each of the horizontally extending portions 1b of the plurality of L-shaped reinforcements 1. Therefore, when workers at the construction site join a portion of the reinforcing bar unit to the anchor reinforcement 40 (see Figure 3) by arc welding, they can arbitrarily select the portion to be joined by arc welding from one or both of the plurality of non-structural reinforcements 2, 3. Therefore, compared to the case where only one non-structural reinforcement is fixed to each of the horizontally extending portions 1b of the plurality of L-shaped reinforcements 1 to form the reinforcing bar unit (the case shown in Figures 3 to 5 described below), the work of fixing a portion of the reinforcing bar unit to the anchor reinforcement 40 by arc welding can be performed more efficiently and easily.

[0046] [Embodiment 2] Next, a second embodiment of the present invention will be described with reference to Figure 3. The configuration of the second embodiment is basically the same as that of the first embodiment described above with reference to Figures 1 and 2, but differs in the following respects: First, in the first embodiment described above with reference to Figures 1 and 2, a reinforcing bar unit is formed by fixing two ring-shaped nonstructural bars 2 and 3 to the laterally extending portion 1b of the L-shaped bar 1, but in the second embodiment, one ring-shaped nonstructural bar 4 is fixed to the laterally extending portion 1b of the L-shaped bar 1, and one ring-shaped structural bar 34 is fixed to the lower portion of the vertically extending portion 1a of the L-shaped bar 1 (a portion relatively close to the laterally extending portion 1b), thereby forming a reinforcing bar unit.

[0047] Referring to FIG. 3, the effect of the reinforcing bar unit according to the second embodiment will be described below, in particular, the effect of preventing the mechanical properties of the structural parts of the reinforcing bar unit from being affected by the high heat generated by arc welding performed for joining the reinforcing bar unit to the anchor bar 40. According to the second embodiment, before concrete is poured at the construction site of the protruding concrete, when a portion of the reinforcing bar unit is arc-welded to anchor bars 40 fixed to the bottom side (such as invert concrete) 30 (as a result, the reinforcing bar unit is slightly raised from the bottom side), the portion of the reinforcing bar unit to be arc-welded is not the ring-shaped structural bars 34 (see also reference numeral 34 in FIGS. 6 to 9 ) fixed to each longitudinally extending portion 1a of the L-shaped bar 1 as in the conventional method, but the ring-shaped non-structural bars 4 fixed to each transversely extending portion 1b of the L-shaped bar 1. This prevents the mechanical properties of the structural portions of the reinforcing bar unit (structural bars required for the specifications, design, or structure of the reinforcing bar unit) from being affected by the high heat generated by arc welding to join the anchor bars 40. These effects are described in detail below.

[0048] As mentioned above, before pouring concrete for projecting concrete construction, anchor bars 40 fixed to the bottom side (invert concrete, etc.) 30 are fixed to part of the reinforcing bars or reinforcing bar units by arc welding (as a result, the reinforcing bars or reinforcing bar units are positioned so that they are raised a specified distance above the bottom side), but conventionally, at this time, the structural parts of the reinforcing bars or reinforcing bar units (for example, L-shaped reinforcing bars as structural reinforcing bars) have been fixed to the anchor bars 40 by arc welding (as a result, there is a possibility that the mechanical properties of the structural parts of the reinforcing bars or reinforcing bar units may be affected by the high heat generated during arc welding). In contrast, when construction is carried out using the reinforcing bar unit of this embodiment 2, as shown in Figure 3, a portion of the ring-shaped non-structural reinforcement 4 in the reinforcing bar unit of this embodiment 2, which is not necessary in terms of the specifications, design, and structure of the reinforcing bar unit, is joined by arc welding to anchor reinforcement 40 fixed to the bottom side (invert concrete, etc.) 30, thereby fixing the reinforcing bar unit to the anchor reinforcement 40 (as a result, the reinforcing bar unit is positioned so that it floats a predetermined distance (see symbol α in Figure 3(b)) above the bottom side 30, as in the conventional case).

[0049] That is, in the past, a reinforcing bar unit was fixed to the anchor bars 40 by arc welding a portion of the L-shaped bars 1 (see Figures 6 to 9), which are structural materials required for the specifications, design, and structure of the reinforcing bar unit (note that when workers at construction sites fix reinforcing bar units to anchor bars 40, they actually use arc welding). However, with this conventional method, arc welding is a welding method in which metal is heated and melted to join, and this could affect the mechanical properties of the ring-shaped structural bars 34 that serve as structural bars in the reinforcing bar unit (in contrast to this type of arc welding, electric resistance welding, including spot welding, is permitted in JIS G 3551 to be used in the manufacture of welded wire mesh or reinforcing bar grids because it has little effect on the mechanical properties of the reinforcing bars).

