JP6715230B2 - Method of removing slab of composite girder bridge and reinforcing member used for it - Google Patents

Description

The present invention relates to a method for removing a floor slab of a synthetic girder bridge and a reinforcing member used for the method, and in particular, while the road is in service, the concrete in the floor slab haunch part is previously removed with a water jet, and sequentially reinforced, so that the road is closed. The present invention relates to a method for removing a floor slab of a composite girder bridge and a reinforcing member used for the method, which significantly shortens the subsequent work period.

Viaducts for roads are being used all over Japan, including highways developed by making extensive use of viaducts. Many of them have deteriorated over a long period of use and require repair or replacement.
When replacing a bridge, it is possible to build a new bridge adjacent to an existing bridge while securing traffic on the existing bridge and switch to the bridge when it is completed. Such a method is not practical for roads with continuous viaducts. Therefore, the method of replacing the floor slab is adopted while leaving the existing bridge girder.

However, since the floor slab is a large heavy structure, it is not easy to remove the floor slab, and a method of cutting the floor slab and removing it is usually performed. In addition, in the case of a composite girder bridge in which the bridge girder and floor slab are integrally fixed during construction, it is firmly fixed to the bridge girder, and it is troublesome to cut and remove the fixing part with the bridge girder. It is working.
In such synthetic girder bridges, the floor slabs except the part directly above the bridge girders are removed by cutting them into blocks, and the remaining part immediately above the bridge girders is mechanically suspended to remove concrete. There are various restrictions such as the size of the floor slab to be used, the long cutting distance required to remove the slab because it is necessary to cut both sides of the bridge girder along the bridge girder, and noise from chipping. There were challenges.

On the other hand, there has been proposed a technique for efficiently separating the fixed portion between the floor slab and the bridge girder in consideration of reuse of the bridge girder.
In Patent Document 1, from the upper surface of the floor slab, only the concrete is removed by a high-pressure water jet along the length direction of the steel main girder to form a cutting zone having a width narrower than the width of the steel girder, and cutting is performed. The girder on the steel girder upper surface in the zone and part of the reinforcing bars embedded in the concrete floor slab are exposed to perform edge cutting between the steel girder and the concrete floor slab, and the concrete floor slab is cut into block pieces of the required size It describes the method of removing the bridge deck that is to be peeled off and removed.

According to this removal method, the part fixed to the bridge girder can be easily separated by removing the concrete by the water jet, so there is no need to cut both sides of the bridge girder along the bridge girder, and the removal work efficiency Expected to improve.
However, whether this removal method or the conventional method is used, it is necessary to stop the passage of vehicles and the like at the stage of starting the removal of the floor slab. The key points of transportation and viaducts on expressways are a part of the aorta of logistics, and even if the floor slabs are replaced, closing the road for a long time will cause a large economic loss, and the construction period to close the road as much as possible It is required to be short.

In Patent Document 2, a haunch part at a contact portion between a concrete floor slab and a bridge girder and a floor slab fixing anchor are horizontally cut by applying a sawing wire, a disk-shaped blade, a water jet, etc. to a cutting location, The method of removing the bridge slab is characterized by separating the bridge girder from the bridge girder.The cutting of the haunch part at the contact part between the concrete slab and the bridge girder is for the horizontal direction, so do not stop the traffic. It is also stated that it is possible.
However, since the haunch portion is horizontally cut and separated, the effect of the slippage is lost, and it is a safety issue to allow the vehicle or the like to pass in this state.
Therefore, there is a need for a method of removing the floor slab of a composite girder bridge that can advance the process that can be performed before the road is closed and can significantly reduce the work period after the road is closed.

JP 2012-207388 A Japanese Patent Publication No. 06-043682

The present invention has been made in view of the problems in the method of removing the floor slab of the conventional composite girder bridge, and the object of the present invention is to water-jet the concrete of the floor slab haunch portion in advance while the road is in service. It is intended to provide a method of removing a floor slab of a synthetic girder bridge and a reinforcing member used for the method, in which the work period after suspension of traffic is significantly shortened by removing the slab and sequentially reinforcing it.

