Suspension jig and method for removing guardrails using the same

Abstract

To provide a suspension jig that has high construction efficiency, can reduce the burden on workers, and also leads to cost reduction. 【Solution means】On the upper surface of the side part located beside the removal target part among the guardrails, a pair of transfer parts placed with the longitudinal direction orthogonal to the guardrails, An outer side fixing part that is vertically provided on the outer side of each of the transfer parts and is arranged along the outer surface of the guardrail, A presser plate that is detachably vertically provided on the track side of each of the transfer parts and presses the guardrail, and a track side fixing part of an H-shaped steel that sandwiches the guardrail between the outer side fixing part and the presser plate, A pair of support parts erected on the upper surface of each of the transfer parts, An H-shaped steel girder part that has a longitudinal direction parallel to the guardrail and has its left and right ends placed on the upper ends of the respective support parts and is detachably connected and spanned above the removal target part, An H-shaped steel beam part that is detachably connected to the lower part of the flange of the girder part with the longitudinal direction orthogonal to the guardrail, A suspension part supported by the beam part, and the suspension jig has these components.

Description

Technical Field

[0001] The present invention relates to a hanging jig useful when removing a portion of a concrete railing of an elevated railway bridge on which a bullet train runs, which is close to an electrification pole (a concrete pole for an electric railway line), and a method for removing the railing using the same.

Background Art

[0002] An elevated railway bridge on which a bullet train runs has a concrete floor slab on which a slab mat for laying a railway line is placed and supported by piers, and the side portions of the concrete floor slab project outward, and the side edges have erected concrete railings. FIG. 1 is an image diagram of railing work at a location where there is a sidewalk below. When performing work on the railing, at a location where there is a sidewalk below, generally, as shown in FIG. 1, a scaffold is raised upward from a crane truck to perform the work. In FIG. 1, the cross on the right side is a symbol meaning a railway line.

[0003] In an elevated railway bridge on which a bullet train runs, electrification poles are provided at regular intervals inside the railing. FIG. 2 is an image diagram showing the positional relationship among the electrification pole, the railing, and the sidewalk. When renovating the electrification pole for seismic reinforcement, it is necessary to remove a portion of the concrete railing that is close to the old electrification pole.

[0004] At locations where there are sidewalks, as shown in Fig. 1, the crane of the crane truck parked on the lower sidewalk can be used to carry the removed concrete blocks onto the loading platform. However, at locations where there are no sidewalks, since cranes cannot be used, conventionally, for the entire part of the railing that needs to be removed, a core drilling operation is carried out at dozens of locations by workers using a concrete drilling machine to drill cores with a diameter of 20 cm. Further, the workers carry concrete blocks weighing about 10 - 20 kg and transport them through the passage groove beside the slab mat for a distance of about 100 - 500 m to the exit door that does not obstruct the running of the Shinkansen in a human wave tactic like a bucket relay, and then carry them out to remove the existing railing. However, the number of holes that one worker can drill is at most about 9 - 12 holes per day. Moreover, work could only be carried out at night when the train was not running. It takes about three days to replace one electrified pole, but the number of days required to remove the obstructed part of the railing is much more than that of the electrified pole replacement pace, which has been the cause of the long-term renovation work.

[0005] For the purpose of use in places where it is not possible to secure a space for raising and lowering sound insulation plates outside the track using an aerial work vehicle or a crane truck from the sidewalk outside the track, a device for replacing the sound insulation plates constituting the sound insulation wall in the elevated railway track using a rotating column is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, the concrete railing that forms the railing of the elevated railway bridge on which the Shinkansen runs is not stacked in multiple stages in the vertical direction. Instead, it is further connected to the left and right walls to form an integrated unit. There is no working space outside the railing, and there are electrification poles inside the railing. Therefore, the above-described replacement device cannot be used. Furthermore, in the case of an elevated railway bridge on which the Shinkansen runs, it is necessary to perform the drilling work and the transportation work to the exit door only at night, which causes problems such as a long construction period and high construction costs.

[0008] The present invention has been made in view of such problems, and an object thereof is to provide a hanging jig that has good construction efficiency, can reduce the burden on workers, and leads to cost reduction, and a method for removing a railing using the same.

