JP6902184B2 - Work equipment and overhang erection method - Google Patents

Description

The present invention relates to a working device used for an overhanging erection method of a bridge girder, and also relates to an overhanging erection method using the working device.

The overhanging erection method is a method of extending the bridge girder by constructing a new block so as to extend forward from the tip of the existing portion of the bridge girder in the direction of the bridge axis (for example, FIGS. 15 to 17 of Patent Document 1). reference). Hereinafter, the reference numerals used in Patent Document 1 are shown in parentheses, and the techniques described in Patent Document 1 will be briefly described.

As described in Patent Document 1, in implementing the overhanging erection method, first, piers (100, 120) are constructed. Subsequently, bracket support (110) is installed on both sides of the pier (100), the formwork (111) is assembled on the bracket support (110), and concrete is placed in the formwork (111). The stigma (121) is constructed on the piers (100, 120). The stigma (121) projects from above the piers (100, 120) in the direction of the bridge axis, and a large-scale bracket support (110) is installed to construct such a stigma (121). There is a need to.

After the stigma (121) is constructed, the formwork (111) and the bracket support (110) are removed. Further, by installing the work vehicle (10a) on the overhanging portion (121a) of the stigma (121), a part of the work vehicle (10a) is extended from the overhanging portion (121a) of the stigma (121). put out. Then, the work pedestal (122) and the formwork pedestal (123) are hung from the work vehicle (10a), and a part of the work pedestal (122) and the formwork pedestal (123) is overhanging the stigma (121). Let it go under (121a). Then, after the formwork is installed on the formwork base (123), concrete is poured into the formwork. As a result, the block (131) is constructed so as to project forward in the bridge axis direction from the tip of the overhanging portion (121a) of the stigma (121). After that, the bridge girder is extended by advancing the work vehicle (10a) every time the block is constructed and constructing the blocks in sequence.

Japanese Unexamined Patent Publication No. 2004-218316

By the way, in the technique described in Patent Document 1, it takes time to install and remove the large-scale bracket support (110), so that the construction period becomes long.
In order to shorten the construction period, it is conceivable to reduce the bracket support (110) to a small scale and construct a stigma (121) without an overhang (121a). However, due to the balance of the work vehicle (10a), the wheels of the work vehicle (10a) cannot be arranged in front of the stigma (121) in the bridge axis direction. Therefore, when the stigma (121) without the overhanging portion (121a) is constructed, the suspended work pedestal (122) hits the piers (100, 120).

The present invention has been made in view of the above circumstances, and even if a work pedestal is suspended by using a work vehicle installed on a stigma without an overhang, if the work pedestal hits a pier or an abutment. To avoid it.

In order to solve the above problems, the work device used in the overhang erection method for extending the bridge girder in the bridge axis direction is supported on the existing portion of the bridge girder and overhangs from the existing portion to the extension side in the bridge axis direction. A work vehicle, a first cross beam extending in the width direction of the bridge, and a first cross beam provided in a portion of the work car protruding from the existing portion, an extension jig installed on the first cross beam, and the above. A work stand suspended from the extension jig is provided, and the extension jig extends in the bridge axis direction and is provided on the first cross beam, and extends in the bridge axis direction from the first cross beam. A vertical beam overhanging to the side, a second horizontal beam guided by the vertical beam in the bridge axis direction, extending in the bridge width direction, and supporting the work pedestal in a suspended state, and the second cross beam. It has a drive unit for moving between a position on the extension side in the bridge axis direction with respect to the first cross beam and a position aligned with the first cross beam.