[0050] In contrast to this, in the case of the second embodiment, a part of the ring-shaped non-structural reinforcement 4 (the ring-shaped non-structural reinforcement 4 that is not necessary in terms of the specifications, design, and structure of the reinforcing bar unit) is fixed to the anchor reinforcement 40 (see FIG. 3) by arc welding, thereby fixing the reinforcing bar unit to the anchor reinforcement 40. Therefore, in the case of the second embodiment, when a part of the reinforcing bar unit is fixed to the anchor reinforcement 40 by arc welding before pouring concrete to construct the protruding concrete, the part fixed to the anchor reinforcement 40 by arc welding can be a part of the ring-shaped non-structural reinforcement 4 in the reinforcing bar unit, so that it is possible to prevent the mechanical properties of the structural part (structural reinforcement) in the reinforcing bar unit from being affected by the high heat generated by arc welding of the contact part between the anchor reinforcement 40 and the ring-shaped non-structural reinforcement 4.

[0051] In particular, in this embodiment 2, not only are ring-shaped non-structural reinforcements 4, which are not necessary in terms of the specifications, design, and structure of the reinforcing bar unit, joined by spot welding to each of the horizontally extending portions 1b of the eight L-shaped reinforcements 1, but ring-shaped structural reinforcements 34, which are necessary in terms of the specifications, design, and structure of the reinforcing bar unit, are joined by spot welding to each of the vertically extending portions 1a of the L-shaped reinforcements 1.As a result, by using the non-structural reinforcements 34 as the portions fixed to the anchor reinforcements 40 by arc welding as described above, the structural portions of the reinforcing bar unit are prevented from being affected by the high heat during arc welding, and the entire reinforcing bar unit is more likely to break during transportation and binding operations than if non-structural reinforcements were simply joined to each of the horizontally extending portions 1b of the L-shaped reinforcements 1 (since the eight L-shaped reinforcements 1 are also fixed by the ring-shaped structural reinforcements 34). In addition, in this embodiment 2, since ring-shaped structural reinforcement 34 is joined to each vertically extending portion 1a of the L-shaped reinforcement 1, the effect of eliminating gaps between the top and bottom of each steel bar unit stacked one on top of the other for transportation or storage, as described in embodiment 1, does not occur.

[0052] [Embodiment 3] 4(a) is a plan view illustrating a manufacturing method of a protrusion reinforcing bar unit for a Shinkansen roadbed according to a third embodiment of the present invention, and FIG. 4(b) is a side view thereof. In the manufacturing method according to the third embodiment, as shown in FIG. 4(b), a total of eight L-shaped bars 1 are first arranged upside down from the state in which they are used during the construction of protrusion concrete (with the tip of each of the vertically extending portions 1a of the L-shaped bars 1 extending downward), i.e., with the tip of each vertically extending portion 1a of each L-shaped bar 1 facing downward. Then, each L-shaped bar 1 is positioned and held in place by frames 21 and 22 for uniformly arranging the horizontally extending portions 1b of each L-shaped bar 1 at predetermined intervals and radially arranged, and a frame 23 for vertically arranging the vertically extending portions 1a.

[0053] As shown in Figure 4, the frame 24 positions and holds each of the non-structural reinforcements 4 so that the ring-shaped non-structural reinforcements 4 come into contact with the upper surface (the lower surface in Figure 4(b)) of each laterally extending portion 1b of each of the L-shaped reinforcements 1 during construction. The frame members 21 to 24 are also configured to be rotatable together in the horizontal direction by a central rotation axis 25 in the figure.

[0054] As shown in Figure 4(b), the tip of each vertically extending portion 1a of each L-shaped reinforcement 1 faces downward, and the bottom surface of each horizontally extending portion 1b abuts against the top surface of the nonstructural reinforcement 4. In this embodiment 3, in this state, the clamping devices 16a and 16b clamp the electrodes 14, 15, from above and below, respectively, to press the abutted portions and pass current between the electrodes 14 and 15 to spot weld them. The rotating shaft 25 is then rotated to rotate the L-shaped reinforcement 1 and the nonstructural reinforcement 4 by a predetermined angle horizontally, and the abutting portions of the L-shaped reinforcement 1 and the nonstructural reinforcement 4 that have not yet been spot welded are moved between the clamping devices 16a and 16b, where the spot welding is performed. Furthermore, these rotational and spot welding operations are repeated in sequence by a control unit (not shown) configured by a microcomputer or the like, or manually, until the spot welding is performed on all of the contact portions between each of the eight L-shaped reinforcements 1 and the non-structural reinforcements 4. In this way, the protruding concrete reinforcing bar unit according to the third embodiment is manufactured.

