JP7172916B2 - Bridge superstructure removal method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a bridge superstructure removal method, and more particularly, to a bridge superstructure removal method capable of greatly relaxing restrictions on the use of space under girder when removing a bridge superstructure. Here, in the present application, the superstructure means the superstructure of the bridge including at least the main girder, out of the main girder and floor slab of the bridge.

When removing a superstructure of a bridge, a construction method of using the space below the superstructure of the bridge to be removed is generally used.

For example, in the method of removing a bridge described in Patent Literature 1, two pairs of vents are used to repeatedly support and lower each of the bents, thereby lowering and removing the superstructure of the bridge to be removed.

However, in the above-described method of removing a bridge superstructure using a vent, the work of erecting the vent and the work of removing the superstructure using the vent do not require the use of a large crane. During this period, roads and railroads running under the girder must be closed to traffic for a relatively long period of time. In other words, the use of the space below the superstructure to be removed is greatly restricted.

JP 2006-144282 A

SUMMARY OF THE INVENTION It is an object of the present invention to provide a bridge superstructure removal method that can greatly relax restrictions on the use of the space under the girder when removing the superstructure of a bridge. do.

The present invention solves the above problems by the bridge superstructure removal method described below.

That is, a bridge superstructure removal method according to the present invention is a bridge superstructure removal method for removing a superstructure of a bridge, wherein the superstructure of the span to be removed and the span adjacent to the target span to be removed is reinforced. A reinforcing member installation step of installing a reinforcing member to extend in the direction of the bridge axis of the bridge, a crane installation step of installing a crane above the superstructure, and after the reinforcing member installation step, the span to be removed and a removal step of removing the predetermined portion of the superstructure separated by the cutting step with the crane. is.

The crane installation step may be performed after the reinforcing member installation step.

In the reinforcing member installation step, the reinforcing member may be installed in a direction extending in the axial direction of the bridge above the superstructure of the span to be removed and the span adjacent to the target span to be removed.

When the superstructure includes a steel main girder, in the reinforcing member installation step, the reinforcing member is installed on the web of the steel main girder of the superstructure in the span to be removed and the span adjacent to the span to be removed. You may install in the direction extended to the bridge axis direction of the said bridge.

A rail equipment installation step of installing rail equipment above the reinforcing member installed in the reinforcing member installing step is further provided, and in the crane installing step, the crane is installed on the rail equipment installed in the rail equipment installing step. You may make it install so that it can move along the said rail installation.

The reinforcing member installed in the reinforcing member installation step may be configured to also include a rail facility that allows the crane to move in the direction of the bridge axis of the bridge.

A crane moving step of moving the crane installed in the crane installing step to the vicinity of an end portion of the reinforcing member near the center of the removal target span, and in the removing step, the crane separated by the cutting step is provided. The predetermined portion of the superstructure may be removed by the crane moved in the crane moving step.

After the portion of the reinforcing member located above the predetermined portion of the superstructure cut off in the cutting step is separated from the other portion of the reinforcing member and removed, the predetermined portion of the superstructure is removed in the cutting step. You can separate it with .

In the removing step, not only the predetermined portion of the superstructure separated by the cutting step, but also the portion of the reinforcing member located above the predetermined portion may be removed at the same time.

In the cutting step, the superstructure may be cut after reducing a bending moment at the cutting position of the superstructure.

The cutting step may employ a jack in reducing the bending moment of the superstructure at the cut location.

INDUSTRIAL APPLICABILITY According to the bridge superstructure removal method according to the present invention, it is possible to provide a bridge superstructure removal method that can greatly relax restrictions on the use of the space under the girder when removing the bridge superstructure.

