Bridge girder removal device and bridge girder removal method

Abstract

To provide a bridge girder removal device and a bridge girder removal method that enable mitigation of an impact that occurs when finishing cutting a bridge girder.SOLUTION: A bridge girder removal device 1 is equipped with a straddle girder 2 that straddles a first cutting plane CS1 of a bridge girder G and has both ends fixed to the bridge girder G, and cutting means for cutting the bridge girder G along the first cutting plane CS1. Using this bridge girder removal device 1, a bridge girder removal method cuts and removes the existing bridge girder G in a direction that intersects the bridge axis direction. The bridge girder removal method comprises the steps of straddling the straddle girder 2 and cutting the bridge girder G along the first cutting plane CS1.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a bridge girder removal device and a bridge girder removal method used for replacing a bridge. [Background technology]

[0002] When replacing an aging bridge, the existing bridge girders may be removed and new bridge girders may be laid. When removing the existing bridge girders, they may be chipped using a chipping device, but chipping bridge girders requires a lot of time and effort. In some cases, the bridge girders are lifted and removed using a lifting machine, but this requires a large-scale lifting machine, and a large amount of land is required around the bridge to install such a lifting machine. Patent Document 1 discloses a method for lifting and removing an existing bridge girder that spans a bridge. In the replacement method of Patent Document 1, a jack installed below the existing bridge girder is used to jack up the girder, and then the girder is sent out in the direction of the bridge axis. In the replacement method of Patent Document 1, it is necessary to secure a site below the bridge girder to install the jack.

[0003] It is possible to omit or reduce the size of jacks and lifting machines by cutting and dividing the bridge girder. However, when cutting the bridge girder perpendicular to the bridge axis, the bridge's own weight and prestress force are concentrated in the uncut parts, so there is a risk of an impact being generated when the last remaining uncut parts are cut. One method to mitigate this type of impact is to install shoring under the existing bridge girder to support it from below. However, if there is a road or railway in use or a large river below the bridge, it is difficult to install shoring. Furthermore, if the bridge is located at a high altitude, it is necessary to install large-scale shoring, which requires a great deal of cost and effort. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-19508 A Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a bridge girder removal device and a bridge girder removal method that can mitigate the impact that occurs when cutting of a bridge girder is completed. [Means for solving the problem]

[0006] The bridge girder removal device of the present invention, which solves the above-mentioned problems, is used when cutting and removing an existing bridge girder in a direction intersecting the bridge axis direction, and is equipped with a spanning girder that is installed across the cut surface of the bridge girder and has both ends fixed to the bridge girder, and cutting means that cuts the bridge girder along the cut surface. In addition, the bridge girder removal method of the present invention involves cutting and removing an existing bridge girder in a direction intersecting the bridge axis direction, and includes the steps of installing a spanning girder across the cut surface of the bridge girder, and cutting the bridge girder along the cut surface, wherein the bridge girder is held in place by the spanning girder when it is cut along the cut surface. According to the bridge girder removal device and bridge girder removal method, the straddling girder is fixed to the bridge girder across the cutting surface, so that the straddling girder can suppress the displacement that occurs in the cut part when the bridge girder is cut. Therefore, it is possible to mitigate the impact that occurs when the bridge girder is cut. In addition, even if it is difficult to install shoring below the bridge girder, it is possible to cut and remove the bridge girder.

[0007] The bridge girder removal device may further include a plurality of temporary supports arranged at intervals in the bridge axis direction on the bridge girder, a plurality of temporary girders erected on the temporary supports, and a bridge girder suspension member suspended from the temporary girders and suspending the bridge girder near one end of the spanning girder. A bridge girder removal method using such a bridge girder removal device includes a temporary girder installation process in which a plurality of temporary supports are arranged at intervals in the bridge axis direction on the bridge girder and a plurality of temporary girders are erected on the temporary supports; a spanning girder installation process in which a spanning girder is installed so as to span the cut surface of the bridge girder; a suspension member installation process in which a bridge girder suspension member suspended from the temporary girder is fixed to the bridge girder near one end of the spanning girder; and a cutting process in which the bridge girder is cut along the cut surface, and the bridge girder when cut along the cut surface is held by the spanning girder and the bridge girder suspension member. With this bridge girder removal device and bridge girder removal method, the bridge girder is suspended by the bridge girder suspension member, which prevents the bridge girder from bending under its own weight when it is cut, and thus reduces the impact that occurs at the cut part when cutting of the bridge girder is completed.