[0055] According to the manufacturing method of embodiment 3, the control unit or the like positions and holds each of the L-shaped reinforcements 1 and the non-structural reinforcements 4 in each of the frame bodies 21 to 24, and after spot welding at one point is completed, the frame bodies are rotated horizontally in sequence to spot weld the next abutting point, and this rotation and spot welding operation is repeated until spot welding has been performed on all of the abutting points, making it possible to manufacture protruding concrete reinforcing bar units extremely efficiently and accurately.

[0056] Furthermore, in the manufacturing method or device according to the present invention, as shown in FIG. 4(b), the frames 21-23 (first frames) position and hold a plurality of L-shaped reinforcements 1 so that the tips of the vertically extending portions 1a are directed downward and the horizontally extending portions 1b extend radially at predetermined intervals from each other, and the frame 24 (second frame) positions and holds ring-shaped non-structural reinforcements that are not required as reinforcing bar units in terms of specifications, design, and structure so that they abut the horizontally extending portions 1b of the L-shaped reinforcements 1, while spot welding portions (composed of electrodes 14, 15, clamping devices 16a, 16b, etc.) are welded. The L-shaped reinforcement 1 is spot-welded by rotating the L-shaped reinforcement 1 horizontally by a predetermined angle using the rotating shaft 25 (rotating part) by means of a control unit or manually, and the laterally extending part 1b of one of the multiple L-shaped reinforcement 1 is moved to the position of the spot welding part and spot-welded (rotating operation and spot welding operation) until spot welding is performed on all of the abutting parts, so that spot welding of the abutting parts between the multiple L-shaped reinforcement 1 and the non-structural reinforcement 4 can be performed extremely efficiently and accurately.

[0057] [Embodiment 4] Next, Fig. 5(a) is a plan view illustrating a manufacturing method of a reinforcing bar unit for projection according to embodiment 4 of the present invention, and Fig. 5(b) is a side view thereof. Fig. 5 shows the case of manufacturing a reinforcing bar unit of the type (with screw) in which the tip end portion of the vertically extending part of the L-shaped bar explained in Fig. 9(b) is separated and separated as a separate body.

[0058] In Figure 5, similarly to the content described above in Figure 4, a total of eight L-shaped reinforcements 1 are first arranged upside down from the state in which they are used when constructing the protruding concrete (with the tips of each vertically extending portion 1a of the L-shaped reinforcement 1 extending downward), that is, with the female screw sockets (two-part screws) 1aa attached to the tip of each vertically extending portion 1a of each L-shaped reinforcement 1 facing downward, and then each L-shaped reinforcement 1 is positioned and held in place by frames 21, 22 for uniformly arranging each horizontally extending portion 1b relative to the L-shaped reinforcement 1 radially, and a frame 23a for arranging each vertically extending portion 1a (the tip portions of the vertically extending portions 1a (see symbols 33c, 33e in Figure 9(b)) are removed as they are separated as separate bodies) in the vertical direction. Furthermore, the frame 24 positions and holds each of the non-structural reinforcements 4 so that the ring-shaped non-structural reinforcements 4 come into contact with the upper surface (the lower surface in Figure 5(b)) of each laterally extending portion 1b of each of the L-shaped reinforcements 1 during construction. The frame bodies 21 to 24 are configured to be rotatable together horizontally by a rotation axis 25 in the center of the figure.

[0059] In this embodiment 4, as described above, the tip of each vertically extending portion 1a in each L-shaped reinforcement 1 is directed downward, and then the electrode 14 arranged on the upper side of each horizontally extending portion 1b and the electrode 15 arranged on the lower side of the portion of the non-structural reinforcement 4 that abuts each horizontally extending portion 1b are clamped from above and below by clamp devices 16a, 16b, respectively, and electricity is passed between the electrodes 14, 15 and they are pressed together to spot weld the abutting portions.Then, the rotating shaft 25 is rotated to rotate the L-shaped reinforcement 1 and the non-structural reinforcement 4 horizontally by a predetermined angle, and the abutting portions between the L-shaped reinforcement 1 and the non-structural reinforcement 4 that have not yet been spot welded are moved between the clamp devices 16a, 16b, and spot welding is performed in the same manner as in embodiment 3. These rotation and spot welding operations are then repeated in sequence by a control unit (not shown) configured by a microcomputer or the like, or manually, until the spot welding is performed on all of the contact portions between the eight L-shaped bars 1 and the non-structural bars 4, i.e., until the spot welding is performed on all of the contact portions. In this way, a protruding concrete reinforcing bar unit according to this embodiment 4 (a threaded reinforcing bar unit in which the tip end portion (see reference numerals 33c and 33e in FIG. 9(b)) of the vertically extending portion 1a of the L-shaped bar 1 is divided and separated as a separate body) is manufactured.