Side view schematically showing the bridge 60 to be removed from the superstructure (side view seen from the direction perpendicular to the bridge axis) FIG. 2 is a side view schematically showing a representative process when removing a superstructure 62 of a bridge 60 using the bridge superstructure removal method according to the first embodiment (a side view seen from a direction perpendicular to the bridge axis). FIG. 2 is a front view schematically showing a state in which the installation of the reinforcing member 10 and the mobile crane 20 required for the bridge superstructure removal method according to the first embodiment is completed (front view seen from the bridge axis direction). A front view showing a state in which holes 66A are discretely provided in a portion of the existing floor slab 66 of the superstructure 62 located above the existing main girder 64 (front view viewed from the bridge axis direction). FIG. 2 is a side view schematically showing one step of the bridge superstructure removal method according to the first embodiment of the present invention. FIG. 2 is a side view schematically showing one step of the bridge superstructure removal method according to the first embodiment of the present invention. FIG. 2 is a side view schematically showing one step of the bridge superstructure removal method according to the first embodiment of the present invention. FIG. 2 is a side view schematically showing one step of the bridge superstructure removal method according to the first embodiment of the present invention. FIG. 2 is a side view schematically showing one step of the bridge superstructure removal method according to the first embodiment of the present invention. FIG. 2 is a side view schematically showing one step of the bridge superstructure removal method according to the first embodiment of the present invention. FIG. 2 is a side view schematically showing one step of the bridge superstructure removal method according to the first embodiment of the present invention. FIG. 4 is a side view schematically showing one method of reducing the bending moment at the cutting position 62X of the superstructure 62; FIG. 4 is a side view schematically showing one method of reducing the bending moment at the cutting position 62X of the superstructure 62; FIG. 11 is a side view schematically showing a state in which, after the superstructure 62 is cut at the cutting position 62X, the joining member 12 is also provided at a portion near the center of the removal target span 68 of the reinforcing member 10, and the center hole jack 96 is removed; FIG. 3 is a front view schematically showing a state in which installation of a reinforcing member 10 and a mobile crane 20, which are necessary when carrying out the bridge superstructure removal method according to the second embodiment, is completed (front view seen from the direction of the bridge axis). FIG. 11 is a front view schematically showing a state in which the installation of the reinforcing member 30 and the mobile crane 20 required for the method of removing the bridge superstructure according to the third embodiment is completed (front view seen from the direction of the bridge axis). Front view (front view seen from the bridge axis direction) showing a mode in which the reinforcement member 30 (steel member 30A having a T-shaped cross section) is mechanically connected to the web 64C of the existing main girder 64 with bolts and nuts 32. Front view (front view seen from the bridge axis direction) showing a mode in which the reinforcing member 30 (flat bar 30B) is mechanically connected to the web 64C of the existing main girder 64 by welding. FIG. 11 is a front view (front view seen from the direction of the bridge axis) schematically showing a state in which the installation of the reinforcing member 30 and the mobile crane 20 required for the method of removing the bridge superstructure according to the fourth embodiment is completed;

Hereinafter, a method for removing a bridge superstructure according to an embodiment of the present invention will be described in detail with reference to the drawings.

(1) First Embodiment The first embodiment of the bridge superstructure removal method according to the present invention is an embodiment in which the existing main girders and existing floor slabs of the superstructure of the span to be removed are removed simultaneously.

(1-1) Outline Description FIG. 1 is a side view (side view seen from the direction perpendicular to the bridge axis) schematically showing a bridge 60 from which the superstructure is to be removed. A bridge 60 whose superstructure is to be removed is a three-span continuous bridge in which a superstructure 62 is constructed on substructures 74, 76, 78, and 80. In the following description, it is constructed on substructures 76 and 78. It is assumed that the part of the superstructure 62 located in the removal target span 68 between the substructures 76 and 78 (hereinafter sometimes referred to as the removal target superstructure part 62A) is to be removed. However, the bridges to which the present invention is applied are not limited to continuous bridges. In addition, the present invention can be applied to the substructures located at both ends of the span to be removed, whether they are piers or abutments. can be applied regardless of 1, the description of the existing floor slab 66 (see FIG. 3) of the superstructure 62 is omitted.

