Runaway prevention structure of floor slab cutting device and floor slab removing method

Abstract

To provide a runaway prevention structure of a floor slab cutting device and a floor slab removal method, which are less likely to cause a concrete cutter to run away or drop even when the upper surface of the floor slab to be cut has unevenness or a gradient and the clearance from the removed part of the floor slab is small.SOLUTION: A run-away prevention structure of a floor-slab cutting device that cuts a concrete floor slab in floor-slab replacement work is provided with a traveling plate 2 installed on a bridge girder (main-girder G1), a concrete cutter 3 that travels on the traveling plate 2 along the bridge girder (main-girder G1) to cut a concrete floor slab (intermediate-floor-slab C2), and a run-away prevention material 4 installed on the upper surface of the traveling plate 2 for hooking the traveling wheel 31 of the concrete cutter 3 so as not to run away from the cut end of the bridge girder (main girder G1).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a runaway prevention structure for a deck cutting device used in deck replacement work for PC composite girders, and a deck removal method using the same. [Background technology]

[0002] In previous deck renewal work (deck replacement work), the existing deck was cut and removed using cutting equipment such as a water jet (WJ), cutter, or wire saw, and then replaced with a cast-in-place concrete deck. However, when constructing a concrete deck using cast-in-place concrete, the construction period on site is long due to traffic restrictions, so shortening the on-site construction period was an issue.

[0003] In order to solve these problems, the applicant has developed a deck replacement method in which the existing main girder stirrups are cut and an anchoring steel pipe is crimped onto the tip, thereby maintaining the stirrup's functionality, and the stirrups are extended into the cutouts in the PC deck by crimping a steel pipe, thereby maintaining the necessary load-bearing capacity even when the main girder web sways.

[0004] Patent Document 1 discloses a method of replacing a concrete bridge with a precast deck slab, in which the upper part of the main girder that joins to the RC deck slab of the concrete bridge is chipped away to expose the upper part of a tensile resistance material such as a stirrup, the exposed tensile resistance material is cut partway and effectively fixed with mechanical fixing means to reduce the effective composition of the main girder, and then a precast deck slab is placed on top of the main girder with its effective composition reduced (see claim 1 in the scope of claims of Patent Document 1, paragraphs

[0025] to

[0044] of the specification, Figures 3 to 9 of the drawings, etc.).

[0005] Furthermore, Patent Document 2 discloses a method of replacing a concrete bridge with a precast deck, in which the upper part of the main girder that joins to the RC deck of a concrete bridge is chipped away to expose the upper part of a tensile resistance material such as a stirrup, the exposed tensile resistance material is cut partway and effectively fixed with mechanical fixing means, a shear stopper is connected to the mechanical fixing means, a precast deck with a box-cut hole is placed on top of the main girder, the shear stopper is accommodated in the box-cut hole, and a filler material is filled in and hardened, thereby integrating the precast deck and the main girder (see claim 1 of Patent Document 2, paragraphs

[0032] to

[0069] of the specification, Figures 3 to 9 of the drawings, etc.).

[0006] In the methods of replacing concrete bridges with precast decks as described in Patent Documents 1 and 2, it is necessary to remove the deck above the main girders with a water jet, and then cut off the intermediate deck and overhanging deck with a concrete cutter. However, in this process, the top surface of the deck over which the concrete cutter runs is very uneven because the area where the concrete has been removed with the water jet is exposed, and there is little clearance with the side that has already been removed, so there is a risk that the concrete cutter may run away or fall off depending on the direction of the cross gradient.

[0007] On the other hand, Patent Document 3 discloses a method for cutting and removing bridge joints, in which an auxiliary member is placed on the deck, one wheel of a concrete cutter is placed on it, the device is tilted, and the deck on both sides of the joint is cut diagonally to form multiple diagonal cutting grooves, and then the joint is cut at right angles to the diagonal cutting grooves, including the joint, and a crushing tool is inserted into the diagonal cutting grooves to remove the joint and deck (see claim 1 in the scope of claims of Patent Document 3, paragraphs

[0006] to

[0013] of the specification, figures 1 to 5 of the drawings, etc.).