[0008] Furthermore, if the bridge girder suspension member suspends the bridge girder via a steel rod fixed to the temporary girder and a center hole jack through which the steel rod is inserted, the impact when the bridge girder is cut can be more effectively mitigated. Furthermore, if a suspension crane capable of moving along the temporary girder is provided, the sections cut from the bridge girder can be temporarily placed. In addition, if a transport cart is provided that can move along the temporary girders and transports the sections cut from the bridge girder, the sections can be easily transported (carried out). Furthermore, if a mobile cart with a working platform that can move along the temporary girders is provided, a scaffolding can be secured via the temporary girders, eliminating the need to form a separate temporary scaffolding. Effect of the Invention

[0009] According to the bridge girder removal device and bridge girder removal method of the present invention, it is possible to mitigate the impact that occurs when cutting of the bridge girder is completed. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a side view showing a bridge girder removal situation according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a side view showing the bridge girder removal situation following FIG. 1. [Diagram 3] FIG. [Figure 4] FIG. 2 is a plan view showing the straddling girder and the bridge girder suspension device. [Diagram 5] FIG. 2 is a side view showing the straddling girder and the bridge girder suspension device. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] 1 is a flowchart showing the steps of a bridge girder removal method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] In this embodiment, a case where a bridge girder G of an existing bridge B is removed will be described. Figures 1 and 2 show the bridge girder removal state. As shown in Figure 1, the bridge girder G is removed by cutting the existing bridge girder G in a direction intersecting the bridge axis direction using a bridge girder removal device 1 and carrying out the cut divided bodies. In this embodiment, as shown in Figure 1, a case where a bridge girder G supported by four piers P1 to P4 arranged at intervals will be removed will be described. The bridge girder G is first cut at both ends (the ends on the pier P1 or pier P4 side) at a first cutting plane set in the direction perpendicular to the bridge axis, and then further cut at a second cutting plane set in the direction perpendicular to the bridge axis at a position a predetermined length away from the first cutting plane toward the center (piers P2 and P3 side) to remove the block body. At this time, the block body is cut into parts, cut out into a plurality of divided bodies, and carried out. Next, after removing the segments, the block body (multiple segments) is removed from the center of the bridge (middle part of piers P2, P3) in the same way as the tip part. Then, as shown in FIG. 2, the block bodies are gradually cut and removed from the bridge girder G from the bridge end and center part toward piers P2, P3. Here, when cutting the bridge girder G at the first cutting surface in the direction perpendicular to the bridge axis, the self-weight and prestress force are concentrated on the uncut part, so there is a risk of an impact being generated at the same time as the last remaining uncut part is cut. The bridge girder removal device 1 of this embodiment makes it possible to mitigate the impact generated when cutting of the bridge girder G is completed.

[0012] Fig. 3 shows the bridge girder removal equipment 1. As shown in Figs. 3 to 5, the bridge girder removal equipment 1 includes a straddling girder 2, a cutting device (not shown), a temporary support 3, a temporary girder 4, a bridge girder suspension member 5, a suspension crane 6, a transport cart 7, and a movable cart 8.

[0013] As shown in FIG. 5, the spanning girder 2 is used when cutting the bridge girder G at the first cutting surface CS1 (when cutting out the block body Gb1 to be removed first). The spanning girder 2 is installed so as to span the first cross section CS1 of the bridge girder G. The spanning girder 2 is fixed to the bridge girder G at three locations, namely, both ends and the middle part. That is, the spanning girder 2 is fixed so as to span the cut surfaces (the first cutting surface CS1 and the second cutting surface CS2) at both ends of the block body Gb1 when removing the first block body Gb1 from the bridge girder G. FIG. 6 shows the spanning girder 2. As shown in FIG. 6, the spanning girder 2 includes a main body 21, pedestals 22, 22, a jack 23, a steel bar pedestal 24, and a plurality of steel bar mounting portions 25, 25, ...