The method of removing the floor slab of the composite girder bridge according to the present invention made to achieve the above object is to leave a slip-stop line from the side of the floor slab while maintaining the upper surface of the floor slab so as not to hinder the passage of vehicles. Floor slab Removing concrete around the detent bar with a water jet in a specified section, installing and fixing a reinforcing member around a specific detent bar in the section where the concrete was removed, and floor slab After stopping the upper traffic, there is a step of removing the reinforcing member and cutting the anti-slip bar to remove the floor slab, a step of removing the concrete in a predetermined section and a step of installing and fixing the reinforcing member. Is repeated while changing the section, and the concrete of the floor slab haunch part in the section where the floor slab is removed is characterized.

In the step of removing the concrete in the floor slab haunch portion with a water jet in a predetermined section, the water jet nozzle is reciprocally moved in the bridge axis direction to shift one side of the floor girder portion of the composite girder bridge to prevent slippage in the first row. And removing concrete until the water jet is visible, and moving the nozzle of the water jet in the direction perpendicular to the bridge axis between the adjacent detent bars to remove concrete until reaching the other side of the composite girder bridge deck haunch. It is preferable to include a step and a step of exchanging the nozzle with a nozzle which ejects in a direction perpendicular to the extending direction and cutting and removing concrete between the anti-shift bars arranged in the direction perpendicular to the bridge axis.

The step of installing the reinforcing member includes the steps of installing a plurality of back blocks having recesses facing the back surface of the anti-shift bar so that the recesses face the back surface of the anti-shift bar, and inserting the girder flange of the bridge girder. Install the main body block on the girder flange with a plurality of recesses for enclosing the anti-slip bars corresponding to the groove and the recess of the back block, and install multiple back surfaces so that each recess of the main block encloses the anti-slip bar. It is preferable to include a step of combining with the block and a step of injecting mortar into a space surrounding the anti-slip bar to fix the anti-slip bar and the reinforcing member.

The steps of removing the reinforcing member and cutting the anti-slip bar to remove the floor slab include the steps of removing the reinforcing member, cutting the floor slab into blocks, and preventing slippage necessary for fixing the floor slab block. It is preferable to include a step of cutting the anti-slip bars other than the streaks, and a step of unloading the floor slab by cutting the remaining anti-slip muscles with the floor slab suspended.

The reinforcing member according to the present invention made to achieve the above object is a reinforcing member used to reinforce the section where the concrete is removed when the floor slab of the composite girder bridge is removed, and for sandwiching the girder flange of the bridge girder. Of the main body block including a groove portion of the main body block, a plurality of recesses for enclosing the anti-slip bar, and an injection hole for injecting mortar into the recess, and enclosing the anti-slip bar of the main block. And a plurality of back blocks for forming a space to be embedded therein.

According to the method of removing a floor slab of a composite girder bridge according to the present invention, with the upper surface of the floor slab being maintained, the concrete is removed by cutting at certain intervals from the side of the floor slab haunch portion and the reinforcement member is installed. By repeating the above steps, the concrete on the haunch part of the required section can be removed, so there is no need to block vehicles, etc. during this period, and as a result of this preliminary work, the construction period in which vehicles, etc. must be blocked is greatly shortened. can do.
Further, according to the method of removing the floor slab of the composite girder bridge according to the present invention, it is not necessary to cut both sides of the bridge girder along the bridge girder, and it is possible to increase the size of the floor slab block to be cut and cut. Therefore, the total cutting distance of the floor slab by the road cutter is short, and the construction period can be shortened.

According to the method of removing a floor slab of a composite girder bridge according to the present invention, since the reinforcing member is fixed to the anti-slip bar by the mortar, the bending stress generated in the anti-slip bar by removing the concrete around the anti-slip bar. Even after removing the concrete around the anti-slip bar, it is possible to ensure safety when the vehicle is passing.
Furthermore, since the reinforcing member according to the present invention is composed of a plurality of blocks, is easy to assemble and disassemble, and can be reused, it is possible to prevent an unnecessary increase in the cost for removing the deck slab of the synthetic girder bridge. ..