[0008] However, the bridge joint cutting and removal method described in Patent Document 3 is merely an invention for cutting and removing deteriorated joints (expansion joints) of a bridge by running a concrete cutter over the deck as usual, and does not recognize the above-mentioned problems. For this reason, when applied to deck replacement work for PC composite girders, the bridge joint cutting and removal method described in Patent Document 3 is not able to prevent the concrete cutter from running away or falling off. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 6845456 [Patent Document 2] Patent No. 6845457 [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-60333 Summary of the Invention [Problem to be solved by the invention]

[0010] Therefore, the present invention was devised in consideration of the above-mentioned problems, and its purpose is to provide a runaway prevention structure for a slab cutting device and a slab removal method that can be applied to the above-mentioned method of replacing a precast slab, and that reduces the risk of the concrete cutter running away or falling off even when the top surface of the slab to be cut has unevenness or a slope and there is little clearance with the removed part of the slab. [Means for solving the problem]

[0011] The runaway prevention structure for a deck cutting device according to claim 1 is a runaway prevention structure for a deck cutting device that cuts concrete decks during deck replacement work, and is characterized by comprising a running plate installed on a bridge girder, a concrete cutter that runs on the running plate along the bridge girder to cut the concrete deck, and a runaway prevention material installed on the upper surface of the running plate that hooks the running wheels of the concrete cutter to prevent them from running away from the cut end of the bridge girder.

[0012] The runaway prevention structure for a deck cutting device according to claim 2 is characterized in that, in the runaway prevention structure for a deck cutting device according to claim 1, an inclined plate is installed on the upper surface of the running plate to provide a slope and cut the concrete deck diagonally.

[0013] The runaway prevention structure for a deck slab cutting device according to claim 3 is characterized in that, in the runaway prevention structure for a deck slab cutting device according to claim 1 or 2, the running plate is a checker plate having an anti-slip surface formed on the upper surface, and the runaway prevention material is an angle material.

[0014] The deck removal method of claim 4 is a deck removal method that uses the runaway prevention structure of the deck cutting device described in claim 1 to cut and remove the concrete deck, and is characterized in that it includes a joint concrete removal process in which the concrete portion of the joint between the bridge girder and the concrete deck is chipped off and removed with a water jet to expose part of the internal reinforcement of the bridge girder, followed by a running plate installation process in which the running plate is erected and covered on the top surface of the bridge girder from which the concrete portion has been removed in the joint concrete removal process, and a deck cutting and removal process in which the concrete cutter runs over the running plate installed in the running plate installation process to cut and remove the concrete deck.

[0015] The slab removal method of claim 5 is characterized in that, in the slab removal method of claim 4, an inclined plate is installed on the upper surface of the running plate to create a slope and cut the concrete slab diagonally, and in the slab cutting and removal process, the concrete cutter runs over the installed inclined plate to create a slope and cut the concrete slab diagonally for removal. [Effects of the Invention]

[0016] According to the inventions of claims 1 to 5, in the replacement or renewal work of the concrete deck slabs of PC composite girders with precast deck slabs, after the concrete portion at the joint between the bridge girder (main girder) and the concrete deck slab is chipped off and removed with a water jet, even if the clearance with the removed portion of the deck slab, such as an overhanging concrete deck slab, is small, the concrete deck slab, such as the intermediate deck slab, can be cut safely with a concrete cutter with little risk of running away or falling off. This significantly improves the work efficiency of the concrete deck cutting and removal work.