Means for Solving the Problems

[0009] In a first aspect of the present invention, among the concrete railings provided on an elevated railway bridge on which a Shinkansen runs, a portion where an electrification pole is close to the track side is defined as a removal target portion. On the upper surface of the side portion located beside the removal target portion of the railing, a pair of transfer portions placed with the longitudinal direction orthogonal to the railing are provided. External side fixing portions that are vertically provided on the outer side of each of the transfer portions and are arranged along the outer surface of the railing are provided. Pressing plates that are detachably vertically provided on the track side of each of the transfer portions and press the railing are provided, and a track side fixing portion of H-shaped steel that sandwiches the railing between the external side fixing portion and the pressing plate is provided. A pair of support columns standing on the upper surface of each of the transfer portions are provided. An H-shaped steel girder portion that is removably connected with its left and right ends placed on the upper ends of the respective support columns with the longitudinal direction parallel to the railing and spans over the removal target portion is provided. An H-shaped steel beam portion that is removably connected to the lower part of the flange of the girder portion with the longitudinal direction orthogonal to the railing is provided. A hanging portion supported by the beam portion is provided, and a hanging jig is provided.

[0010] According to the first aspect of the present invention, the construction efficiency is good, the burden on workers can be reduced, and it leads to cost reduction.

[0011] Further, it is preferable that the hanging portion includes a plain trolley supported so as to be able to travel on the lower flange while sandwiching the web of the beam portion, a hoist having hooks at the upper and lower portions and connected to the lower portion of the plain trolley, and a multi-eye bolt that can be connected to the lower portion of the hoist and is attached to the upper surface of the guardrail. The removed portion that has been cut out can be easily carried out.

[0012] Further, the transfer portion, the outer side fixing portion, and the support column portion are made of H-shaped steel. The upper end portion of the outer side fixing portion is fixed to the lower surface of the end portion of the lower flange on the outer side of the transfer portion. The upper end portion of the track side fixing portion is bolted to the lower surface of the end portion of the lower flange on the track side of the transfer portion. The pressing plate is bolted to the flange on the guardrail side of the track side fixing portion so that the distance from the flange to the pressing plate can be adjusted. The tip of the beam portion on the track side is provided at a position where it does not contact the electrified pole. It is preferable that the beam portion is provided with a stopper at the outer side tip. Further, the working efficiency is improved.

[0013] Further, a second aspect of the present invention provides a method for removing a guardrail, which includes steps of installing the hanging jig on the guardrail, drilling through holes at the left and right ends of the removed portion, circulating and running a wire saw through the through holes to cut out the removed portion, lifting the removed portion with the hanging portion, moving the removed portion to the tip side of the beam portion with the hanging portion, and lowering the removed portion to the outside of the guardrail.

[0014] According to the second aspect of the present invention, the construction efficiency is good, the burden on workers can be reduced, and it leads to cost reduction.

[0015] Furthermore, the step of installing the hanging jig on the guardrail is Connecting the external side fixing part and the track side fixing part to the transfer part, placing them on the side part, adjusting the bolts of the pressing plate, and clamping the guardrail; Erecting the support part on the transfer part, movably suspending the hanging part on the beam part, attaching the beam part to the lower surface of the girder part, and supporting and connecting both ends of the girder part with the support part; Connecting the hanging part to the upper part of the part to be removed; It is preferable to include the above steps. This facilitates on-site assembly and improves work efficiency.

Advantages of the Invention

[0016] According to the present invention, the construction efficiency is good, the burden on workers can be reduced, and it also leads to cost reduction.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Best Mode for Carrying Out the Invention

[0018] Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the present invention will be specifically described using examples with respect to the hanging jig of the present invention and the method for removing a guardrail using the same, but the present invention is not limited thereto.

Example

[0019] FIG. 3 is an explanatory view showing the positional relationship between the guardrail with the hanging jig of Example 1 of the present invention attached and the electric pole scheduled for renovation. The hanging jig 1 of this embodiment is a concrete guardrail 9 erected on the side edge of a concrete floor slab that is placed on a slab mat for laying tracks and supported by piers and projects outward in an elevated railway bridge where the Shinkansen runs. Among them, in a place where there is no sidewalk below, it is a jig suitable for removing only the part close to the old electric pole D to be renovated for seismic reinforcement during a short period of night work when no train is running.