It is a figure which shows roughly the structure of the synthetic girder bridge before applying the removal method of the floor slab of the synthetic girder bridge by the embodiment of the present invention. It is a figure for demonstrating the method of removing the concrete of the floor slab part with a water jet by the embodiment of this invention. FIG. 5 is a diagram showing a reinforcing member according to an embodiment of the present invention. FIG. 6 is a view for explaining a method of installing the reinforcing member according to the embodiment of the present invention. 6 is a flowchart illustrating a method of removing a floor slab of a synthetic girder bridge according to an exemplary embodiment of the present invention. 6 is a flowchart illustrating a method of removing concrete on a floor slab haunch according to an embodiment of the present invention with a water jet. 6 is a flowchart illustrating a method of installing a reinforcing member according to an exemplary embodiment of the present invention.

Next, a specific example of a mode for carrying out the method of removing a deck of a composite girder bridge according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram schematically showing the structure of a composite girder bridge before applying the method of removing a deck of a composite girder bridge according to an embodiment of the present invention.

Referring to FIG. 1, a composite girder bridge 1 includes a steel bridge girder 2, a floor slab 3, a floor slab haunch part 4 having a side surface which rises from the steel bridge girder 2 to the floor slab 3 while inclining and rising, and on the steel bridge girder 2. A plurality of shift-stop bars 5 arranged in a matrix and welded to each other. When arranged closely, the anti-slip bars 5 are generally installed at intervals of about 100 mm both in the bridge axis direction and in the direction perpendicular to the bridge axis.
In the composite girder bridge 1, the steel bridge girder 2 and the floor slab 3 are integrated by placing concrete so that the floor slab 3 installed on the steel bridge girder 2 also partially plays the role of the bridge girder. At this time, the anti-slip bar 5 arranged on the steel bridge girder 2 functions to increase the joint strength between the steel bridge girder 2 and the floor slab 3.

On the other hand, when the bridge is used for a long time, the floor slab part deteriorates. However, in the case of the composite girder bridge, the steel bridge girder 2 and the floor slab 3 are firmly joined by the anti-slip bar 5, so that there is a problem that the floor slab 3 cannot be easily replaced. For this reason, replacement of the floor slab 3 takes a long period of time, and the work is generally performed after the passage of vehicles and the like is stopped, and it is an important issue that the passage has a great social impact.

The method of removing the floor slab of the composite girder bridge according to the embodiment of the present invention is based on these problems of the composite girder bridge, and by removing concrete around the slip-stop bar 5 and temporarily reinforcing it with a reinforcing member that can be easily removed, Without stopping the passage, the concrete around the anti-slip bar 5 in the section where the floor slab 3 needs to be replaced is removed, and the process is advanced until the floor slab 3 becomes easy to remove. By proceeding with the preparatory work in this way, the work of removing the floor slab 3 after the passage of the vehicle is stopped becomes easier, and the construction period is shortened. As a result, the period of the vehicle passage can be shortened and the social impact is reduced. You can

Hereinafter, a method for removing concrete around the anti-shift bar 5 will be described with reference to FIG.
FIG. 2 is a diagram for explaining a method of removing concrete of the floor slab haunch part 4 with a water jet according to the embodiment of the present invention.
Referring to FIG. 2, a method of removing concrete in three stages (a) to (c) is shown. For the sake of clarity, the position where the concrete is removed is shown in a plan view, and the floor slab extending above it is omitted. Is shown.
When an attempt is made to cut an inclined surface such as the side surface of the floor slab haunch part 4 with a water jet, the injected water is reflected obliquely and the water pressure that contributes to cutting is dispersed, so cutting does not proceed efficiently. .. Therefore, the side surface of the floor slab haunch part 4 to be cut is mechanically suspended in advance so as to be a vertical surface.

A water jet device 10 is installed along the steel bridge girder 2 in order to remove concrete from the floor slab haunch portion 4. In removing the floor slab 3 of the composite girder bridge 1, a scaffold for performing work is installed. In the embodiment, a suspension scaffold is installed, and the water jet device 10 is installed on the suspension scaffold. In order to prevent the water used in the water jet device 10 from falling under the suspended scaffolding, the suspended scaffolding is waterproofed, and a dedicated drainage port is provided in the suspended scaffolding to collect water containing concrete powder by cutting. ..