In FIG. 1, the adjacent span 70 is the span located to the left of the target span 68 to be removed (the span between the substructures 74 and 76), and the adjacent span 72 is the span 68 to be removed. This is the span located on the right side (the span between the substructures 78 and 80).

In addition, the bridge 60 is an overpass, and below the removal target span 68 of the bridge 60, the road 82 extends in a direction substantially orthogonal to the bridge axis direction of the bridge 60, which will be clarified later. As described above, in the bridge superstructure removal method according to the first embodiment, the superstructure part 62A to be removed can be removed only by working from above the bridge surface, and the influence on the space under the girder including the road 82 is reduced. The bridge superstructure removal construction method according to the first embodiment can be carried out in a state of being suppressed as much as possible. Note that the bridges to which the present invention is applied are not limited to overpasses, and the present invention can be suitably applied to overpasses and the like.

In the following explanation, the bridge 60 from which the superstructure is to be removed is a steel bridge, and the existing main girder 64 (see FIG. 3) of the superstructure 62 to be removed is a steel girder. The bridges to which the invention is applied are not limited to steel bridges.

FIG. 2 is a side view (viewed from a direction perpendicular to the bridge axis) schematically showing a typical process of removing the superstructure 62 of the bridge 60 using the bridge superstructure removal method according to the first embodiment. side view). 2, the description of the existing floor slab 66 (see FIG. 3) of the superstructure 62 is omitted. FIG. 3 is a front view (viewed from the direction of the bridge axis) schematically showing a state in which installation of the reinforcing member 10 and the mobile crane 20 required for the bridge superstructure removal method according to the first embodiment is completed. front view).

When carrying out the bridge superstructure removal method according to the first embodiment, as shown in FIGS. 2 and 3, the reinforcing member 10 is arranged above the superstructure 62 so as to extend in the axial direction of the bridge 60. Then, the reinforcing member 10 is attached to the upper surface of the upper flange 64A of the existing main girder 64 of the superstructure 62 with the joining member 12 to reinforce the superstructure 62 . When removing the superstructure part 62A to be removed, the superstructure part 62A to be removed is cut in the direction perpendicular to the bridge axis. In comparison, the distribution of the acting cross-sectional force of the superstructure 62 changes, and depending on the weight of the equipment and materials used for removing the crane or the like installed on the superstructure 62, the superstructure 62 may have insufficient load bearing capacity. . That is, the reinforcing member 10 is a member attached to the superstructure 62 in order to compensate for the lack of load bearing capacity of the superstructure 62 itself caused by cutting the superstructure 62 to a level at which safety can be ensured. The material and structure of 10 are not particularly limited, and specifically, for example, steel members of truss structure, plate girders, and steel box girders can be used as reinforcing member 10 as long as they can achieve the above purpose. can.

As shown in FIG. 2, the reinforcing member 10 is arranged in the span 68 to be removed and the adjacent spans 70, 72 centering on both ends of the span 68 to be removed (positions above the substructures 76, 78). It is a position that straddles each.

The joint members 12 for attaching the reinforcing member 10 to the superstructure 62 are provided with holes 66A (Fig. 4 ), and the lower surface of the reinforcement member 10 and the upper flange 64A of the existing main girder 64 are connected by the joint member 12. As shown in FIG. Specifically, as the joining member 12, for example, a steel material obtained by reinforcing a steel material having an H-shaped cross section with a rib steel plate can be used. The manner of connection between the reinforcing member 10 and the joint member 12 and the manner of connection between the existing main girder 64 and the joint member 12 are not particularly limited as long as sufficient joint strength can be obtained. A mechanical connection or the like using a nut or the like can be employed.