The overhanging erection method of extending the bridge girder using the work device includes a beam head construction step of constructing a beam head as a part of the bridge girder on a beam pedestal or a bridge stand, and supporting the work vehicle on the column head. At the same time, the work vehicle is extended from the column head to the extension side in the bridge axis direction, and the first cross beam is extended from the existing portion of the work vehicle so as to extend the first cross beam in the bridge width direction. It is provided on the overhanging portion, the vertical beam is provided on the first cross beam so as to extend in the bridge axis direction, the vertical beam is provided on the extension side in the bridge axial direction from the first cross beam, and the second cross beam is provided. The second cross beam is positioned on the extension side of the first cross beam in the bridge axial direction so as to extend in the bridge width direction and to guide the second cross beam in the bridge axial direction by the vertical beam. A first block as a part of the bridge girder is constructed on the extension side of the column head in the bridge axis direction and above the work frame, and an assembly step of suspending the work frame from the second cross beam. The one-block construction step, the relocation step of moving the work vehicle from the top of the beam onto the first block, and the relocation step of extending the work vehicle from the first block to the extension side in the bridge axis direction, and the above. A retreat step of moving the second cross beam to a position aligned with the first cross beam by a drive unit, and a second as a part of the bridge girder on the extension side of the first block in the bridge axial direction and above the work pedestal. It includes a second block construction step of constructing a block.

According to the above, when the second cross beam of the extension jig is located on the extension side in the bridge axial direction with respect to the first cross beam by the drive unit, the work pedestal suspended from the second cross beam of the extension jig becomes the pier. Does not contact. Therefore, the work pedestal does not tilt, and the first block can be constructed on the bridge axial extension side of the stigma by working on the work pedestal.
On the other hand, when the second cross beam of the extension jig is retracted to a position where the second cross beam is aligned with the first cross beam by the drive unit, the suspended work stand enters under the first block. Therefore, it is possible to work on the work platform and construct the second block on the bridge axial extension side of the first block.

The overhanging erection method further includes a step of installing a bracket on the opposite surface of the stigma on the extension side in the bridge axial direction, and in the assembly step, the work vehicle is supported by the bracket by an anchor.

According to the above, a rotational force that causes the work vehicle to fall toward the extension side in the bridge axial direction due to the load of the work vehicle and the work platform is received by the bracket via the anchor. Therefore, the work vehicle is stably supported on the stigma.

Preferably, the work pedestal can be suspended from the second cross beam to the first cross beam. More preferably, the extension jig is removable from the first cross beam.

According to the above, the extension jig can be attached to a work vehicle different from the work vehicle. That is, the extension jig can be used for a plurality of work vehicles.

According to the present invention, even if a work pedestal is suspended by using a work vehicle installed on a stigma without an overhang, the work pedestal can be prevented from hitting a pier or an abutment.

FIG. 1 is a side view of the working device. FIG. 2 is a side view showing a process of constructing a pier and a stigma. FIG. 3 is a side view showing a process of attaching a bracket to the stigma. FIG. 4 is a side view showing a process of installing the rail on the stigma. FIG. 5 is a side view showing a process of assembling the work vehicle and the extension jig. FIG. 6 is a side view showing a process of constructing a block of a bridge girder. FIG. 7 is a side view showing a process of advancing the rail. FIG. 8 is a side view showing a process of advancing the work vehicle. FIG. 9 is a side view showing a process of retracting the cross beam of the extension jig and suspending the work pedestal and the formwork pedestal from the cross beam of the extension jig to the cross beam of the work vehicle. FIG. 10 is a side view showing a process of removing the extension jig. FIG. 11 is a side view showing a process of constructing a block of a bridge girder. FIG. 12 is a side view showing a process of advancing the rail. FIG. 13 is a side view showing a process of advancing the work vehicle. FIG. 14 is a side view showing a process of assembling an extension jig and another work vehicle on the opposite side.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, although the embodiments described below are provided with various technically preferable limitations for carrying out the present invention, the scope of the present invention is not limited to the following embodiments and illustrated examples.