The water jet device 10 includes a traveling base 11 for moving a nozzle of a water jet in the bridge axis direction, a bridge axial direction moving base 12 movably mounted on the traveling base 11 along the traveling base 11, and a bridge shaft. Right-angled pedestal 13 which is mounted on the direction-moving base 12 so as to extend in the direction perpendicular to the bridge axis, and right-angled movement which is movably mounted on the right-angled pedestal 13 along the right-angled pedestal 13 It includes a water jet nozzle that is mounted on the platform 14 and the orthogonal movement platform 14 so as to extend in a direction perpendicular to the bridge axis.

The nozzle of the water jet can be moved in the bridge axis direction and the direction perpendicular to the bridge axis by the bridge axis direction moving table 12 and the right angle direction moving table 14. The nozzle of the water jet can freely move on a plane corresponding to the movable areas of the bridge axis direction moving table 12 and the right angle direction moving table 14 by a control device (not shown). Further, as described below, the nozzle of the water jet can be selectively used by changing nozzles having different shapes in relation to the position where concrete is cut.

Referring to FIG. 2( a ), the water jet nozzle is reciprocally moved in the bridge axis direction to cut one side of the floor girder portion 4 of the composite girder bridge 1 until the first row of the detent bars 5 is visible to cut concrete. To do. In this case, the water jet nozzle uses a front jet nozzle 15 that jets a water jet in the nozzle extending direction. In the embodiment, the front jet nozzle 15 is configured to jet high-pressure water of about 200 MPa while rotating it at an angle of 5° to 9° with respect to the central axis of the front jet nozzle 15 in the extending direction. ..

The step of cutting and removing the concrete of the floor slab haunch part 4 is performed as a preparatory step for removal of the floor slab 3, but in order to carry out the passage of vehicles passing over the floor slab 3 without stopping, a long section at a time If the concrete of the floor slab haunch portion 4 is removed over the entire length, there is a possibility that a problem in strength may occur. Therefore, in the embodiment, a predetermined section is set, the concrete of the floor slab haunch portion 4 is removed for each predetermined section, and the removed portion is temporarily reinforced by a reinforcing member. The setting of the predetermined section is based on the structural analysis, and even if the concrete of the floor slab 4 is removed, the limit section range that does not hinder the passage of vehicles on the floor slab 3 is obtained, and the limit section range is not exceeded. Make settings.

Since the reinforcing member is attached to the steel bridge girder 2 as described later, the position for removing the concrete of the floor slab haunch part 4 is adjusted so as to include the portion directly above the steel bridge girder 2. Since the floor slab haunch part 4 spreads laterally as it moves upward from the upper surface of the steel bridge girder 2 and the amount of concrete to be cut increases, the concrete in the part close to the upper surface of the steel bridge girder 2 is also increased in terms of work efficiency. It is preferable to set to remove.

After cutting and removing the concrete until the first row of the detent bars 5 in the predetermined section can be seen, as shown in FIG. 2(b), the nozzle of the water jet is inserted between the adjacent detent bars 5 in the direction perpendicular to the bridge axis. Then, the concrete is cut and removed to reach the other side of the floor slab 4 of the composite girder bridge 1.
The water jet nozzle used at this time is also the front injection nozzle 15 as in FIG.

When the concrete cutting in the direction perpendicular to the bridge axis progresses and reaches the other side of the floor slab haunch part 4, the water jet is released into the air with the same force, so the water jet is cut before cutting in the direction perpendicular to the bridge axis. The other side of the deck slab 4 of the composite girder bridge 1 is a drainage means that integrates a weir wall that prevents discharge into the air even if it penetrates concrete and a drain gutter that collects and drains the dammed water. To install. The drainage means that integrates the dam wall and the drain gutter also plays a role of reducing the noise that cuts the air generated when the water jet is discharged into the air.

After cutting and removing the concrete between the detent bars 5 adjacent to the bridge axis direction, the concrete remains between the detent bars 5 aligned in the direction perpendicular to the bridge axis, and the concrete becomes a wall shape in the direction perpendicular to the bridge axis. It will remain. It is difficult to cut this portion because the front jet nozzle 15 cannot hit a water jet having a sufficiently high pressure.