A rail facility 14 extending in the direction of the bridge axis is provided on the upper surface of the reinforcing member 10, and the rail facility 14 is provided with a mobile crane 20 capable of moving on the rail facility 14 in the direction of the bridge axis. The form of connection between the rail equipment 14 and the reinforcing member 10 is not particularly limited as long as a sufficient joint strength can be obtained. Specifically, for example, a mechanical connection using bolts and nuts, etc., is adopted. be able to. In the first embodiment, the reinforcing member 10 and the rail equipment 14 are separate members, but the reinforcing member 10 may also function as the rail equipment so that the reinforcing member 10 also serves as the rail equipment. Specifically, for example, the rail equipment 14 may be attached to the reinforcing member 10 in advance, and the rail equipment 14 may be installed simultaneously with the installation of the reinforcing member 10 .

When removing the predetermined removal portion 62A1 of the removal target superstructure portion 62A (the end portion near the center of the removal target span 68 of the removal target superstructure portion 62A), the mobile crane 20 is placed on the reinforcing member 10. It is moved to the vicinity of the central end of the span 68 to be removed, and at that position, the mobile crane 20 supports the predetermined removal portion 62A1 of the superstructure portion 62A to be removed (the mobile crane on the right side of FIG. 2). crane 20), the predetermined removal portion 62A1 is separated, and the separated predetermined removal portion 62A1 is lifted and removed by the mobile crane 20 (see the mobile crane 20 on the left side of FIG. 2).

After completing the removal of the predetermined removal portion 62A1 of the removal target superstructure portion 62A, the mobile crane 20 is pulled back in the direction of the end of the removal target span 68 (direction approaching the substructures 76, 78) to remove the superstructure portion to be removed. A part to be removed 62A2 next to 62A is separated and removed. When separating and removing the next part to be removed 62A2, the end part 10A of the reinforcing member 10 located above the next part to be removed 62A2 may be removed at the same time, or the next part to be removed 62A2 may be removed. After removing the end portion 10A of the reinforcing member 10 located above, the next removal target portion 62A2 may be removed.

(1-2) Description of Each Process FIGS. 5 to 11 are side views schematically showing each process of the bridge superstructure removal method according to the first embodiment of the present invention. is a side view seen from the side (perpendicular to the bridge axis). 5 to 11, the description of the existing floor slab 66 (see FIG. 3) of the superstructure 62 is omitted.

Each step (steps S1 to S6) of the bridge replacement construction method according to the present embodiment will be described with reference to FIGS. 5 to 11. FIG.

<Step S1>
As shown in FIG. 5, the reinforcing member 10 extends in the longitudinal direction of the bridge 60 above a predetermined range of the superstructure 62 (a predetermined range centered on positions above the substructures 76 and 78). and attached to the existing main girder 64 of the superstructure 62 with the joint members 12 (see FIGS. 2 and 3) to reinforce the superstructure 62, and as shown in FIG. A counterweight 50 is provided above the portion of the superstructure 62 of the bridge 60 (the portion near the substructures 74 and 80) as a weight for preventing the superstructure 62 of the bridge 60 from overturning. However, the counterweight 50 need not be provided if the superstructure 62 is already prevented from tipping over by another configuration. Further, instead of providing the counterweight 50, the ends of the superstructure 62 are connected to the ends of the superstructures 84 and 86 adjacent to the superstructure 62, respectively, thereby making the superstructure of the bridge 60 continuous. may

<Step S2>
After attaching the reinforcing member 10 to a predetermined range of the superstructure 62 in step S1 and providing the counterweight 50 as necessary, as shown in FIG. , the superstructure 62 is cut in the direction perpendicular to the bridge axis. A wire saw, wall saw, gas cutting, or the like may be used to cut the superstructure 62 . In the case of steel main girders having bolted joints, "cutting" the superstructure 62 also includes removing the bolted joints to separate the steel main girders that have been connected in the bridge axis direction.