<1. Work equipment>
FIG. 1 is a side view of a work device 10 used in an overhang erection method for constructing a bridge girder. The overhanging erection method is a method of extending the bridge girder in the bridge axis direction by constructing the new block so as to project the new block in the bridge axis direction from the existing portion of the bridge girder using the work device 10. Here, in the following, the "bridge axis direction" may be referred to as "front-back direction" and the "bridge width direction" may be referred to as "left-right direction". In the "front-back direction", the direction from the pier or abutment to the tip of the existing part of the bridge girder is "forward", and the direction from the tip of the existing part of the bridge girder to the pier or abutment is "rear". Since "forward" is the direction in which the bridge girder is extended, the "front side in the bridge axis direction" means the "extension side in the bridge axis direction".

First, the working device 10 will be described.
The work device 10 includes a pair of rails 20, a plurality of anchors 21, a work vehicle 30, a plurality of anchors 36, an extension jig 40, a work pedestal (scaffolding) 50, a formwork cradle 60, and the like.

The pair of rails 20 extend in the bridge axis direction at intervals in the bridge width direction (direction perpendicular to the paper surface of FIG. 2), and are provided by anchors 21 on the installation surface 9 via a plurality of sleepers 22. It is installed. The installation surface 9 is the upper surface of the existing portion of the bridge girder.

The work vehicle 30 includes a pair of left and right main structures 31, a first front cross beam 32, a first rear cross beam 33, a pair of left and right front sliding bodies 34, and a pair of left and right rear sliding bodies 35. Have.

The pair of main structures 31 are arranged parallel to each other at intervals in the bridge width direction. The main structure 31 is a truss structure formed into a substantially parallelogram when viewed from the side surface, and the truss structure surface of the main structure 31 is directed in the bridge width direction.

The pair of main structures 31 are connected to each other by a front cross beam 32 and a rear cross beam 33 bridged between the upper portions thereof. The cross beams 32 and 33 are longer than the width of the bridge girder, and both ends of the cross beams 32 and 33 project outward from the bridge girder in the bridge width direction. The upper ends of the suspension members (for example, steel rods and shaped steel) 38 are fixed to both ends of the front cross beam 32, and the suspension members 38 hang down from the front cross beam 32 further below the installation surface 9. Similarly, the suspending member 39 hangs down from both ends of the rear cross beam 33.

Sliding bodies 34 and 35 having rollers and the like are attached to the front and rear ends of the lower portion of the main structure 31 via jacks. The sliding bodies 34 and 35 engage with the rail 20 and can slide with respect to the rail 20, and the sliding bodies 34 and 35 allow the work vehicle 30 to move on the rail 20 in the direction of the bridge axis.

Further, the main structure 31 of the work vehicle 30 is fixed to the existing portion of the bridge girder by the anchor 36. Here, in a state where the rail 20 is fixed to the bridge girder by the anchor 21 and the main structure 31 is released from the anchor 36, the work vehicle 30 can be moved in the bridge axis direction by the rail 20 and the sliding bodies 34 and 35. .. On the other hand, in a state where the work vehicle 30 is fixed by the anchor 36 and the rail 20 is released from the anchor 21, the rail 20 can be moved in the bridge axis direction.

An extension jig 40 is installed on the cross beams 32 and 33. The extension jig 40 is removable from the cross beams 32 and 33.

The extension jig 40 includes a pair of left and right vertical beams 41, a second front cross beam 42, a second rear cross beam 43, a pair of left and right front traveling bodies 44, and a pair of left and right rear traveling bodies 45. A hydraulic jack 46 is provided.

The vertical beam 41 is erected between the front side cross beam 32 and the rear side cross beam 33 of the work vehicle 30, and is fixed to these cross beams 32 and 33 by fasteners such as bolts. The vertical beam 41 can be removed from the horizontal beams 32 and 33 by releasing the fastening with the fastener.

The vertical beam 41 is longer than the distance between the horizontal beam 32 and the horizontal beam 33, the front end of the vertical beam 41 projects forward from the front horizontal beam 32, and the rear end of the vertical beam 41 projects rearward from the rear horizontal beam 33. There is. Further, the front end of the vertical beam 41 projects forward from the front end of the work vehicle 30, that is, from the front end of the main structure 31.