[0020] {Configuration} FIG. 4 is a front view of the state where the removal target part of the guardrail is lifted by the hanging jig of Example 1 of the present invention. In FIG. 4, the outside of the guardrail 9 is the back side, and the inside of the guardrail 9, that is, the side where the track is laid, is the front side. Further, FIG. 5 is a schematic plan view of the state where the removal target part of the guardrail is lifted by the hanging jig of Example 1 of the present invention. In FIG. 5, the lower side of the drawing paper is the track side. In FIG. 5, the part remaining at the lower part of the lifted removal target part among the parts to be removed is not shown.

[0021] The suspension jig 1 of this embodiment is configured such that, among the concrete parapets 9 provided on an elevated railway bridge on which a bullet train runs, a portion 92 to be removed is defined as a part where the electrification pole D is close to the track side. The parapet 9 is formed by a wall body continuous with the side edge of the elevated railway bridge. The parapet 9 has a removed portion 92 and side portions (91a, 91b) located on the left and right sides of the removed portion 92, respectively. In this embodiment, the parapet 9 is flat, and the side portions 91a, the removed portion 92, and the side portion 91b are made of a single continuous piece of concrete. The side portions correspond to the left and right sides of the removed portion, in other words, the sleeve portions. The parapet 9 may be provided with joints at regular intervals.

[0022] The suspension jig 1 of the embodiment has a pair of bridging portions (2a, 2b), outer side fixing portions (32a, 32b), track side fixing portions (31a, 31b), support columns (4a, 4b), one girder portion 5, one beam portion 6, and one suspension portion 7. The suspension jig 1 of the embodiment removes a part of the parapet between a pair of bridging portions (2a, 2b) attached to the parapet 9. In this embodiment, the parapet at the location to be removed is divided into upper and lower parts and removed in two steps. In the present application, the pair of bridging portions specifically refers to a set of bridging portions in which one bridging portion of the same shape is arranged at each of the left and right positions sandwiching the removed portion. The same applies to the support columns, outer side fixing portions, and track side fixing portions described later. In FIG. 4, the dotted line portion of the parapet 9 is the lower part that is the removed portion to be removed in the second step. Since the removal of the lower part is the same as the removal of the upper part, the upper part to be removed will be described as the removed portion 92. The bridging portions (2a, 2b) are a pair of H-shaped steels placed on the upper surfaces of the side portions (91a, 91b) located on the sides of the removed portion 92 of the parapet 9 with the longitudinal direction perpendicular to the parapet 9. The bridging portions (2a, 2b) are respectively connected to the outer side fixing portions (32a, 32b) and track side fixing portions (31a, 31b) at the lower part and the support columns (4a, 4b) at the upper part. For example, the lower part of the bridging portion 2a is connected to the outer side fixing portion 32a, the track side fixing portion 31a, and the support column 4a at the upper part. The bridging portions (2a, 2b) place the lower surfaces of the lower flanges (212a, 212b) on the upper surfaces of the side portions (91a, 91b). End plates 413 are welded and integrated to the upper and lower ends of the support columns (4a, 4b).

[0023] The outer side fixing parts (32a, 32b) are vertically provided on the outer side of the transfer parts (2a, 2b), and are a pair of H-shaped steels arranged along the outer surface of the guardrail 9. The outer side fixing parts (32a, 32b) are respectively connected to the lower side of one end of the flanges (212a, 212b) of the transfer parts (2a, 2b). In this embodiment, the upper ends of the outer side fixing parts (32a, 32b) are fixed to the lower surface of the end of the lower flanges (212a, 212b) on the outer side of the transfer parts (2a, 2b). The outer side fixing parts (32a, 32b) connected to the lower part of the tip of the transfer parts (2a, 2b) are vertically provided along the outer surface of the side parts (91a, 91b), that is, the wall surface, and the surface of the flanges (322a, 322b) on the wall surface side is installed in close contact with the wall surface.

[0024] The webs (321a, 321b) of the outer side fixing parts (32a, 32b) and the webs (211a, 211b) of the transfer parts (2a, 2b) are both in a direction perpendicular to both the upper surface and the outer surface of the guardrail 9. The longitudinal direction of the webs (321a, 321b) of the outer side fixing parts (32a, 32b) is parallel to the vertical direction of the guardrail 9. Also, in this embodiment, the upper ends of the outer side fixing parts (32a, 32b) are fixed to the lower surface of the end of the lower flanges (212a, 212b) of the transfer parts (2a, 2b) by welding, and they form a member united in an L shape.