When cutting the superstructure 62, it is preferable from the standpoint of safety to cut in a state in which the bending moment at the cutting position 62X is reduced. Specifically, when reducing the bending moment at the cutting position 62X, for example, as shown in FIG. , a jack 90 is placed between the attached brackets 88 to apply tensile force to the upper flange 64A of the existing main girder 64 (upper flange 64A near the cutting position 62X), and the existing main girder 64 of the superstructure 62 A bracket 92 is attached to the lower surface of the lower flange 64B so as to sandwich the cut position 62X, a center hole jack 94 is fixed to the outer surface of the attached bracket 92 in the bridge axis direction, and the lower flange 64B of the existing main girder 64 (cut A compressive force may be applied to the lower flange 64B) near location 62X. However, before applying the tensile force and the compressive force, the stiffener 64D is placed vertically between the brackets 88 and 92, and the side of the stiffener 64D is attached to the web 64C of the existing main girder 64. , the upper end of the stiffener 64D is attached to the lower surface of the upper flange 64A of the existing main girder 64, and the lower end of the stiffener 64D is attached to the upper surface of the lower flange 64B of the existing main girder 64. In FIG. 12, reference numeral 94A denotes a tension rod of the center hole jack 94, and reference numeral 94B denotes a fixing member of the center hole jack 94. As shown in FIG.

In addition, as shown in FIG. 13, the joining member 12 is not provided at a portion near the center of the removal target span 68 of the reinforcing member 10, and the end portion near the center of the removal target span 68 of the reinforcing member 10 is removed. and the part of the superstructure 62 below it, a center hole jack 96 is provided in the vertical direction to apply force in a direction to bring them closer together, and an upward force is applied to the central part of the superstructure 62 to cut. The superstructure 62 may be cut in the direction perpendicular to the bridge axis at the cutting position 62X with the bending moment at the position 62X reduced. In this case, after cutting the superstructure 62 in the direction perpendicular to the bridge axis at the cutting position 62X, as shown in FIG. The member 12 is provided and the center hole jack 96 is removed.

<Step S3>
A mobile crane 20 is attached to the rail equipment 14 (see FIG. 2) provided on the reinforcing member 10, and the mobile crane 20 is moved near the center end of the removal target span 68 of the reinforcing member 10, At that position, with the mobile crane 20 supporting the predetermined removal portion 62A1 of the superstructure portion 62A to be removed (see the mobile crane 20 on the right side of FIG. 7), the predetermined removal portion 62A1 is separated, and the separated predetermined removal is performed. The portion 62A1 is lifted by the mobile crane 20 and removed (see the left mobile crane 20 in FIG. 7).

When removing the predetermined removal portion 62A1 of the superstructure portion 62A to be removed, as schematically shown in FIG. It is moved to a position near the center of the adjacent spans 70 and 72 along the rail equipment 14, and the predetermined removal portion 62A1 on the truck 22 is moved to a trailer by the crane 24 provided on the superstructure 62 of the adjacent spans 70 and 72. 26 to be loaded and removed.

<Step S4>
After completing the removal of the predetermined removal portion 62A1 of the removal target superstructure portion 62A, the mobile crane 20 is pulled back in the direction of the end of the removal target span 68 (direction approaching the substructures 76, 78) to remove the superstructure portion to be removed. The next part to be removed 62A2 of 62A is separated and removed, but before separating the next part to be removed 62A2, as shown in FIG. Remove portion 10A. After that, the next part to be removed 62A2 of the superstructure 62 is removed.

When cutting off and removing the next part to be removed 62A2, the end part 10A of the reinforcing member 10 located above the next part to be removed 62A2 may be removed at the same time.

<Step S5>
Step S4 is repeated to remove all of the superstructure parts 62A to be removed located in the span 68 to be removed. FIG. 10 is a side view schematically showing a state after removal of all of the superstructure part 62A to be removed located in the span 68 to be removed is finished.