The cross beams 42 and 43 are bridged between the left and right vertical beams 41, and are guided in the bridge axis direction by the vertical beams 41. The cross beams 42 and 43 are connected to each other by a stay 47 erected between them. The distance between the cross beams 42 and 43 is equal to the distance between the cross beams 32 and 33 of the work vehicle 30.

Here, at the lower end of the front cross beam 42, a pair of left and right front traveling bodies (for example, a chill tank with both roller guides) 44 that engage with the vertical beam 41 and can slide with respect to the vertical beam 41 are attached to the front side. The front cross beam 42 is guided on the vertical beam 41 in the bridge axis direction by the traveling body 44 and the vertical beam 41. Similarly, a pair of left and right rear traveling bodies 45 are provided at the lower ends of the rear cross beams 43 so that the rear cross beams 43 are guided on the vertical beams 41 in the bridge axis direction.

A hydraulic jack (drive unit) 46 that expands and contracts by flood control is provided between the rear horizontal beam 43 and the rear end of the vertical beam 41. The cross beams 42 and 43 move in the direction of the bridge axis due to the expansion and contraction of the hydraulic jack 46. In the extended state of the hydraulic jack 46, the cross beams 42 and 43 of the extension jig 40 are located on the front side in the bridge axis direction with respect to the cross beams 32 and 33 of the work vehicle 30. On the other hand, when the hydraulic jack 46 is contracted, the cross beams 42 and 43 are aligned with the cross beams 32 and 33 of the work vehicle 30, respectively.
Instead of the hydraulic jack 46, a hydraulic cylinder may be provided between the rear cross beam 43 and the rear end of the vertical beam 41, and the cross beams 42 and 43 may move in the bridge axis direction due to expansion and contraction of the hydraulic cylinder. Further, the cross beams 42 and 43 may be moved in the bridge axis direction by a hydraulic motor or an electric motor and a linear motion transmission mechanism instead of the hydraulic jack 46.

The cross beams 42 and 43 are longer than the width of the bridge girder, and both ends of the cross beams 42 and 43 project outward from the bridge girder in the bridge width direction. The upper ends of the suspending material (for example, steel rod, H-shaped steel) 48 are fixed to both ends of the front cross beam 42, and the suspending member 48 hangs down from the front cross beam 42 further below the installation surface 9. Similarly, the suspending member 49 hangs down from the rear cross beam 43.

A work stand 50 is attached to the lower ends of the hanging members 48 and 49. The work stand 50 is suspended from the cross beams 42 and 43 by the suspending members 48 and 49 and is maintained in a horizontal posture. A framework scaffold 70 is installed on the front portion of the work stand 50.

The work stand 50 can be replaced from the cross beams 42, 43 of the extension jig 40 to the cross beams 32, 33 of the work vehicle 30. That is, the work pedestal 50 was suspended from the cross beams 42, 43 of the extension jig 40 by the suspending members 48, 49, and the work pedestal 50 was suspended from the cross beams 32, 33 of the work vehicle 30 by the suspending members 38, 39. It can be changed to the state.

Further, a chain block hangs down from the cross beams 42 and 43, and the formwork cradle 60 is suspended by the chain block so that it can be raised and lowered independently of the work pedestal 50 at a position slightly higher than the work pedestal 50. The formwork cradle 60 is formed by assembling shaped steel in a grid pattern. A formwork for a bridge girder block can be installed on the formwork cradle 60.
The formwork cradle 60 can also be suspended from the cross beams 42 and 43 of the extension jig 40 to the cross beams 32 and 33 of the work vehicle 30.