[0025] The track-side fixing parts (31a, 31b) are respectively arranged such that, with the guardrail 9 in between, the longitudinal direction is in the vertical direction parallel to the wall body of the guardrail 9 on the side opposite to the outer-side fixing parts (32a, 32b). The track-side fixing parts (31a, 31b) are detachably vertically provided on the track side of the transfer parts (2a, 2b). The track-side fixing parts (31a, 31b) are H-shaped steel members that include pressing plates (313a, 313b) for pressing the guardrail 9, and sandwich the guardrail 9 between the outer-side fixing parts (32a, 32b) and the pressing plates (313a, 313b). The track-side fixing parts (31a, 31b) are connected below the other end sides of the flanges (212a, 212b) of the transfer parts (2a, 2b) and sandwich the side parts (91a, 91b) together with the outer-side fixing parts (32a, 32b). The upper end parts of the track-side fixing parts (31a, 31b) are bolted to the lower surface of the end parts of the lower flanges (212a, 212b) on the track side of the transfer parts (2a, 2b), that is, the track-side fixing parts (31a, 31b) and the transfer parts (2a, 2b) are connected by bolts 8 and are made detachable.

[0026] The pressing plates 313 are connected to the guardrail-side flanges (312a, 312b) of the track-side fixing parts (32a, 32b) by bolts 8 so that the distance from the flanges (312a, 312b) to the pressing plates 313 can be adjusted. The pressing plates 313 press the side parts (91a, 91b) of the guardrail 9 by tightening the flanges (312a, 312b) with bolts 8. The track-side fixing parts (31a, 31b) and the transfer parts (2a, 2b) are connected by bolts 8. On the side opposite to sandwiching the outer-side fixing parts (32a, 32b) and the guardrail 9, the track-side fixing parts (31a, 31b) are adjusted by tightening the bolts 8 with a ratchet so that a plurality of pressing plates 313 connected to the wall surface side surfaces of the flanges (312a, 312b) by bolts 8 are in close contact with the surface on the track side of the side parts (91a, 91b), and are installed with the longitudinal direction parallel to the height direction of the wall surface. The dotted line part in Fig. 4 shows the part of the pressing plate 313 hidden by the flanges (312a, 312b) when viewed from the track side (front side).

[0027] The support parts (4a, 4b) are a pair of H-shaped steels erected on the upper surfaces of the transfer parts (2a, 2b) respectively, and are provided with end plates 413 at both the upper and lower ends. The support parts (4a, 4b) and the transfer parts (2a, 2b) are connected by bolts 8. More specifically, the support parts (4a, 4b) are erected on the upper surfaces of the upper flanges (212a, 212b) of the transfer parts (2a, 2b), and are bolted and connected to the upper surfaces of the upper flanges (212a, 212b) of the transfer parts (2a, 2b) and the end plates 413 on the lower end sides of the support parts (4a, 4b). Instead of using the end plates, right-angle brackets may be used.

[0028] The cross member 5 is an H-shaped steel with its longitudinal direction parallel to the railing 9, and its left and right ends are placed on the upper ends of the support parts (4a, 4b) respectively for detachable connection and spanned above the removal target part 92. Both ends of the flange 512 are placed on the support parts (4a, 4b) and connected in a gate-like shape. More specifically, one end of the cross member 5 is placed on the support part 4a and the other end is placed on the support part 4b, and both support parts are used as legs and placed so as to span upward for connection. The lower surfaces of the lower flanges (512a, 512b) of the cross member 5 and the end plates 413 on the upper end sides of the support parts (4a, 4b) are bolted and connected. Instead of using the end plates, right-angle brackets may be used.

[0029] The beam part 6 is an H-shaped steel detachably connected to the lower part of the flanges (512a, 512b) of the cross member 5 with its longitudinal direction perpendicular to the railing 9. The tip on the track side of the beam part 6 is provided at a position where it does not hit the electrified pole D. The beam part 6 is provided with a stopper at the outer tip. The beam part 6 is shorter on the track side than the cross member 5 and longer on the outer side. That is, the beam part 6 extends cantilever-like to the outer side without hitting the electrified pole D and is connected to the cross member 5. The beam part 6 bolts and connects the upper flange 612 of the beam part 6 perpendicular to the cross member 5 to the central lower surface of the lower flanges (512a, 512b) of the cross member 5. The beam part 6 is fixedly connected to the cross member 5 and does not move in either the direction perpendicular to the railing 9 or the parallel direction. The beam part 6, that is, the beam, may be an I-beam of I-shaped steel or an H-beam of H-shaped steel.