[0060] In this manufacturing method of the present embodiment 4, the L-shaped reinforcement 1 and the non-structural reinforcement 4 are positioned and held by the frame bodies 21 to 24, and each time spot welding of one abutting portion is completed, the frame bodies are rotated sequentially to spot weld the next abutting portion, and the rotation and spot welding operations are repeated sequentially by a control unit or the like until spot welding is performed on all of the abutting portions, thereby achieving the same effects as those of the embodiment 3.

[0061] Although the above describes each embodiment of the present invention, the present invention is not limited to the above-described first to third embodiments, and various modifications and variations are possible. For example, in the first to third embodiments, the nonstructural reinforcement bars 2, 3, and 4 are arranged on the upper surface of the laterally extending portion 1b of each L-shaped reinforcement bar 1 (the upper surface when in use during the construction of protruding concrete). However, the present invention is not limited to this arrangement, and the nonstructural reinforcement bars 2, 3, and 4 may be arranged on the lower surface of the laterally extending portion 1b of each L-shaped reinforcement bar 1 (the lower surface when in use during the construction of protruding concrete). Furthermore, in the first embodiment, two ring-shaped nonstructural reinforcement bars 2 and 3 with different radii are joined and fixed to the laterally extending portion 1b of each L-shaped reinforcement bar 1. However, in the present invention, one ring-shaped nonstructural reinforcement bar may be joined and fixed to the laterally extending portion 1b of each L-shaped reinforcement bar 1. [Explanation of symbols]

[0062] 1 L muscle 1a The vertical part of the L-shaped bar 1aa female thread socket 1b The part of the L-shaped muscle that extends horizontally 2,3,4 Ring-shaped non-structural reinforcement 11 Foundation 12 Vertical stand 13 Horizontal support stand 14,15 electrode 16a, 16b Clamping device 21,22,23,23a,24 Frame 25 Rotation axis 40 Anchor bars

Claims

1. A rebar unit for protrusions in a Shinkansen roadbed used when constructing protruding concrete in a Shinkansen roadbed, characterized in that ring-shaped non-structural reinforcement bars that are not necessary for the specifications, design, or structure of the rebar unit are spot welded to each of the horizontally extending parts of a plurality of L-shaped reinforcements, and the plurality of L-shaped reinforcements are fixed in a state where they are positioned and arranged at predetermined intervals from each other.

2. A method for manufacturing a reinforcing bar unit for a Shinkansen roadbed protrusion used when constructing a Shinkansen roadbed protrusion concrete, an arrangement step of positioning and arranging the plurality of L-shaped reinforcements using a frame body so that the horizontally extending portions of the plurality of L-shaped reinforcements extend radially at predetermined intervals from each other; abutting step of abutting ring-shaped non-structural reinforcement that is not required in terms of specifications, design, and structure as a reinforcing bar unit to each of the horizontally extending portions of the plurality of L-shaped reinforcements; A method for manufacturing a reinforcing bar unit for a protrusion in a Shinkansen roadbed, characterized by including a joining step of joining each intersection of each of the horizontally extending portions of the abutting L-shaped bars and the ring-shaped non-structural bars by spot welding.

3. a first frame that positions and holds the plurality of L-shaped reinforcements so that the tips of the longitudinally extending portions of the reinforcements are directed downward and the transversely extending portions of the reinforcements extend radially from each other at predetermined intervals; a second frame body that positions and holds ring-shaped non-structural reinforcement bars that are not required in terms of specifications, design, and structure as a reinforcing bar unit so that they abut each portion extending laterally of the L-shaped reinforcement bars; a spot welded portion that joins by spot welding the laterally extending portion of the L-shaped reinforcement held by the first frame body and the abutting portion of the ring-shaped non-structural reinforcement held by the second frame body; a rotating unit that rotates the first frame body and the second frame body by a predetermined angle, and moves the portion of the abutment between the horizontally extending portion of one of the plurality of L-shaped reinforcements and the ring-shaped non-structural reinforcement that has not yet been spot-welded to the position of the spot weld; and wherein the rotation and spot welding operations are repeated sequentially until all of the contact portions are joined by spot welding.

4. A reinforcing bar unit for protrusions in Shinkansen roadbeds as described in claim 1, characterized in that each of the horizontally extending portions of the multiple L-shaped bars has a ring-shaped non-structural bar joined by spot welding that is not necessary for the specifications, design, and structure of the reinforcing bar unit, and each of the vertically extending portions of the L-shaped bars has a ring-shaped structural bar joined by spot welding that is necessary for the specifications, design, and structure of the reinforcing bar unit.

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