Therefore, in the next stage, as shown in FIG. 2(c), the front injection nozzle 15 is replaced with a side injection nozzle 16 that ejects a water jet in a direction perpendicular to the stretching direction, and the misalignment is arranged in a direction perpendicular to the bridge axis. The concrete between the retaining bars 5 is removed by cutting.
Also in this case, the concrete between the anti-shift bars 5 is removed by cutting while moving the side injection nozzle 16 in the direction perpendicular to the bridge axis.

As described above, by going through the three steps of FIGS. 2A to 2C, it is possible to remove the concrete around the anti-slip bar 5 in the predetermined section. By cutting and removing concrete with a water jet, it is possible to remove concrete with less noise and without scattering dust as compared with the removal by mechanical chipping which is performed by a conventional method.
After removing the concrete around the anti-slip bar 5 in a predetermined section of a predetermined section, temporary reinforcement is immediately performed by a reinforcing member.

FIG. 3 is a diagram showing a reinforcing member according to an embodiment of the present invention. 3A is a plan view of the reinforcing member 20, and FIG. 3B is a sectional view taken along the line AA shown in FIG.
Referring to FIG. 3, the reinforcing member 20 includes a main body block 21 and two back blocks (31, 32) as main components.

The main body block 21 has a plurality of recesses 22 for enclosing the anti-slip bar 5, a groove 23 for sandwiching the girder flange of the steel bridge girder 2, and a fixing for fixing the main body block 21 to the girder flange of the steel bridge girder 2. A fixing screw hole 24 for mounting a screw and an injection hole 25 for injecting mortar into each recess 22 are provided. Further, the main body block 21 is provided with a fixing screw insertion hole 28 for connecting with the back block because it is used in combination with the back block (31, 32).

The reinforcing member 20 is for temporarily reinforcing the anti-slip bar 5 during the preparatory work performed without removing the passage of the vehicle in the work of removing the floor slab 3, and after the passage of the vehicle is stopped. Since the floor slab 3 is to be removed first, it is required that it can be easily removed.
Therefore, the main body block 21 is provided with a taper portion 26 on the upper surface for easy removal, and a screw hole 27 for the push-out bolt for tightening the push-out bolt so that the mortar injected into the recess 22 and hardened is used as a reaction material. Prepare In another embodiment, a screw hole 27 for an extrusion bolt may be provided at a position corresponding to the groove 23 so that the girder flange end of the steel bridge girder 2 is used as a reaction material.

The back blocks 31 and 32 are provided with recesses 33 that face the individual recesses 22 of the main body block 21 and form a space that encloses the anti-slip bar 5. The back blocks 31 and 32 are provided with protrusions that are combined with each other for easy installation side by side. Further, similarly to the main body block 21, a taper portion 34 is provided on the upper surface of the rear block (31, 32) for easy removal. Both the taper portion 26 of the main body block 21 and the taper portion 34 of the rear block (31, 32) are inclined so as to become lower toward the recess, and both are boundary surfaces where the main body block 21 and the rear block (31, 32) contact each other. It has a shape that is the lowest at the top.
The rear block (31, 32) further includes a fixing screw hole 35 at a position corresponding to the fixing screw insertion hole 28 of the main body block 21 so as to be fixed in combination with the main body block.

4A and 4B are views for explaining a method of installing the reinforcing member according to the embodiment of the present invention. FIG. 4A is an intermediate stage of attaching the main body block 21, and FIG. The final stage is shown.
Referring to FIG. 4( a ), the back blocks 31 and 32 are combined with the projections of the back blocks 31 and 32 on the two back surfaces near the side ends of the steel bridge girder 2 out of the anti-slip bars 5 exposed by removing the concrete. Thus, the main body block 21 is installed so as to be installed side by side, and the main body block 21 is installed in combination with the installed rear block (31, 32).