[0030] The suspension part 7 is supported by the beam part 6. The suspension part 7 includes a plain trolley 71 that is supported so as to be able to run on the lower flange 612 with the web 611 of the beam part 6 interposed therebetween, a hoist 73 that has hooks (72a, 72b) at the upper and lower parts and is connected to the lower part of the plain trolley 71, and a multi-eye bolt 74 that can be connected to the lower part of the hoist 73 and is attached to the upper surface of the railing 9. Since stoppers are provided at the outer ends of the beam part 6, there is no risk of the plain trolley 71 running on the lower flange 612 as a rail from falling. The suspension part 7 is supported by the beam part 6.

[0031] The suspension jig 1 of this embodiment can be inserted from the side of each member's electrification pole even in a situation where the electrification pole is inside the railing and it is impossible to work outside the railing, and it is configured to enable on-site assembly, installation, and disassembly.

[0032] {Removal method} The suspension jig 1 of this embodiment is used as follows to remove the portion of the railing 9 located behind (outside) the electrification pole, that is, the portion where there is an obstacle to the replacement of the electrification pole (obstacle portion).

[0033] The method for removing the railing of this embodiment uses the suspension jig 1 of this embodiment. This method includes the steps of installing the suspension jig 1 on the railing 9, drilling through holes 94 at the left and right lower ends of the removal target portion 92, circulating a wire saw through the through holes 94 to cut out the removal target portion 92, lifting the removal target portion 92 with the suspension part 7, moving the removal target portion 92 to the tip side of the beam part 6 with the suspension part 7, and lowering the removal target portion 92 to the outside of the railing 9. The lifted removal target portion 92 is moved about 25 cm outside the railing 9, lowered onto the floor slab or gravel outside the railing with the hoist 73, the multi-eye bolt 74 is removed, and it is temporarily placed. The hoist 73 can be lowered up to 15 m below. According to this embodiment, since it can be directly carried out of the line, it is not necessary to carry out small transportation of a block drilled out into dozens by core removal to the exit door. Since the concrete block of the removal target portion 92 temporarily stored is lowered to the ground below the outside of the railing, the transportation work can be carried out using a crawler without disturbing the operation even during the day when the Shinkansen is in operation.

[0034] The step of installing the hanging jig 1 on the railing 9 is to connect the outer side fixing parts (32a, 32b) and the track side fixing parts (31a, 31b) to the transfer parts (2a, 2b) and place them on the side parts (91a, 91b) as downward U-shaped members. That is, place the member formed by assembling the transfer part (2a), the outer side fixing part (32a), and the track side fixing part (31a) as an integral unit on the side part (91a), and place the member formed by assembling the transfer part (2b), the outer side fixing part (32b), and the track side fixing part (31b) as an integral unit on the side part (91b). Further, adjust the bolts 8 of the pressing plates (313a, 313b) of the track side fixing parts (31a, 31b) respectively to clamp the railing 9, and stand the support parts (4a, 4b) on the transfer parts (2a, 2b), suspend the hanging part 7 movably in the rail on the beam part 6, attach the beam part 6 to the lower surface of the girder part 5, and support and connect both ends of the girder part 5 with the support parts (4a, 4b). It also includes the step of connecting the hanging part 7 to the upper part of the removal target part 92. The stopper at the tip of the beam part 6 can prevent the hanging part 7 from falling outside the railing even if the beam part 6 tilts during installation. It is also possible to connect the girder part 5 to the support parts (4a, 4b) and then attach the beam part 6 to the lower surface of the girder part 5. Also, it is possible to suspend the hanging part 7 on the beam part 6 after attaching the beam part 6 to the girder part 5. After connecting the outer side fixing parts (32a, 32b) to the transfer parts (2a, 2b) to form an inverted L-shaped integrated member and placing it on the side parts (91a, 91b), it is also possible to connect the track side fixing parts (31a, 31b) to the transfer parts (2a, 2b).