[0014] The main body 21 is made of H-shaped steel and, as shown in Fig. 5, is disposed along the bridge axis direction so as to straddle above the cutting surfaces (first cutting surface CS1 and second cutting surface CS2) for cutting out the block body B. A plurality of reinforcing ribs 26, 26, ... are fixed to the main body 21 in the space surrounded by the flanges and webs at positions corresponding to the pedestals 22, 22 and the jack 23.

[0015] The pedestal 22 is a support member for the main body 21, and is interposed between the main body 21 and the bridge girder G. In this embodiment, two pedestals 22, 22 are arranged on the base end side (piers P2, P3 side) of the first cross section CS1 of the main body 21. In this embodiment, the pedestals 22, 22 are arranged at a predetermined interval so as to support the base end and axial middle part of the main body 21. The second cut surface CS2 is arranged between the pedestals 22. As shown in FIG. 6, the pedestal 22 is made of an H-shaped steel having a length greater than the width of the main body 21, and both ends of the pedestal 22 protrude to the sides of the main body 21. Steel rod attachment parts 25 are fixed to the upper surfaces of both ends of the pedestal 22. In addition, reinforcing ribs 26, 26, ... are fixed to the space surrounded by the flange and web of the pedestal 22.

[0016] The jack 23 is a hydraulic jack, and is interposed between the main body 21 and the bridge girder G at the tip end (the end on the pier P1 side) of the main body 21, as shown in Fig. 5. The jack 23 is disposed at a distance from the base 22 so that a first cutting surface CS1 is disposed between the jack 23 and the base 22.

[0017] As shown in Fig. 6, the steel bar base 24 is fixed to the upper surface of the main body 21 above the jack 23 (at the tip of the main body 21). The steel bar base 24 is made of an H-shaped steel with a length greater than the width of the main body 21, and both ends of the steel bar base 24 protrude to the sides of the main body 21. Steel bar mounting parts 25 are fixed to the upper surfaces of both ends of the steel bar base 24. In addition, reinforcing ribs 26, 26, ... are fixed to the space surrounded by the flange and web of the steel bar base 24.

[0018] As shown in Fig. 5, the steel rod mounting portion 25 grips a steel rod 27 implanted in the bridge girder G. The spanning girder 2 is fixed to the bridge girder G via the steel rod 27 that penetrates the bridge girder G from top to bottom. In this embodiment, the spanning girder 2 is fixed to the bridge girder G using three steel rods 27, 27, ... in the bridge axis direction and two rows perpendicular to the bridge axis (six in total).

[0019] The cutting means cuts the bridge girder G. The cutting means is, for example, a wire saw. The bridge girder G is cut into each block body B in a direction perpendicular to the bridge axis and in the bridge axis direction, and is carried out as a plurality of divided bodies. As shown in Fig. 1, a plurality of temporary supports 3 are arranged on the bridge girder G at intervals in the bridge axis direction. The temporary supports 3 support the temporary girder 4. In this embodiment, the temporary supports 3 are arranged above the piers P1 to P4, respectively. The temporary supports 3 have the strength to support the temporary girder 4, and the structure thereof is not limited. As shown in Fig. 1, the temporary girders 4 extend in the bridge axis direction and are supported by temporary supports 3. In this embodiment, four temporary girders 4 are installed side by side at intervals in the direction perpendicular to the bridge axis as shown in Fig. 3. The temporary girders 4 movably support the bridge girder suspension members 5, suspension crane 6, transport cart 7, and movable cart 8. Note that the materials constituting the temporary girders 4 and the number and arrangement of the temporary girders 4 are not limited.

[0020] As shown in Fig. 5, the bridge girder suspension member 5 is suspended from the temporary girder 4 and suspends the bridge girder G near the base end of the straddling girder 2 (the right side panel in Fig. 5). The bridge girder suspension member 5 is suspended by a suspension member 51 extended from the temporary girder 4 and suspends the bridge girder via a steel rod 52 fixed to the temporary girder 4 and a center hole jack (not shown) through which the steel rod 52 is inserted. Fig. 7 shows the bridge girder suspension member 5. As shown in Fig. 7, the bridge girder suspension member 5 includes a pair of beam members 53, 53, steel rod mounting portions 54, 54, suspension member mounting portions 55, 55, and connecting members 56, 56.