[0017] In particular, according to the inventions of claims 2 and 5, the concrete cutter runs over the installed inclined plate to create a slope, and then cuts and removes the concrete floor slab at an angle, which physically prevents the concrete floor slab from falling during cutting, eliminating the need for temporary facilities such as supports to prevent falling and achieving cost reduction. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a vertical cross-sectional view of a bridge to which a runaway prevention structure for a deck cutting device according to an embodiment of the present invention is applied. [Figure 2] Figure 2 shows an overview of the method of replacing concrete bridges with precast decks in Patent Documents 1 and 2, and a vertical cross-sectional view of the existing bridge showing the removed sections, where (a) shows the section where the concrete will be removed, and (b) shows the cutting positions of the concrete and rebar. [Figure 3]FIG. 3 is a partially enlarged perspective view showing the state in which the stirrup is extended in the method of replacing the concrete bridge with a precast deck slab, after the precast deck slab has been replaced. [Figure 4] FIG. 4 is a process explanatory diagram showing the temporary facility installation process of the deck slab removal method according to the embodiment of the present invention. [Figure 5] FIG. 5 is a process explanatory diagram showing the joint concrete removal process of the above-mentioned deck slab removal method. [Figure 6] FIG. 6 is a process explanatory diagram showing the overhanging deck removal process of the deck removal method. [Figure 7] FIG. 7 is a process explanatory diagram showing the running plate installation process of the deck slab removal method. [Figure 8] FIG. 8 is a process explanatory diagram showing the deck cutting and removal process of the deck removal method. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, an embodiment of a runaway prevention structure for a deck slab cutting device and a deck slab removal method according to the present invention will be described in detail with reference to the drawings.

[0020] <Structure to prevent deck cutting device from running away> First, a runaway prevention structure 1 for a deck slab cutting device according to an embodiment of the present invention will be described using Figure 1. Figure 1 is a vertical cross-sectional view of a bridge to which the runaway prevention structure 1 for a deck slab cutting device according to an embodiment of the present invention is applied. The description will be given by way of example of a case in which the intermediate deck slab C2, which is a concrete deck slab, is cut and removed after the cantilever deck C1 and wall parapet Wb of a bridge B1, which is an existing T-shaped bridge with T-girders, which are PC composite girders, as main girders G1, have been removed.

[0021] The runaway prevention structure 1 for a deck cutting device according to an embodiment of the present invention comprises a running plate 2 installed on the main girder G1, which is a bridge girder; a concrete cutter 3 that runs on this running plate 2 along the main girder G1 to cut the concrete deck (intermediate deck C2); and a runaway prevention material 4 installed on the upper surface of the running plate 2 that hooks onto the running wheels of this concrete cutter 3 to prevent them from running away from the cutting end of the main girder G1. This structure has the function of safely cutting with little risk of the concrete cutter 3 running away or falling off when cutting the intermediate deck C2 during deck replacement work on an existing bridge B1.

[0022] (Running board) The running plate 2 is a plate material based on a rectangular checker plate (checkered steel plate) 20 with anti-slip striped protrusions formed in a repeated pattern on the surface (top surface) of the steel plate, and as will be described later, has the function of covering and smoothing the uneven surface where aggregate and rebar are exposed after concrete has been chipped away with a water jet, thereby facilitating the travel of the concrete cutter 3. Of course, the checker plate 20 is not limited to a steel plate, and may be a metal plate such as a stainless steel plate or an aluminum steel plate, or an FRP plate.

[0023] A runaway prevention member 4 is attached to the upper surface of this running plate 2 to hook and stop the running wheels 31 of the concrete cutter 3 from running away from the cutting end on the protruding deck C1 side of the upper surface of the main girder G1.

[0024] In addition, an inclined plate 21 is attached to the upper surface of the running plate 2, so that the running wheels 31 of the concrete cutter 3 ride on it, causing the concrete cutter 3 to run at an angle and cut the concrete floor slab (intermediate floor slab C2) at an angle.