[0035] FIG. 6 is an explanatory view of the method for removing the guardrail according to the first embodiment of the present invention. FIG. 6 shows a state in which the multi-eye bolt 74 of the suspension part 7 is attached to the upper surface of the guardrail 9 and connected to the lower part of the hoist 73 of the suspension part 7. In FIG. 6, after the suspension jig of the first embodiment of the present invention is attached to the guardrail 9, it is before separating the upper removal target part 92 and the lower part 93. In FIG. 6, an example of a guideline of a portion that becomes a boundary line for separating the upper and lower parts is represented by a dotted line. The above-described FIG. 3 is a view of the state before separation as seen from above, and the suspension part 7 is hidden under the girder part 5. After removing the upper removal target part 92 from the lower part, a multi-eye bolt is attached to the upper part as a new removal target part and cut out, and removed in the same manner as the upper part. In FIG. 6, illustration is omitted for parts other than the girder part 5, the beam part 6 connected under the girder part 5, the suspension part 7 attached to the beam part 6, and the guardrail 9 including the portion that will later become the removal target part 92 and is connected to the suspension part 7. In FIG. 6, the hatched portion shows a cross section of the portion connected to the suspension part 7. It is before separating the removal target part 92 from the guardrail 9, and the root part is integrated with the floor slab.

[0036] In this embodiment, through holes 94 are drilled at the left and right lower ends of the removal target portion 92 using a concrete drilling machine. The height of the guardrail 9 is about 2 m. In this embodiment shown in FIG. 4, the through holes 94 are opened at a medium height. In this embodiment, the thickness of the guardrail 9 is 16 cm, but this is an example, and removal is possible even if the thickness is about 16 to 21 cm. To ensure the building limit, which is the limiting dimension when installing the guardrail of the viaduct, for the safe operation of the Shinkansen, and to provide an additional allowance (margin) considering the error due to drying shrinkage during guardrail installation, on the other hand, the guardrail cannot protrude from the boundary line of the site, and the center position cannot be shifted either, so the thickness of the guardrail is not uniform and there are some differences. However, according to this embodiment, even at locations with different thicknesses, since adjustment is made by tightening the bolts of the pressing plates 313 on the left and right respectively, there is no loosening or rattling even if the thicknesses of the left and right guardrails are different, and troubles such as the suspension part tilting or not being able to be installed stably can be prevented, and the stability is excellent. Depending on the performance of the suspension part 7, when the guardrail 9 is thick, as in this embodiment, it is preferable to drill through holes 94 at the left and right ends at the heights of the middle part and the root part of the removal target portion 92 and divide them into two vertically. Depending on the load-bearing capacity of the hoist 73 and other circumstances, the removal target portion 92 may not be divided into two but may be made into one piece.

[0037] The size of the through hole 94 is, for example, a diameter of 20 cm. By passing a wire saw through the two through holes in the vertical direction and in the direction connecting the through holes to each other, the guardrail 9 is divided into a side part 91a, a removal target part 92, a lower part 93, and a side part 91b. Even when adding up the time to form one through hole, the time to divide with a wire saw, and the time from lifting the removal target portion 92 by the suspension part 7 until the removal is completed, compared to the working time required in the past to carry dozens of blocks drilled out by core drilling to the exit door by small transportation, the removal working days can be shortened, and the removal of one removal target portion 92 is completed in about 3 days. Therefore, the number of days required for removing the obstacle part of the guardrail does not exceed the number of days required for replacing the electrification pole. While replacing the electrification pole at the location where the removal of the obstacle part has been completed, the removal of the obstacle part of the guardrail at the location where the next electrification pole replacement is scheduled can be carried out. Thus, the total construction days of the electrification pole renovation work can be significantly shortened.

[0038] FIG. 7 is a sectional view taken along line A-A of the lifting jig of Example 1 of the present invention with a part of the guardrail lifted. FIG. 8 is a sectional view taken along line B-B of the lifting jig of Example 1 of the present invention with a part of the guardrail lifted. In FIGS. 7 and 8, the lifted removal target part 92 is shown in a state of being moved in the carrying-out direction. In FIGS. 7 and 8, the hatched portions indicate cross-sections.