<Step S6>
After removing all of the superstructure part 62A to be removed located in the span 68 to be removed in step S5, the reinforcing member 10 and the mobile crane 20 remaining on the superstructure 62 in the adjacent spans 70 and 72 are removed. After removal, the bridge superstructure removal method according to the first embodiment is completed. FIG. 11 is a side view schematically showing a state after the bridge superstructure removal method according to the first embodiment has been applied to the bridge 60. As shown in FIG.

(1-3) Effects As described above, the reinforcing member 10, the joint member 12, the rail equipment 14, the mobile crane 20, and the truck, which are the equipment used in the bridge superstructure removal method according to the first embodiment. 22, crane 24, and trailer 26 are all located above the existing main girder 64 of the superstructure 62, and the method for removing the superstructure of the bridge according to the first embodiment requires only work from above the bridge surface. The removal target superstructure part 62A of the bridge 60 can be removed.

In addition, in the first embodiment, after the reinforcing member 10 is attached to the predetermined range of the superstructure 62 in step S1, the mobile crane 20 is installed in step S3, and the reinforcing member 10 is attached to the mobile crane 20 It is provided so that the load-bearing capacity can be secured even for the weight of

(2) Second Embodiment The first embodiment described above is an embodiment in which the existing main girder 64 and the existing floor slab 66 of the superstructure 62 (removal target superstructure portion 62A) of the removal target span 68 are removed at the same time. However, in the second embodiment of the bridge superstructure removal method according to the present invention, the existing main girder 64 is removed after removing the existing floor slab 66 of the superstructure part 62A to be removed. This embodiment is carried out when removing the existing main girder 64 remaining after the removal of the existing floor slab 66 .

In the first embodiment, both the existing main girder 64 and the existing floor slab 66 are removed. The object to be removed by the superstructure removal method is the existing main girder 64 remaining after the removal of the existing floor slab 66, which is different from the bridge superstructure removal method according to the first embodiment. The bridge superstructure removal method according to the embodiment is the same as the bridge superstructure removal method according to the first embodiment.

In the bridge superstructure removal method according to the second embodiment, the existing floor slab 66 is first removed, and then the reinforcing member 10 for reinforcing the existing main girder 64 is placed on the upper flange 64A of the existing main girder 64. However, the existing floor slab 66 of the superstructure part 62A to be removed can be removed by a general floor slab removal method that is currently used, and can be removed only from the bridge surface. can.

FIG. 15 is a front view (from the direction of the bridge axis) schematically showing a state in which the installation of the reinforcing member 10 and the mobile crane 20 required for the bridge superstructure removal method according to the second embodiment is completed. front view). Since the reinforcing member 10 and the mobile crane 20 are installed after removing the existing floor slab 66 of the superstructure part 62A to be removed, as shown in FIG. In the construction method, the existing floor slab 66 has already been removed before the implementation.

(3) Third Embodiment In the first and second embodiments described above, the upper flange 64A of the existing main girder 64 of the superstructure 62 is reinforced by attaching the reinforcing member 10 to the upper flange 64A via the joint member 12. In the third embodiment of the bridge superstructure removal method according to the present invention, as shown in FIG. In this embodiment, the existing main girder 64 is reinforced by attaching the reinforcing member 30 to the web 64C of the main girder 64 in the direction extending in the bridge axis direction of the bridge 60, and then the superstructure part 62A to be removed is removed. . Therefore, the rail equipment 14 is arranged on the existing floor slab 66 of the superstructure 62, as shown in FIG.

Except for these points, the third embodiment is the same as the first embodiment, and in the third embodiment, the existing main girder 64 and the existing floor slab 66 are simultaneously removed as in the first embodiment. form.

The reinforcing member 30 is attached to the web 64C of the existing main girder 64 of the superstructure part 62A to be removed. This is the position near and above the flange 64B.