[0021] The beam material 53 is made of H-shaped steel. Steel bar mounting parts 54 are fixed to the upper surfaces of both ends of the beam material 53. The pair of beam materials 53, 53 are arranged side by side with a gap between them and connected by a connecting member 56. A reinforcing rib 57 is fixed to the beam material 53 in a space surrounded by the web and flange at a position corresponding to the steel bar mounting part 54 and the hanging material mounting part 55. The steel rod mounting portion 54 is horizontally supported on the upper surfaces of the pair of beam materials 53, 53. The steel rod mounting portion 54 is capable of fixing the steel rods 52, 52 fixed (implanted) to the temporary girder 4.

[0022] The hanging member mounting parts 55 are capable of fixing the hanging member 51 suspended from the temporary girder 4. The hanging member mounting parts 55 are horizontally installed on the upper surfaces of the pair of beam members 53, 53 between the steel bar mounting parts 54. In this embodiment, the hanging member mounting parts 55 are disposed at two locations, one in front of the bridge girder suspension member 5 and one in front of the bridge girder suspension member 5, with an interval between them. The connecting member 56 is a steel material that connects the pair of beam materials 53, 53 together, and is disposed directly below the hanging material mounting portion 55.

[0023] As shown in Fig. 3, the suspension crane 6 is suspended from the temporary girder 4 and is movable along the temporary girder 4 (in the bridge axis direction). The suspension crane 6 suspends the sections cut from the bridge girder G. The suspension crane 6 includes a main frame 61, and a lifting equipment 62 and a temporary placement platform 63 suspended from the main frame 61. The main frame 61 is supported horizontally on multiple temporary girders 4 and is movably supported along the temporary girders 4 via multiple traveling means 64. The lifting equipment 62 is movable in a direction perpendicular to the bridge axis, and transfers the sections to a temporary placement support 63. The temporary placement support 63 is suspended from the center position of the suspension crane 6 in the direction perpendicular to the bridge axis, and allows the sections cut out from the bridge girder G to be temporarily placed thereon.

[0024] As shown in Figure 3, the transport cart 7 of this embodiment comprises a front-view gate-shaped cart body 71 horizontally mounted on two temporary girders 4, 4 arranged at the center, a storage facility 72 suspended from the cart body 71, and a number of transfer lifting facilities 73, 73, ... movably suspended from the cart body 71. The trolley body 71 is capable of moving in the bridge axial direction on the temporary girders 4. The storage facility 72 is capable of storing the divided bodies temporarily placed on the temporary receiving stand 63 of the suspension crane 6. The replacement lifting facility 73 hoists the divided bodies temporarily placed on the temporary receiving stand 63 and transfers them to the storage facility 72. With the divided bodies stored in the storage facility 72, the transport trolley 7 moves along the temporary girders 4 to transport the divided bodies cut off from the bridge girder.

[0025] The movable cart 8 has a work platform 81 on which workers can set up a work scaffold, etc. As shown in Fig. 3, the movable cart 8 is equipped with running means 82, 82 that runs on a pair of temporary girders 4, 4 arranged on the left and right, respectively, and an upper girder 83 supported by the running means 82, 82, and the work platform 81 is suspended by the upper girder 83 via a hoisting wire 84. The movable cart 8 can move along the temporary girders 4 (in the bridge axis direction) by the running means 82. In addition, the suspension crane 6, the transport cart 7 and the movable cart 8 can move individually along the temporary girder 4.

[0026] Next, a bridge girder removal method using the bridge girder removal device 1 will be described. The bridge girder G is cut in a direction intersecting the bridge axis direction (perpendicular to the bridge axis), divided, and then removed. Figure 8 shows the steps of the bridge girder removal method of this embodiment. As shown in Figure 8, the bridge girder removal method includes a temporary girder erection process S1, a straddling girder installation process S2, a suspension member installation process S3, a tension introduction process S4, a cutting process S5, and a transport process S6. In the temporary girder erection process S1, first, a plurality of temporary supports 3, 3, ... are arranged at intervals in the bridge axis direction on the bridge girder G. After the temporary supports 3 are arranged, a plurality of temporary girders 4, 4, ... are erected on the plurality of temporary supports 3, 3, ... (see FIG. 1).