[0039] In this embodiment, a mini hoist is used for the hoist 73. The load capacity of the hoist 73 is 500 kg. One removal target part 92 has a width of 80 cm, a height of 1 m (divided into two parts with a total height of 2 m), and a specific gravity of 2.35. Therefore, even if the thickness is 21 cm, the weight is 394.8 kg, which is less than the load capacity. In this embodiment, the longitudinal length of the transfer part 2 and the support part 4 is 45 cm, the longitudinal length of the track side fixing part 31 and the outer side fixing part 32 is 100 cm, the longitudinal length of the girder part 5 is 130 cm, the longitudinal length of the beam part 6 is 50 cm. For any of the H-shaped steels, the web height is 10 cm. The pressing plate 313 is 10 cm square and the thickness is 9 mm, but it is not limited thereto.

[0040] Note that in this embodiment, all the frameworks are made of H-shaped steel, but the beam part may be made of I-shaped steel according to the type of the plain trolley. Also, because of the weight, the workability during assembly and disassembly is poor, but the support part may be a square pillar.

[0041] FIG. 9 is an explanatory diagram showing the positional relationship between a guardrail of another shape with the lifting jig of Example 1 of the present invention attached and the electrification pole to be renovated. Since the lifting jig 1 of this embodiment can freely adjust the space between the support parts during assembly, as shown in FIG. 9, even when the shape of the guardrail has irregularities, as long as the two locations where the support parts are provided are not stepped, it can be adjusted and attached whether the space between the support parts is narrow or wide. Even for a guardrail with the electrification pole part bulging outward, it is possible to easily remove only the obstacle part.

[0042] {Effect} According to the lifting jig and the guardrail removal method of this embodiment, the construction efficiency is good, the burden on the workers can be reduced, and the cost can be reduced.

[0043] According to this embodiment, for the part of the retaining wall where there is an obstacle to the replacement of the electrified pole, compared with cutting it out as small concrete blocks and having workers carry it out by hand many times, the carrying-out speed is significantly increased, resulting in improved construction efficiency, and the burden can be reduced because the heavy labor work is reduced. Also, the hanging jig of this embodiment has good construction efficiency in terms of easy attachment to the retaining wall and easy disassembly. Moreover, since the removal target part can be cut out large, the range that can be carried out at one time is large, and since it is easy to remove the multi-eye bolts from the removal target part after it is attached to the ground, the working time is reduced and the construction efficiency is improved.

[0044] According to this embodiment, for the removal of one removal target part of the retaining wall, the core drilling work requires 4 locations if divided and 2 locations if not divided, so it is easily possible to drill holes within one night and carry and move it from the passage groove beside the slab mat to the exit door. The retaining wall carried outwards with the hanging jig of the present invention can be lowered to the ground below even in a place without a sidewalk, and can be carried out by a heavy machine during the day even during the operation of the Shinkansen, so there is no need to transport dozens of concrete blocks to one location during night work. Since the labor cost per worker is different between day and night, the total labor cost of the electrified pole renovation work can be reduced. From the assembly and installation of the hanging jig, the cutting out of the removal target part from the retaining wall, the hanging down of the removal target part, to the carrying out of the 2 - 4 concrete blocks after core drilling, it is completed in a shorter number of days than before. Therefore, the problem that the number of days required for the removal of the retaining wall is much more than the number of days required for the replacement of one electrified pole is solved, and a significant shortening of the construction days of the electrified pole renovation work can be achieved. Furthermore, the total number of workers can be reduced compared to before, and the burden on each worker can also be reduced.

[0045] According to this embodiment, even if there is an old electrified pole inside the guardrail (rail side) without demolishing the entire guardrail made of concrete, only the removal target part, which is the part of the guardrail that hinders the renovation of the electrified pole, can be carried out of the guardrail, and moreover, it can be removed with limited working hours and few workers. Furthermore, the lifting jig of this embodiment has a simple structure and can be easily assembled and disassembled when installed on the removal target part to be demolished, so the working hours can be shortened. In addition, since the framework is composed only of H-shaped steel, it is light and strong. Also, since the plain trolley moves only from the inside (rail side) to the outside of the guardrail, that is, only in the front-rear direction, the work can be simplified and lifting and lowering are also easy.

[0046] Furthermore, according to this embodiment, no support base from the ground is required, and since it has a structure without a protruding part that hits the electrified pole inside the guardrail (rail side), it is suitable for removing the guardrail near the installation of the electrified pole on the side of the track. Also, in this embodiment, the external side fixing part and the passing part are pre-connected, and since the pressing plate is provided only on the track side fixing part, the guardrail can be clamped by placing the passing part on the side part and performing the work only on the track side. As a result, it is not necessary to work outside the guardrail when installing the lifting jig of this embodiment. Therefore, it is also excellent in safety and enables the removal work of the guardrail in places without a sidewalk.