When the back block (31, 32) is installed, the recess 33 of the back block (31, 32) is arranged so as to face the anti-slip bar 5, and the main body block 21 has the recess 22 enclosing the anti-slip bar 5, The blocks (31, 32) are attached so as to face the recesses 33. Therefore, the pitch of the recesses 33 and the pitch of the recesses 22 of the main body block 21 when the back blocks 31 and 32 are provided side by side are formed in accordance with the pitch of the shift preventing streaks 5.

The main body block 21 is pushed toward the rear block (31, 32) so that the groove portion 23 sandwiches the girder flange of the steel bridge girder 2, and the fixing screw for connecting the rear block (31, 32) is inserted with the fixing screw. The screw is inserted through the hole 28, and a fixing screw is attached to the fixing screw hole 24 and fixed to the girder flange of the steel bridge girder 2.
Next, as shown in FIG. 4B, the mortar injection pipe 29 is used to inject the mortar 30 from the injection hole 25 into the space formed by the recesses 22 and 33 to cure it. The mortar 30 uses a plastic non-shrinkable material that exhibits a strength of 40 N/mm ^{2 in} 15 hours, so that the required strength can be obtained in a short time.

The injection of the mortar 30 is not limited to the space formed by the recesses 22 and 33, and the mortar 30 including the taper portion 26 of the main body block 21 and the taper portion 34 of the back block (31, 32) is mixed with the concrete above the reinforcement member 20. Do so as to fill the voids. Therefore, although not shown, in the embodiment, during the injection of the mortar 30, the mortar 30 overflows from the space formed by the recesses 22 and 33 so as not to drop around the reinforcement member 20. A thin aluminum plate is installed as a gable frame. As a result, the injected mortar 30 can be retained between the reinforcing member 20 and the concrete grinding surface of the upper part of the reinforcing member 20, and a state in which the mortar 30 is densely packed can be created.

After the mortar 30 is hardened, the anti-slip bar 5 and the reinforcing member 20 are integrated by the mortar 30, and the voids in the upper part of the reinforcing member 20 are also filled with the mortar 30, so that the floor slab 3 can be removed. For the time being, it has sufficient strength to be used for the passage of vehicles.

When the concrete around the anti-slip bar 5 is removed for a certain section, the floor slab 3 and the steel bridge girder 2 in the section where the concrete is removed tend to be individually deformed against an external load such as traffic of a vehicle. For this reason, the anti-slip bar 5 may be subjected to bending stress as well as vertical load, and there is a concern that it may be fractured which is difficult to occur only with vertical load. Therefore, the shift preventing bar 5 and the reinforcing member 20 are integrated by the mortar 30, so that the bending stress related to the shift preventing bar 5 is relaxed and the safety is secured.
As described above, the reinforcing member 20 is installed for every two adjacent detent bars to the one detent bar 5 near the side end of the steel bridge girder 2 over the predetermined section where the concrete is removed. Then, the temporary reinforcement of the predetermined section is completed.

On the other hand, at the stage of removing the floor slab 3, the reinforcing member 20 is first removed. In this case, the fixing screws attached to the fixing screw insertion hole 28 and the fixing screw hole 24 are removed, and the pushing bolt is pushed into the screw hole 27 for the pushing bolt. By screwing in, the main body block 21 is pushed out by receiving a reaction force from the hardened mortar 30, so that it can be easily removed.
Since the reinforcing member 20 has a combined structure of the main body block 21 and the back block (31, 32), it can be easily installed and removed, and can be reused after the removal, so once the required number is manufactured, the next time It is possible to prevent an increase in construction costs thereafter.

FIG. 5 is a flowchart illustrating a method of removing a floor slab of a composite girder bridge according to an exemplary embodiment of the present invention.
Referring to FIG. 5, the work of removing the floor slab 3 of the composite girder bridge 1 is performed as a preparatory step while the road is in service. In step S520, the reinforcing member 20 is installed in the portion where the concrete is removed, and temporary reinforcement is performed. The concrete removal of the floor shunt haunch portion 4 and the installation of the reinforcing member 20 will be described in detail below with reference to FIGS.