<2. Overhang erection method using work equipment>
(1) Construction of pier and stigma First, as shown in FIG. 2, after constructing the pier 2, the stigma 3 is constructed on the pier 2. The stigma 3 is a component of the bridge girder and is the first block to be constructed. The stigma 3 does not project from the pier 2 in the bridge axis direction, and the length of the stigma 3 along the bridge axis direction is equal to the length of the pier 2 along the bridge axis direction.

(2) Installation of Bracket Next, as shown in FIG. 3, the bracket 80 is fixed to the surface of the stigma 3 on the rear side in the bridge axis direction. If the distance between the sliding bodies 34 and 35 of the work vehicle 30 is narrower than the length L of the stigma 3, the bracket 80 may not be installed.

(3) Assembling the work device Next, as shown in FIG. 4, the front ends of the left and right rails 20 are aligned with the front surface of the stigma 3 in the bridge axis direction, and the rear part of the rail 20 is the upper surface of the stigma 3. The rail 20 is laid on the upper surface of the stigma 3 via the sleepers 22 so as to extend rearward from the rail 20. Then, these rails 20 are fixed to the capital 3 and the bracket 80 by the anchor 21. Since the rear portion of the rail 20 projecting rearward from the stigma 3 is fixed to the bracket 80 by the anchor 21, the rail 20 is stable.

Next, as shown in FIG. 5, the work vehicle 30 is assembled on the rail 20, and the work vehicle 30 is fixed to the stigma 3 and the bracket 80 by the anchor 36. Here, when fixing the work vehicle 30, the front sliding body 34 is positioned at the front end of the rail 20, and the node on the upper front side of the main structure 31 and the front cross beam 32 are positioned in front of the stigma 3. Since the front sliding body 34 is located on the stigma 3, the work vehicle 30 is stably installed on the stigma 3.

Further, the extension jig 40 is assembled on the cross beams 32 and 33 of the work vehicle 30, and the vertical beam 41 of the extension jig 40 is fixed to the cross beams 32 and 33 of the work vehicle 30. Here, when fixing the vertical beam 41, the front end of the vertical beam 41 projects forward from the front horizontal beam 32 of the work vehicle 30, and the rear end of the vertical beam 41 protrudes behind the rear horizontal beam 33 of the work vehicle 30. Overhang on. When assembling the extension jig 40, the front cross beam 42 of the extension jig 40 is positioned in front of the front cross beam 32 of the work vehicle 30, and the rear cross beam 43 of the extension jig 40 is located behind the work vehicle 30. It is positioned in front of the cross beam 33 and the stigma 3, and the hydraulic jack 46 is in an extended state.

After installing the extension jig 40 as described above, the work pedestal 50 is suspended from the cross beams 42 and 43 of the extension jig 40 by the suspending members 48 and 49, and the framework scaffold 70 is installed on the work pedestal 50. Further, the formwork cradle 60 is suspended from the cross beams 42 and 43 of the extension jig 40 by the chain block. At this time, the work stand 50 and the formwork cradle 60 do not hit the stigma 3 or the pier 2. This is because the hydraulic jack 46 is in an extended state, and the cross beams 42 and 43 of the extension jig 40 are located in front of the cross beams 32 and 33 of the work vehicle 30.

Here, since the rail 20 and the work vehicle 30 are fixed to the bracket 80 by the anchors 21 and 36, the work is performed by the loads of the work vehicle 30, the extension jig 40, the work stand 50, the formwork cradle 60, and the framework scaffold 70. The bracket 80 receives a rotational force (see arrow A in FIG. 5) that causes the vehicle 30 to fall forward. Therefore, the work platform 30, the extension jig 40, the work stand 50, the formwork cradle 60, and the framework scaffold 70 are stable.

(4) Construction of block Next, the formwork is assembled on the formwork cradle 60, reinforcing bars are arranged, and concrete is placed in the formwork. As a result, as shown in FIG. 6, the block 4 which is a part of the bridge girder is constructed on the front side of the stigma 3, and the block 4 and the stigma 3 are integrated. The block 4 is a part of the bridge girder, and the construction of the block 4 extends the bridge girder to the front side in the bridge axial direction by the amount of the block 4. Since the rail 20 does not project forward from the stigma 3 during the construction of the block 4, the rail 20 does not interfere with the construction of the block 4.