[0027] In the spanning girder installation process S2, as shown in FIG. 5, the spanning girder 2 is installed so as to span the first cross section CS1 of the bridge girder G. First, holes for steel bars are drilled in the bridge girder G. The locations for drilling the holes for steel bars are surveyed and marked in advance. A support material (not shown) for preventing falling is placed on the underside of the drilled holes to prevent debris generated during drilling of the holes for steel bars from falling. In this embodiment, holes for wire saw cutting are drilled in conjunction with drilling the holes for steel bars. Next, a steel rod 27 for the spanning girder is installed in a steel rod hole formed at a position corresponding to the installation location of the spanning girder 2. The gap between the steel rod 27 and the steel rod hole is filled with a solidifying material such as grout to fix the steel rod 27. Then, the spanning girder 2 is installed using the steel rod 27. In this embodiment, the spanning girder 2 is installed on the bridge girder G using six steel rods 27, 27, ...

[0028] In the suspension member installation process S3, the bridge girder suspension member 5 is installed. As shown in Fig. 5, the bridge girder suspension member 5 is suspended from the temporary girder 4 and fixed to the bridge girder G. A steel rod 52 is installed in a steel rod hole formed in a position corresponding to the bridge girder suspension member 5, and this steel rod 52 is used to fix the bridge girder suspension member 5 to the bridge girder G. In this embodiment, two bridge girder suspension members 5, 5 are installed side by side along the bridge axis direction. In the tension introduction process S4, the necessary tension and load are introduced to the jacks of the straddling girder 2 and the bridge girder suspension member 5. During cutting, the tension must be constantly managed, so it is measured using a pressure gauge.

[0029] In the cutting process S5, the bridge girder G is cut along the cutting surface (first cutting surface CS1) in a direction intersecting the bridge axis direction. When the bridge girder G is cut along the cutting surface, it is held by the straddling girder 2 and the bridge girder suspension member 5. The straddling girder 2 supports the bridge girder G on both sides of the first cutting surface CS1. The bridge girder suspension member 5 supports the bridge girder G on the piers P2 and P3 sides of the cutting surface. When cutting the first cross section CS1, the tension by the jack is adjusted to gradually displace the tension side body so that no impact occurs. After cutting the bridge girder G at the first cross section CS1 (cutting the edge), the straddling girder 2 is removed. Next, the bridge girder G is cut at each point using a wire saw, and the divided parts are temporarily placed on the suspension crane 6.

[0030] In the transportation process S6, the divided body cut from the bridge girder G is transported by the transport cart 7 which moves along the temporary girder 4. In the transportation process S6, the divided body is transferred from the suspension crane 6 to the transport cart 7, and the transport cart 7 is moved along the temporary girder 4 to carry out the divided body.

[0031] Similarly, in the central part of the bridge, the straddling girder installation process S2, the suspension member installation process S3, the tension introduction process S4, the cutting process S5, and the transporting process S6 are performed, and the bridge girder G is cut. Next, the cantilever-shaped bridge girder G extending to the left and right from the central piers P2, P3 is gradually cut and removed from the tip side by repeating the suspension member installation process S3, the tension introduction process S4, the cutting process S5, and the transportation process S6 (see Figure 2). In the hanging member installation step S3 in the second and subsequent construction cycles, the bridge girder hanging member 5 arranged on the tip (cut surface) side is also moved to the base end side (opposite the cut surface). When three bridge girder hanging members 5 are used, tension is introduced to only the two at the tip end in the tension introduction step S4, and then the cutting step S5 is carried out. In the hanging member installation step S3 in the subsequent construction cycle, tension is introduced to the jack for the third bridge girder hanging member 5, and then the first bridge girder hanging member 5 located at the tip end side is removed and moved to the base end side of the third bridge girder hanging member 5.

[0032] According to the bridge girder removal device 1 and bridge girder removal method of the present embodiment, since the spanning girder 2 is fixed to the bridge girder G across the cutting surface, the spanning girder 2 can suppress the displacement that occurs in the cut portion when the bridge girder G is cut. Therefore, it is possible to mitigate the impact that occurs when cutting the bridge girder G is completed. Furthermore, even if it is difficult to install shoring below the bridge girder G, it is possible to cut and remove the bridge girder G. In addition, because the bridge girder G is suspended by the bridge girder suspension members 5, bending of the bridge girder G due to its own weight when the bridge girder G is cut is suppressed, and thus the impact generated at the cut portion when cutting of the bridge girder G is completed can be mitigated. Because the bridge girder suspension members 5 suspend the bridge girder G via the center hole jack, the impact when the bridge girder G is cut can be mitigated more effectively.