[0025] A pair of left and right anti-slip members 22 are attached to the underside of this checker plate 20 (running plate 2) to prevent the checker plate 20 from shifting horizontally on the top surface of the main girder G1. These anti-slip members 22 are made of L-shaped angle irons (equal leg angle irons) and are joined to the top surface of the checker plate 20 by welding or the like. Of course, the anti-slip members 22 are not limited to steel material, and may be any angle material made of metal or FRP.

[0026] (concrete cutter) The concrete cutter 3 is a hand-pushed or semi-self-propelled concrete cutter that is wet or dry and has a diamond blade 30 driven by an electric motor or engine, and has a plurality of running wheels 31 for travel.

[0027] (Escape prevention material) The runaway prevention material 4 is made of an L-shaped angle material such as an equal-leg angle iron, and is joined by welding or the like to the upper surface of the checker plate 20. Of course, the runaway prevention material 4 is not limited to steel material, and may be any angle material made of metal or FRP.

[0028] <Slab removal method> Next, a deck slab removal method according to an embodiment of the present invention will be described using Figures 2 to 8. Using the runaway prevention structure 1 for the deck slab cutting device described above, an example will be described in which a concrete deck slab portion is removed from an existing PC composite girder in deck slab replacement work to replace the deck portion of a bridge B1 consisting of an existing T-shaped bridge with a PC composite T-girder as the main girder G1 with a precast deck PC1. Note that the symbol C1 indicates the cantilever deck C1, and the symbols C2 and C3 indicate the intermediate deck C2 and intermediate deck C3. Furthermore, the symbol Wb indicates the wall parapet Wb.

[0029] First, using Figures 2 and 3, we will explain the outline and removed portion of the method for replacing a concrete bridge with a precast deck slab (hereinafter referred to as the SP clamp method) described in Patent Documents 1 and 2, which are mentioned in the background art to which this invention applies. Figure 2 is a vertical cross-sectional view of the existing bridge showing the outline and removed portion of the SP clamp method, where (a) shows the portion from which the concrete has been removed, and (b) shows the cutting positions of the concrete and rebar. Also, Figure 3 is a partially enlarged perspective view showing the state of the stirrup when extended in the SP clamp method, after it has been replaced with a precast deck slab.

[0030] The SP clamp method developed by the applicant is a deck replacement method for the existing decks (extending deck C1, intermediate deck C2, intermediate deck C3) of Bridge B1, a PC composite girder bridge, by removing the deteriorated cast-in-place concrete deck sections and replacing them with precast deck PC1 while maintaining the load-bearing capacity of the existing structure.

[0031] Specifically, in the SP clamp method, as shown in Figures 2(a) and 2(b), the overhanging deck C1 is cut and removed using a concrete cutter 3 or similar, and the stirrup Sr, which is part of the internal reinforcement of the existing main girder G1, is cut along the cutting line L1 shown by the dashed dotted line, and then the function of the stirrup Sr is maintained by crimping a mechanical anchor Mf to its tip, as shown in Figure 3. Furthermore, this SP clamp method extends the stirrup Sr by crimping a steel pipe Sp (steel pipe crimping) into the cutout part Np of the precast deck PC1, making it possible to maintain the necessary load-bearing performance even when the web of the main girder G1 swings.

[0032] Here, the symbol As in the figure denotes the shear-stop rebars that were installed later on the top surface of the main girder G1, and the cutting line L2 is the concrete removal line along which the concrete is removed using a water jet. Note that the cutting line L1 can also be cut with a wire saw or similar tool, since it cuts the internal reinforcing bars (rebars) along with the concrete.

[0033] The deck removal method according to this embodiment is a method of applying the SP clamp method to cut and remove the concrete deck portion from an existing PC composite girder using the runaway prevention structure 1 of the deck cutting device described above.

[0034] (Advance preparation) In the deck removal method according to this embodiment, as a preliminary step, a temporary concrete vehicle protection fence Pf is installed in the center of the road surface of the bridge B1 to separate the road bridge traffic lane from the traffic-restricted zone for the renewal work (see Figure 4). Then, the soundproof walls are removed, the asphalt pavement in the construction area is cut, and obstructive guardrails and the like are removed.