(5) Advance of rail After the concrete of the block 4 is hardened, the formwork is disassembled, sleepers 22 (see FIG. 7) are installed on the block 4, and the anchor 21 is temporarily removed from the stigma 3 and the bracket 80. Then, as shown in FIG. 7, the rail 20 is moved forward to the top of the block 4, the front end of the rail 20 is aligned with the front end of the block 4, and then the rail 20 is moved to the stigma 3 and the block by the anchor 21. Fix to 4.

(6) Advance of the work vehicle Next, as shown in FIG. 8, after the anchor 36 is once removed from the stigma 3 and the bracket 80, the work vehicle 30 is moved forward to the top of the block 4 by the anchor 36. The work vehicle 30 is fixed to the stigma 3 and the block 4. At this time, the sliding body 34 on the front side is positioned at the front end of the rail 20, and the node on the upper front side of the main structure 31 and the front cross beam 32 are positioned forward from the block 4.

(7) Retreat of the cross beam of the extension jig Next, as shown in FIG. 9, by contracting the hydraulic jack 46, the cross beams 42 and 43 of the extension jig 40 are positioned at the cross beams 32 and 33 of the work vehicle 30, respectively. The cross beams 42 and 43 of the extension jig 40 are retracted until they are aligned. Then, a part of the work stand 50 and the formwork cradle 60 enters under the block 4.

(8) Suspension replacement of work pedestal and formwork receiving beam Next, the suspension members 38 and 39 are hung from the cross beams 32 and 33 of the work vehicle 30, and the lower ends of the suspension members 38 and 39 are fixed to the work gantry 50. To do. Then, the hanging members 48 and 49 are removed from the work stand 50. As a result, the work stand 50 is suspended from the cross beams 42 and 43 of the extension jig 40 to the cross beams 32 and 33 of the work vehicle 30.

Further, by suspending the formwork cradle 60 from the cross beams 32 and 33 of the work vehicle 30 by the chain block, the formwork cradle 60 is extended from the cross beams 42 and 43 of the extension jig 40 to the cross beams 32 and 33 of the work vehicle 30. Suspended to.

(9) Removal of extension jig and removal of bracket Next, as shown in FIG. 10, the extension jig 40 is removed from the work vehicle 30, and the bracket 80 is removed from the stigma 3. The extension jig 40 could be removed from the work vehicle 30 by suspending the work stand 50 and the formwork cradle 60 from the cross beams 42 and 43 of the extension jig 40 to the cross beams 32 and 33 of the work vehicle 30. This is because of the fact.

(10) Construction of Block Next, the formwork is assembled on the formwork cradle 60, reinforcing bars are arranged, and concrete is placed in the formwork. As a result, as shown in FIG. 11, the block 5 is constructed on the front side of the block 4, and the blocks 4 and 5 are integrated. As a result, the bridge girder is extended forward by the amount of the block 5 in the bridge axial direction.

(11) Advance of Rail and Work Vehicle Next, as shown in FIG. 12, after moving the rail 20 forward until the entire rail 20 rests on the stigma 3 and blocks 4 and 5, the rail 20 is shown in FIG. The work vehicle 30 is moved forward to the top of the block 5 as described above.

(12) Assembling the work vehicle on the opposite side and attaching the extension jig Next, as shown in FIG. 14, the work vehicle 30A, which is the same as the work vehicle 30, is placed on the rail 20 so as to face the work vehicle 30 in the opposite direction. After assembling on the rear side of the work vehicle 30, the extension jig 40 is assembled on the work vehicle 30A. Then, the same work pedestal 50A as the work pedestal 50 is suspended from the cross beams 42, 43 of the extension jig 40, and the same formwork cradle 60A as the formwork cradle 60 is hung from the cross beams 42, 43 of the extension jig 40. Suspended from. Further, the same framework scaffold 70A as the framework scaffold 70 is installed on the work stand 50A.