FIG. 6 is a flowchart for explaining a method of removing concrete of the floor slab haunch part 4 with a water jet according to the embodiment of the present invention.
The flowchart of FIG. 6 is provided with a bridge axial direction moving base 12 and a right angle moving base 14 on the side of the floor slab haunch part 4 of the composite girder bridge 1 before starting the concrete removal, and the nozzles are arranged in the bridge axial direction and It is premised that the water jet device 10 that can move freely along the direction perpendicular to the bridge axis is installed. In addition, as described above, in order for the water jet to effectively contribute to the cutting, the slope of the side surface of the floor slab haunch 4 is mechanically preliminarily machined so that the water jet hits vertically, and the vertical surface is projected. It is assumed that

In step S610, the nozzle of the water jet is reciprocated in the bridge axis direction to remove the concrete on one side surface of the floor shunt haunch portion 4 of the composite girder bridge 1 until the first row of the retaining bars 5 is visible. As the nozzle, a front jet nozzle 15 that jets a water jet in the extending direction of the nozzle is used. However, the water jet used in step S610 is not a general use for cutting a workpiece, but has a width to secure a space for passing a nozzle or installing a reinforcing member 20 between the anti-shift bars 5. Since it is necessary to remove the concrete, the front injection nozzle 15 that injects the water jet at an angle of 5° to 9° with respect to the extending direction of the nozzle is used while being rotated.

Concrete removal of the floor slab haunch part 4 is carried out from the side of the floor slab 3 while maintaining the upper surface of the floor slab 3 so as not to obstruct the passage of vehicles on the floor slab, so In order to avoid problems, find a specific section where concrete can be removed at once, and carry out within the specified section.

After the concrete has been removed by cutting until the first row of the detent bars 5 in the predetermined section can be seen, the nozzle is used as it is without being replaced, and the nozzle of the water jet is moved between the adjacent detent bars 5 in step S620. While moving in the direction perpendicular to the bridge axis, the concrete is cut and removed to the other side surface of the floor slab portion 4 of the composite girder bridge 1. At this time, the nozzle may move only in the direction perpendicular to the bridge axis without moving in the direction of the bridge axis, or may move in the direction perpendicular to the bridge axis while reciprocating between the adjacent detent bars 5. You may do it.

When the concrete between the detent bars 5 adjacent to each other in each predetermined section is repeated by cutting and removing the concrete between the detent bars 5 adjacent to each other in the bridge axis direction within a predetermined section, the front injection is performed in step S630. The nozzle 15 is replaced with a side jet nozzle 16 which jets a water jet in a direction perpendicular to the stretching direction, and the concrete between the detent bars 5 arranged in the direction perpendicular to the bridge axis is removed by cutting. At this time, the side jet nozzle 16 is moved in the direction perpendicular to the bridge axis to remove the concrete between the anti-slip bars 5. The concrete between the detent bars 5 arranged in the direction orthogonal to the bridge axis is removed row by row, and when the removal of the concrete around the detent bars 5 in the predetermined section is completed, the concrete removal is finished (step S640).

FIG. 7 is a flowchart illustrating a method of installing a reinforcing member according to an exemplary embodiment of the present invention.
Referring to FIG. 7, in step S710, the back block (31, 32) of the reinforcing member 20 is installed on the back surface of the anti-slip bar 5. The reinforcing member 20 is installed on the one row of the anti-shift bars 5 near the side end of the steel bridge girder 2. In the embodiment, one reinforcing member 20 is installed on each of the two anti-post bars, so that the rear surface As for the block, a back block 31 is installed on one back surface of two adjacent detent bars 5, and a back block 32 is installed on the other back surface. At this time, the recesses 33 of the back block (31, 32) are arranged so as to face the anti-slip bars 5 located on the front surfaces of the blocks.

In step S720, the body block 21 of the reinforcing member 20 is aligned with the back block (31, 32) and fixed to the girder flange of the steel bridge girder 2.
The main body block 21 is attached so that the groove 23 sandwiches the girder flange of the steel bridge girder 2, and the recess 33 of the main body block 21 surrounds the anti-slip bar 5 and faces the recess 33 of the back block (31, 32). And fix it to the girder flange of the steel bridge girder 2 with the fixing screw. Further, the body block 21 and the back block (31, 32) are also fixed by fixing screws. As a result, spaces for individually enclosing the anti-slip lines 5 are formed.