[0035] (Temporary facility installation process) Next, in the deck removal method according to this embodiment, a temporary facility installation process is carried out to install necessary temporary facilities around the bridge B1 where construction work is to be carried out, as shown in Fig. 4. Fig. 4 is a process explanatory diagram showing the temporary facility installation process of the deck removal method according to this embodiment.

[0036] Specifically, in this process, as shown in Figure 4, cantilever deck shoring Sh1 is installed under the cantilever deck C1 using temporary materials such as single pipes and bitie scaffolding to support the cantilever deck C1, which also serves as scaffolding, so that it does not fall, and intermediate deck shoring Sh2 is installed under the intermediate deck C3 using temporary materials such as square pipes and pipe supports to support the intermediate deck C3 so that it does not fall. Of course, it goes without saying that if there is no need to install the cantilever deck shoring Sh1, it does not have to be installed.

[0037] (Extended deck removal process) Next, in the slab removal method according to this embodiment, an overhanging slab removal process is carried out in which the overhanging slab C1 and the wall parapet Wb are cut and removed, as shown in Fig. 5. Fig. 5 is a process explanatory diagram showing the overhanging slab removal process of the slab removal method according to this embodiment.

[0038] Specifically, in this process, as shown in Figure 5, the overhanging deck C1 is cut approximately vertically using the aforementioned concrete cutter 3 or the like, and then lifted and transported using a crane or the like to remove the overhanging deck C1 and wall parapet Wb.

[0039] (Concrete joint removal process) Next, in the deck removal method according to this embodiment, a joint concrete removal process is carried out to remove concrete from the composite section SC, which is the joint between the main girder G1, a PC composite girder, and the concrete deck slab, from the top of the main girder G1, as shown in Figure 6. Figure 6 is a process explanatory diagram showing the joint concrete removal process of the deck removal method according to this embodiment.

[0040] Specifically, in this process, as shown in Figure 6, the concrete in the composite section SC is removed along the cutting line L2 using a water jet. As mentioned above, the stirrup Sr is stretched by crimping the steel pipe Sp and the mechanical anchor Mf is crimped to maintain the function of the stirrup Sr, so the rebar is left in place and only the concrete part is removed (see also Figure 2(b)). In this process, after the concrete part is removed with a water jet, it is preferable to remove the stirrup Sr and any unnecessary rebar by cutting and removing it.

[0041] (Running board installation process) Next, in the deck removal method according to this embodiment, a running plate installation step is carried out in which the running plate 2 is erected and installed in the recess R1 created by chipping away the composite section SC in the joint concrete removal step, as shown in Figure 7. Figure 7 is a process explanatory diagram showing the running plate installation step in the deck removal method according to this embodiment.

[0042] Specifically, in this process, as shown in Figure 7, a running plate 2 consisting of a rectangular checker plate 20 with anti-slip striped protrusions formed in a repeated pattern on the surface (top surface) of the steel plate is placed across and covers the recessed portion R1. This is to enable the concrete cutter 3 to run over the smooth, anti-slip checker plate 20, which is easy to run over, and cut the intermediate deck C2 (concrete deck), without having to run over the uneven surfaces where aggregate and rebar are exposed on the bottom and sides of the recessed portion R1 where the concrete has been chipped away with the water jet.

[0043] As mentioned above, the checker plate 20 of the running board 2 has an upper surface to which an anti-runaway member 4 and an inclined plate 21 are attached, and the checker plate 20 has a pair of left and right anti-slip members 22 attached to its lower surface.

[0044] (Floor slab cutting and removal process) Next, in the slab removal method according to this embodiment, a slab cutting and removal step is carried out in which the concrete slabs, intermediate slabs C2 and C3, are cut and removed by running on the running plate 2 installed in the running plate installation step described above with a concrete cutter 3, as shown in Figure 8. Figure 8 is a process explanatory diagram showing the slab cutting and removal step of the slab removal method according to this embodiment.