(13) Construction of the block on the opposite side After that, the block 4A and the block 5A are sequentially constructed in the same manner as the block 4 and the block 5 are constructed. When the work vehicle 30A is advanced on the blocks 4A and 5A, the extension rail is installed on the blocks 4A and 5A.

(14) Stretching and Construction of Bridge Girder After that, the blocks are sequentially constructed at the tip of the block 5 and the blocks are sequentially constructed at the tip of the block 5A in the same manner as when the block 5 is constructed. In this way, the bridge girder is extended and constructed so as to sequentially project in the direction of the bridge axis.

<3. Effect>
(A) As shown in FIG. 5, in the extended state of the hydraulic jack 46, the cross beams 42 and 43 of the extension jig 40 are located on the front side in the bridge axial direction with respect to the cross beams 32 and 33 of the work vehicle 30. Then, the work stand 50 and the formwork cradle 60 suspended from the cross beams 42 and 43 do not come into contact with the pier 2. Therefore, the work pedestal 50 does not tilt, and the block 4 (see FIG. 6) can be constructed on the front side of the stigma 3 in the bridge axis direction by working on the work pedestal 50.

(B) As shown in FIG. 9, when the hydraulic jack 46 is contracted, the cross beams 42 and 43 of the extension jig 40 are aligned with the cross beams 32 and 33 of the work vehicle 30, respectively. At this time, since a part of the work pedestal 50 and the formwork cradle 60 is under the block 4, work is performed on the work pedestal 50, and the block 5 is on the front side of the block 4 in the bridge axis direction (see FIG. 11). Can be built.

(C) As shown in FIG. 9, when the hydraulic jack 46 is contracted, the cross beams 42 and 43 of the extension jig 40 are aligned with the cross beams 32 and 33 of the work vehicle 30, respectively. Then, the work stand 50 can be suspended from the cross beams 42 and 43 to the cross beams 32 and 33. Further, since the suspension members 48 and 49 used before the suspension change are aligned with the suspension members 38 and 39 used after the suspension change in the bridge axis direction, the work stand 50 is suspended and replaced. However, the work stand 50 is stable.

(D) As shown in FIG. 5, since the rail 20 and the work vehicle 30 are fixed to the bracket 80 by the anchors 21 and 36, the work vehicle 30, the extension jig 40, the work stand 50, the formwork cradle 60 and The formwork scaffold 70 is stable.

(E) Since the extension jig 40 is removable from the work vehicle 30, the extension jig 40 can also be used for another work vehicle (for example, the work vehicle 30A).

<4. Modification example>
Although the embodiment for carrying out the present invention has been described above, the above-described embodiment is for facilitating the understanding of the present invention, and is not for limiting the interpretation of the present invention. Further, the present invention can be modified or improved without departing from the spirit thereof, and the present invention also includes an equivalent thereof. The changes from the above embodiments will be described below. The changes described below may be applied in combination as much as possible.

(A) An abutment may be constructed instead of the pier 2, and a stigma 3 may be constructed on the abutment. Then, as described above, the blocks 4 and 5 are constructed using the working device 10. In this case, the work vehicle 30A is not installed on the stigma 3, and the blocks 4A and 5A are not constructed.

(B) In the above embodiment, after the cross beams 42, 43 of the extension jig 40 are retracted to the positions of the cross beams 32, 33 of the work vehicle 30, the work stand 50 is operated from the cross beams 42, 43 of the extension jig 40. It was hung on the cross beams 32 and 33 of the car 30, and then the extension jig 40 was removed. On the other hand, the block 5 and the subsequent blocks may be constructed without removing the extension jig 40 while maintaining the state in which the work stand 50 is suspended from the cross beams 42 and 43 of the extension jig 40. In this case, the same extension jig as the extension jig 40 is attached to the work vehicle 30A to construct the blocks 4A and 5A.