[0047] Also, even where a crane can be used, there is no risk of the crane or the suspended object hitting the electrified pole or the electric wire, so it is excellent in convenience. Also, when it is desired to remove only the guardrail in a narrow part of about 80 cm, a large-scale device is not required, and since it can be easily attached and detached and reused at another location, a significant reduction in cost and working hours can be achieved.

[0048] Note that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention. Also, the constituent elements of the above-described embodiments can be arbitrarily combined without departing from the spirit of the invention.

Explanation of Signs

[0049] 1 Lifting jig 2 Transfer part 211 Web 212 Flange 31 Rail-side fixing part 311 Web 312 Flange 313 Pressing plate 32 Outer-side fixing part 321 Web 322 Flange 4 Support part 411 Web 412 Flange 413 End plate 5 Digit part 511 Web 512 Flange 6 Beam part 611 Web 612 Flange 7 Hanging part 71 Plain trolley 72 Hook 73 Hoist 74 Multi-eye bolt 8 Bolt 9 Fence 91 Side part 92 Part to be removed 93 Lower part 94 Through hole 95 Cutting part D Electric pole

Claims

1. The concrete railings on the elevated railway bridges on which the Shinkansen runs are to be removed from the area close to the electrification poles on the track side. A pair of bridge parts are placed on the upper surface of the side parts of the balustrade located on the sides of the removal target part with the longitudinal direction perpendicular to the balustrade; An outer fixing portion is provided on the outer side of each of the bridge portions and is disposed along the outer surface of the balustrade; a track-side fixing portion of an H-shaped steel that is detachably installed on the track side of each of the bridge sections and has a pressing plate that supports the railing, and that clamps the railing between the outer fixing portion and the pressing plate; A pair of support columns erected on the upper surfaces of the bridge portions; A girder portion of an H-shaped steel that is detachably connected to the upper end of each of the support columns with its longitudinal direction parallel to the railing and that is spanned above the portion to be removed; A beam portion of an H-shaped steel detachably connected to a lower part of the flange of the girder portion with a longitudinal direction perpendicular to the handrail; A hanging jig comprising: a hanging portion supported by the beam portion.

2. The suspension jig described in claim 1, characterized in that the suspension part comprises a plain trolley supported so as to be able to run on the lower flange by clamping the web of the beam part, a hoist having hooks on the upper and lower parts and connected to the lower part of the plain trolley, and a multi-eye bolt connectable to the lower part of the hoist and attached to the upper surface of the balustrade.

3. The bridge portion, the outer fixing portion, and the support portion are H-shaped steel, an upper end portion of the outer fixing portion is fixed to a lower surface of an end portion of a lower flange on the outer side of the connecting portion, an upper end portion of the track-side fixing portion is fastened to a lower surface of an end portion of a lower flange of the transfer portion on the track side with a bolt; The pressure plate is connected to a flange on the railing side of the track side fixing part by a bolt so that the distance from the flange to the pressure plate can be adjusted, The track-side end of the beam portion is provided at a position where it does not abut against the electrification pole, 2. The hanging jig according to claim 1, wherein the beam portion is provided with a stopper at an outer tip thereof.

4. A method for removing a railing using the hanging jig according to any one of claims 1 to 3, A method for removing a balustrade, comprising the steps of: installing the hanging jig on the balustrade; drilling through holes on the left and right ends of the part to be removed; passing a wire saw through the through holes and running it in a circular motion to cut out the part to be removed; lifting the part to be removed with the hanging part; moving it toward the tip side of the beam part with the hanging part; and lowering the part to be removed to the outside of the balustrade.

5. The step of installing the hanging jig on the railing, a step of connecting the outer side fixing part and the track side fixing part to the connecting part, placing the connecting part on the side part, and adjusting the bolts of the pressing plate to clamp the balustrade; a step of erecting the support column on the bridge section, movably hanging the hanging section from the beam section, attaching the beam section to a lower surface of the girder section, and connecting both ends of the girder section by supporting them with the support column; Connecting the hanging part to an upper part of the removal target part; 5. The method for removing a balustrade according to claim 4, further comprising:

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