[0045] Specifically, in this process, as shown in Figure 8, the running wheels 31 travel on the inclined plate 21 attached to the upper surface of the checker plate 20 of the running board 2, and the diamond blade 30 of the concrete cutter 3 is tilted relative to the vertical plane to form a slope and cut the intermediate deck C2, shown by the shaded area, at an angle. This physically prevents the intermediate deck C2 from falling during cutting, and eliminates the need for temporary facilities to prevent it from falling, such as the cantilever deck shoring Sh1 and the intermediate deck shoring Sh2, below the intermediate deck C2, thereby achieving cost reductions.

[0046] Also, as mentioned above, a pair of left and right anti-slip materials 22 are attached to the underside of the checker plate 20, so there is little risk that the checker plate 20 of the running plate 2 will slip out of the recess R1 and fall off when the concrete cutter 3 is running, and the cutting work of the intermediate deck C2 can be carried out safely.

[0047] Furthermore, in this process, as shown in Figure 8, runaway prevention materials 4 are attached to the upper surfaces of the checker plates 20 of the running board 2, so there is little risk of the concrete cutter 3 running away or falling off even if there is a small clearance between the part where the deck slab, such as the overhanging deck slab C1, has been removed and the edge of the checker plate 20. Therefore, in the deck slab removal method according to this embodiment, the concrete cutter 3 can safely cut the intermediate deck slab C2, significantly improving the work efficiency of this process.

[0048] In this process, as shown in Figure 8, similar to the intermediate deck C2, the running wheels 31 run over the checker plates 20 of the running board 2, and the concrete cutter 3 cuts and removes the intermediate deck C3, which is the concrete deck indicated by the shaded area. However, because the aforementioned intermediate deck support Sh2 is installed below the intermediate deck C3 to prevent the edge of the intermediate deck on the traffic lane side from dropping, unlike the intermediate deck C2, there is no need to cut diagonally with the diamond blade 30 inclined relative to the vertical plane. Furthermore, if the intermediate deck C3 is not cut and removed before the intermediate deck C2, there is no problem of a small clearance between the removed part and the edge of the checker plates 20, and therefore there is no need to install runaway prevention material 4.

[0049] Completion of this process marks the end of the deck removal work for removing the concrete deck portion from the existing PC composite girder using the deck removal method according to this embodiment. Then, using the SP clamp method, as shown in Figure 3, steel pipes Sp are crimped and extended onto the stirrups Sr exposed from the top of the main girder G1, mechanical anchors Mf are joined, and the precast deck PC1 is erected. Next, non-shrinkage mortar is filled between the precast deck PC1 and the main girder G1, and concrete is poured into the cutouts Np of the precast deck PC1 and into the joints (not shown) between the precast deck PC1. This completes the deck replacement work, in which the deteriorated cast-in-place concrete deck portion is removed and replaced with the precast deck PC1.

[0050] According to the runaway prevention structure 1 for the deck slab cutting device and the deck slab removal method using the same according to the embodiment of the present invention described above, the runaway prevention material 4 is attached to the upper surface of the checker plate 20 of the running plate 2, so there is little risk of the concrete cutter 3 running away or falling off even if there is a small clearance between the part where the overhanging deck C1 of the main girder G1 has been removed and the edge of the checker plate 20. Therefore, with the deck slab removal method according to this embodiment, the concrete cutter 3 can safely cut the intermediate deck C2, significantly improving the work efficiency of the concrete deck cutting work with the concrete cutter 3.