[0033] Since a suspension crane 6 for suspending the divided body is provided, the cut divided body can be held. In addition, since the transport cart 7 is provided, which can move along the temporary girder 4 and transports the divided bodies cut from the bridge girder G, the divided bodies can be easily transported (carried out). Furthermore, since the mobile cart 8 is equipped with a working platform 81 and can move along the temporary girders 4, a foothold can be secured via the temporary girders 4, eliminating the need to form a separate temporary scaffolding from the ground.

[0034] Although an embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and each of the above-described components can be appropriately modified without departing from the spirit of the present invention. In the above embodiment, a case has been described in which the spanning girder 2 is used when cutting the first cutting surface CS1, but the timing of using the spanning girder 2 is not limited to this, and for example, it may also be used when cutting the bridge girder G at a location other than the first cutting surface CS1. The number of bridge girder suspension members 5 used when cutting the bridge girder is not limited and may be determined appropriately. In the above embodiment, the case where the divided bodies are transported using the transport cart 7 has been described, but the method of transporting the divided bodies is not limited thereto, and for example, the divided bodies may be transported using a suspension crane 6. [Explanation of symbols]

[0035] 1. Bridge girder removal device 2. Straddle girder 3 Temporary Support 4 Temporary girder 5 Bridge girder support members 51 Hanging material 52 steel rod 6. Suspension crane 7 Transport Cart 8 Mobile trolley CS1 First cutting plane G Bridge girder P1~P4 Piers

Claims

1. A bridge girder removal device for cutting and removing an existing bridge girder in a direction intersecting the bridge axis direction, A span girder that is spanned across the cut surface of the bridge girder and has both ends fixed to the bridge girder; and cutting means for cutting the bridge girder along the cutting surface.

2. A plurality of temporary supports arranged at intervals in the bridge axis direction on the bridge girder; A plurality of temporary girders installed on the temporary supports; A bridge girder suspension member suspended from the temporary girder, 2. The bridge girder removal device according to claim 1, wherein the bridge girder suspension member suspends the bridge girder in the vicinity of one end of a straddling girder.

3. The bridge girder removal device according to claim 2, characterized in that the bridge girder suspension member suspends the bridge girder via a steel rod fixed to the temporary girder and a center hole jack through which the steel rod is inserted.

4. 3. The bridge girder removal device according to claim 2, further comprising a suspension crane that is movable along the temporary girder and suspends the section body cut from the bridge girder.

5. 3. The bridge girder removal device according to claim 2, further comprising a transport cart that is movable along the temporary girder and transports the section body cut from the bridge girder.

6. The bridge girder removal device according to claim 2, further comprising a mobile carriage capable of moving along the temporary girder and having a working platform.

7. A bridge girder removal method in which an existing bridge girder is cut and removed in a direction intersecting the bridge axis direction, A step of spanning a span girder so as to span the cut surface of the bridge girder; and cutting the bridge girder along the cutting surface. A bridge girder removal method, characterized in that the bridge girder is held by the spanning girder when the bridge girder is cut along the cutting surface.

8. A bridge girder removal method in which an existing bridge girder is cut and removed in a direction intersecting the bridge axis direction, A temporary girder erection process of disposing a plurality of temporary supports at intervals in the bridge axis direction on the bridge girder and erecting a plurality of temporary girders on the temporary supports; A span girder spanning process of spanning a span girder so as to span the cut surface of the bridge girder; A suspension member installation process for fixing a bridge girder suspension member suspended from the temporary girder to the bridge girder in the vicinity of one end of the straddling girder; A cutting process of cutting the bridge girder along the cutting surface, A bridge girder removal method, characterized in that the bridge girder is held by the spanning girder and the bridge girder suspension member when the bridge girder is cut along the cutting surface.

9. 9. The bridge girder removal method according to claim 8, further comprising a transport step of transporting a section cut from the bridge girder by a transport cart that moves along the temporary girder.

10. In the cutting step, the divided body is supported by a suspension crane supported by the temporary girder, 10. The bridge girder removal method according to claim 9, wherein in the transporting step, the divided body is transferred from the suspension crane to the transport cart.

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