The manner in which the reinforcing member 30 is attached to the web 64C of the existing main girder 64 is not particularly limited as long as sufficient joint strength can be obtained. Specifically, for example, as shown in FIG. A T-shaped steel member 30A is mechanically connected to the web 64C of the existing main girder 64 using bolts and nuts 32, and as shown in FIG. A mode of connecting to the web 64C of the main girder 64 by welding or the like can be adopted.

The reinforcing member 30 is transported on the superstructure 62, and by providing an opening through which the reinforcing member 30 can pass in a part of the existing floor slab 66, the existing main girder 64 to be attached without using the space under the girder. , and can be installed at a predetermined position on the existing main girder 64 using a suspended scaffold or the like. In addition, the reinforcing member 30 is carried onto the superstructure 62 using the space under the girder of the adjacent span 70 and the adjacent span 72, and installed at a predetermined position of the existing main girder 64 using a suspended scaffold or the like. It is also possible to

(4) Fourth Embodiment The third embodiment described above is an embodiment in which the existing main girder 64 and the existing floor slab 66 of the superstructure 62 (removal target superstructure portion 62A) of the removal target span 68 are removed at the same time. However, in the fourth embodiment of the bridge superstructure removal method according to the present invention, the existing main girder 64 is removed after removing the existing floor slab 66 of the superstructure part 62A to be removed. This embodiment is carried out when removing the existing main girder 64 remaining after the removal of the existing floor slab 66 .

In the third embodiment, both the existing main girder 64 and the existing floor slab 66 are removed. The object to be removed by the superstructure removal method is the existing main girder 64 remaining after the removal of the existing floor slab 66, which is different from the bridge superstructure removal method according to the third embodiment. The bridge superstructure removal method according to the embodiment is the same as the bridge superstructure removal method according to the third embodiment. In this embodiment, the reinforcing member 30 is attached to the web 64C of 64 to reinforce the existing main girder 64, and then the existing main girder 64 of the superstructure part 62A to be removed is removed.

In the bridge superstructure removal method according to the fourth embodiment, after the existing floor slab 66 is removed or in parallel with the removal of the existing floor slab 66, the reinforcing member 30 is attached to the web 64C of the existing main girder 64. The existing main girder 64 is reinforced by installing it, but the existing floor slab 66 of the superstructure part 62A to be removed can be removed by the general floor slab removal method currently used. Removal can be done only by the work of

FIG. 19 is a front view (viewed from the direction of the bridge axis) schematically showing a state in which installation of the reinforcing member 30 and the mobile crane 20, which are necessary for the bridge superstructure removal method according to the fourth embodiment, has been completed. front view). Since the mobile crane 20 is installed after removing the existing floor slab 66 of the superstructure part 62A to be removed, as shown in FIG. The existing floor slab 66 has already been removed before the implementation.

In addition, in the fourth embodiment, the aspect of attaching the reinforcing member 30 to the web 64C of the existing main girder 64 is the same as in the third embodiment.

DESCRIPTION OF SYMBOLS 10, 30... Reinforcement member 10A... End part 12... Joint member 14... Rail installation 20... Mobile crane 22... Carriage 24... Crane 26... Trailer 30A... Steel member of T-shaped cross section 30B... Flat bar 32... Bolt and nut 50... Counterweight 60... Bridge 62, 84, 86... Superstructure 62A... Superstructure part to be removed 62A1... Predetermined removal part 62A2... Next part to be removed 62X... Cutting position 64... Existing main girder 64A... Upper flange 64B... Lower Flange 64C Web 64D Stiffener 66 Existing floor slab 66A Hole 68 Spans to be removed 70, 72 Adjacent spans 74, 76, 78, 80 Substructure 82 Roads 88, 92 Brackets 90 Jacks 94, 96 Center hole jack 94A Tension rod 94B Fixing body

Claims (9)