[0051] Furthermore, according to the deck cutting device's runaway prevention structure 1 and deck removal method, the concrete cutter 3 travels on the inclined plate 21 using the running wheels 31, and the diamond blade 30 of the concrete cutter 3 is tilted and inclined relative to the vertical plane to cut the intermediate deck C2, shown by the shaded area, at an angle, thereby physically preventing the intermediate deck C2 from falling during cutting. This eliminates the need for temporary facilities to prevent falling, such as the cantilever deck support Sh1 and the intermediate deck support Sh2, under the intermediate deck C2, and reduces costs by reducing the number of temporary facilities.

[0052] Of course, it is also possible to install temporary facilities to prevent falling, such as support structures Sh1 for the protruding deck and support structures Sh2 for the intermediate deck, under the intermediate decks C2 and C3 without installing the inclined plate 21, and cut the intermediate decks C2 and C3 in a vertical plane with the diamond blade 30 of the concrete cutter 3.

[0053] The runaway prevention structure 1 for a deck cutting device according to an embodiment of the present invention and the deck removal method using the same have been described in detail above. However, the above-described and illustrated embodiments are merely specific embodiments for carrying out the present invention. Therefore, the technical scope of the present invention should not be interpreted as being limited by these embodiments.

[0054] In particular, the runaway prevention structure 1 for the deck cutting device according to the embodiment of the present invention and the deck removal method using the same have been described using an example in which the bridge B1 is constructed half-section at a time, but it is also possible to remove the deck of the entire section of the bridge B1 at once and omit temporary facilities for preventing falls, such as the intermediate deck support structure Sh2. [Explanation of symbols]

[0055] 1: Structure to prevent deck cutting device from running away 2: Running board 20: Checker plate 21: Inclined plate 22: Anti-slip material 3: Concrete cutter (floor slab cutting device) 30: Diamond Blade 31: Running wheels 4:Escape prevention material B1: Bridge G1: Main girder (bridge girder) Sr: Stirrup Sp: Steel pipe Mf: Mechanical fixing body SC: Synthesis part R1: Recess C1: Cantilevered deck (concrete deck) C2: Intermediate floor slab (concrete floor slab) C3: Intermediate floor slab (concrete floor slab) Wb: Wall parapet Pf: Temporary protective fence (temporary facility) Sh1: Support for cantilever deck (temporary facility) Sh2: Intermediate deck support (temporary facility) PC1: Precast deck Np: Notch

Claims

1. A runaway prevention structure for a deck cutting device that cuts a concrete deck during deck replacement work, The concrete cutter is equipped with a running plate installed on the bridge girder, a concrete cutter that runs on the running plate along the bridge girder to cut the concrete floor slab, and a runaway prevention member installed on the upper surface of the running plate to hook the running wheels of the concrete cutter so that they do not run away from the cut end of the bridge girder. A structure for preventing runaway of a deck cutting device, characterized by the above.

2. An inclined plate is installed on the upper surface of the running plate to cut the concrete floor slab diagonally.

2. The runaway prevention structure for a deck cutting device according to claim 1.

3. The running plate is a checker plate with a non-slip surface formed on the top surface, and the runaway prevention material is an angle material.

3. A runaway prevention structure for a deck cutting device according to claim 1 or 2.

4. A slab removal method for cutting and removing the concrete slab using the runaway prevention structure of the slab cutting device according to claim 1, After performing a joint concrete removal process in which the concrete portion of the joint between the bridge girder and the concrete deck is chipped off and removed with a water jet to expose a portion of the internal reinforcement of the bridge girder, a running plate installation process of erecting and covering the running plate on the upper surface of the bridge girder from which the concrete portion has been removed in the joint concrete removal process; and a slab cutting and removal step of running the concrete cutter over the running plate installed in the running plate installation step to cut and remove the concrete slab. A deck removal method characterized by the following.

5. An inclined plate is installed on the upper surface of the running plate to provide a slope and cut the concrete floor slab diagonally, In the deck cutting and removal process, the concrete cutter runs on the installed inclined plate to create a slope, and the concrete deck is cut diagonally and removed. The deck slab removal method according to claim 4, characterized in that

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