(C) In the above embodiment, the formwork cradle 60 is suspended from the cross beams 42, 43 of the extension jig 40 and the cross beams 32, 33 of the work vehicle 30, but the formwork cradle 60 is installed on the work pedestal 50. You may.

2 ... Pier, 3 ... Capital (existing part of bridge girder), 4, 5, 4A, 5A ... Block (existing part of bridge girder), 10 ... Work equipment, 20 ... Rail, 30 ... Work vehicle, 31 ... Main structure, 32 ... 1st front cross beam (first cross beam), 33 ... 1st rear cross beam, 38, 39 ... hanging material, 40 ... extension jig, 41 ... vertical beam, 42 ... second front cross beam (second) Cross beam), 43 ... Second rear cross beam, 44 ... Front traveling body, 45 ... Rear traveling body, 48, 49 ... Suspended material

Claims (7)

A work device used in the overhanging erection method that extends the bridge girder in the direction of the bridge axis.
A work platform that is supported on the existing portion of the bridge girder and projects from the existing portion to the extension side in the bridge axis direction.
The first cross beam extending in the width direction of the bridge and provided on the portion of the work platform overhanging from the existing portion,
The extension jig installed on the first cross beam and
A work stand suspended from the extension jig is provided.
The extension jig
A vertical beam extending in the bridge axis direction, provided on the first cross beam, and projecting from the first cross beam to the extension side in the bridge axis direction.
A second cross beam guided by the vertical beam in the direction of the bridge axis, extending in the direction of the bridge width, and supporting the work pedestal in a suspended state.
A working apparatus comprising: a drive unit for moving the second cross beam between a position on the extension side in the bridge axis direction with respect to the first cross beam and a position aligned with the first cross beam. The work apparatus according to claim 1, wherein the work pedestal can be suspended from the second cross beam to the first cross beam. The work device according to claim 2, wherein the extension jig is removable from the first cross beam. An overhanging erection method for extending a bridge girder using the work device according to any one of claims 1 to 3.
The stigma construction process of constructing the stigma as a part of the bridge girder on the pier or abutment,
The first cross beam is supported on the column head, the work vehicle is extended from the column head to the extension side in the bridge axis direction, and the first cross beam extends in the bridge width direction. Is provided on the portion of the work vehicle overhanging from the existing portion, the vertical beam is provided on the first cross beam so as to extend in the bridge axis direction, and the vertical beam is provided in the bridge axial direction rather than the first cross beam. The second cross beam is more than the first cross beam so as to project to the extension side and extend the second cross beam in the bridge width direction and guide the second cross beam in the bridge axial direction by the vertical beam. An assembly step of suspending the work frame from the second cross beam provided at a position on the extension side in the bridge axis direction.
A first block construction step of constructing a first block as a part of the bridge girder on the extension side of the stigma in the bridge axis direction and above the work platform.
A relocation step of extending the work vehicle from the first block to the extension side in the bridge axis direction by moving the work vehicle from the stigma onto the first block.
A retreat step of moving the second cross beam to a position aligned with the first cross beam by the drive unit, and
An overhanging erection method comprising a second block construction step of constructing a second block as a part of the bridge girder on the extension side of the first block in the bridge axis direction and above the work pedestal. .. The step of installing the bracket on the opposite surface of the stigma on the extension side in the bridge axial direction is further included.
The overhanging erection method according to claim 4, wherein the work vehicle is supported on the bracket by an anchor in the assembly step. The overhanging erection method according to claim 4 or 5, further comprising a step of suspending the work pedestal from the second cross beam to the first cross beam after the retreating step. The overhanging erection method according to claim 6, further comprising a step of removing the extension jig from the first cross beam after the work pedestal is suspended and replaced.

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