A bridge superstructure removal method for removing a superstructure of a bridge having an existing main girder by cutting a predetermined position of the superstructure,
A reinforcing member for reinforcing the superstructure of the span to be removed and the adjacent span adjacent to the span to be removed extends in the axial direction of the bridge so as to straddle the span to be removed and the adjacent span. A step of installing a reinforcing member installed in a direction;
a crane installation step of installing a crane above the superstructure;
The crane installed in the crane installation step cuts the predetermined position of the superstructure in the removal target span while supporting the predetermined portion of the superstructure to be removed in the removal target span. process and
a removing step of removing the predetermined portion of the superstructure separated by the cutting step with the crane;
A bridge superstructure removal method characterized by having A bridge superstructure removal method for removing a superstructure of a bridge having an existing main girder by cutting a predetermined position of the superstructure,
A reinforcing member for reinforcing the superstructure of the span to be removed and the adjacent span adjacent to the span to be removed extends in the axial direction of the bridge so as to straddle the span to be removed and the adjacent span. A step of installing a reinforcing member installed in a direction;
a crane installation step of installing a crane above the superstructure;
First brackets are attached to the upper flange of the existing main girder of the span to be removed at different positions sandwiching the predetermined position of the superstructure, and a jack is placed between the attached first brackets. In addition, second brackets are attached to the lower flange of the existing main girder in the span to be removed at different positions sandwiching the predetermined position of the superstructure, and the attached second brackets are attached to each other. a jack is arranged between them, stiffeners having side portions attached to the web of the existing main girder are arranged vertically between the first bracket and the second bracket positioned vertically, respectively; After placing the stiffeners, the jacks placed between the first brackets are extended to apply tensile force to the upper flanges of the existing main girder and placed between the second brackets. a bending moment reduction step of contracting the jack to apply a compressive force to the lower flange of the existing main girder to reduce the bending moment of the superstructure at the predetermined position;
a cutting step of cutting the predetermined position of the superstructure with the bending moment reduced in the bending moment reducing step;
a removal step of removing a predetermined portion of the superstructure separated by the cutting step with the crane;
A bridge superstructure removal method characterized by having In the reinforcing member installation step, the reinforcing members are dispersed above the superstructure between the span to be removed and the adjacent span in a direction extending in the axial direction of the bridge on the upper surface of the upper flange of the existing main girder. 3. The method for removing a bridge superstructure according to claim 1 or 2, wherein the bridge superstructure is installed through joint members that are arranged at intervals . In the reinforcing member installing step, the reinforcing member is installed on the web of the existing main girder of the superstructure between the span to be removed and the adjacent span in a direction extending in the axial direction of the bridge. The bridge superstructure removal construction method according to claim 1 or 2. further comprising a rail facility installation step of installing a rail facility above the reinforcing member installed in the reinforcing member installing step;
4. The bridge according to any one of claims 1 to 3 , wherein in the crane installation step, the crane is installed on the rail equipment installed in the rail equipment installation step so as to be movable along the rail equipment. Superstructure removal method. 4. The method for removing a bridge superstructure according to claim 3, wherein the reinforcing member installed in the reinforcing member installing step also includes a rail facility that enables the crane to move in the direction of the bridge axis of the bridge. . further comprising a crane moving step of moving the crane installed in the crane installing step to the vicinity of the end of the reinforcing member near the center of the removal target span;
7. The bridge superstructure according to claim 5 or 6, wherein in the removing step, the predetermined portion of the superstructure separated in the cutting step is removed by the crane moved in the crane moving step. Removal method. After the portion of the reinforcing member located above the predetermined portion of the superstructure cut off in the cutting step is separated from the other portion of the reinforcing member and removed, the predetermined portion of the superstructure is removed in the cutting step. 4. The bridge superstructure removal construction method according to claim 3 , wherein the bridge superstructure is separated by . 4. The method according to claim 3 , wherein in the removing step, not only the predetermined portion of the superstructure separated by the cutting step but also the portion of the reinforcing member located above the predetermined portion is removed at the same time. Bridge superstructure removal method.

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