Next, in step S730, the mortar 30 is injected from the injection hole 25 of the main body block 21 into the space surrounding the anti-slip bar 5 to cure it, and the anti-slip bar 5 and the reinforcing member 20 are fixed. The mortar 30 injected at this time overflows to the upper part of the reinforcing member 20 and is injected so as to fill the space between the reinforcing member 20 and the concrete located on the upper part of the reinforcing member 20. Thereby, the reinforcing member 20 and the mortar 30 filled on the reinforcing member 20 play a role of receiving a load from the floor slab 3 located above.
When the reinforcement members 20 have been installed on all of the one row of the anti-shift bars 5 near the side ends of the steel bridge girders 2 within the predetermined section, the installation of the reinforcement members 20 is completed (step S740).

Referring again to FIG. 5, after the concrete removal of the floor slab haunch portion 4 and the installation of the reinforcing member 20 described above, in step S530, the concrete removal of the floor slab haunch portion 4 of the floor slab removal section and the reinforcement member 20 are performed. Make sure the installation is complete. Steps S510 and S520 are performed in units of a predetermined section set based on the structural analysis. Since the floor slab removal section is usually longer than the predetermined section, it is necessary to remove the concrete of the floor slab haunch part 4 and install the reinforcement member 20 in predetermined section units until the installation of the reinforcing member 20 is completed for all the floor slab removal sections. repeat.
During steps S510 to S530, a floor slab removal preparation period is performed, and the floor slab can be used as a road while maintaining the upper surface.

After step S530 is completed, the vehicle is stopped from passing, and then the reinforcing member 20 is removed in step S540. Removal of the reinforcing member 20 is performed by removing a fixing screw that joins the main body block 21 and the back block (31, 32) of the reinforcing member 20 and a fixing screw that fixes the main body block 21 to the girder flange of the steel bridge girder 2, Since the main body block 21 is pushed back by tightening the push bolt into the screw hole 27 for the push bolt, this can be easily performed.

Next, in step S550, the floor slab 3 is cut into blocks having a size that is easy to convey, and unnecessary shift preventing streaks 5 are cut (step S560). The order of steps S550 and S560 may be interchanged, or the steps may be performed independently and simultaneously in parallel.
Unlike the conventional method of treating the portion directly above the bridge girder later, in the embodiment according to the present invention, the concrete of the portion immediately above the bridge girder is removed first, so there is no need to cut the slab around the portion just above the bridge girder, and the floor There is no restriction on the cutting position of the plate 3. Therefore, by cutting the floor slab 3 into a block of a size that can be carried out, the total cutting distance of the floor slab 3 to be removed can be shortened.
The unnecessary shift preventing muscles 5 in step S560 are the shift preventing muscles 5 other than the minimum necessary shift preventing muscles 5 that support the floor slab 3 so as not to fall down. Plasma cutting is used to cut the anti-slip bar 5 even in a narrow area in a short time, and thermal deterioration does not occur in the adjacent girder flange.

Next, in step S570, while the floor slab is being lifted by the crane, the remaining anti-shift bars 5 are cut and completely separated from the steel bridge girder 2. At this time as well, plasma cutting is used to cut the remaining anti-slip bar 5 in a short time.
Finally, the separated floor slab block is carried out (step S580), and the floor slab removal is completed.

According to the method of removing the floor slab of the composite girder bridge according to the present invention, the concrete around the slip-stop bar of the composite girder bridge, which requires a lot of man-hours for the removal, is temporarily removed and temporarily reinforced by the reinforcing member, so that the vehicle It is possible to create a state where it is easy to remove after securing safety in advance without stopping the passage of traffic such as. Therefore, the work period for removing the floor slab after stopping the passage of the vehicle can be significantly shortened as compared with the conventional method.

Although the embodiments of the present invention have been described in detail above with reference to the drawings, the present invention is not limited to the above-described embodiments, and various modifications are made without departing from the technical scope of the present invention. It is possible to

1 Composite girder bridge 2 Steel bridge girder 3 Floor slab 4 Floor slab haunch part 5 Anti-slip bar 10 Water jet device 11 Traveling platform 12 Bridge axial direction platform 13 Right angle platform 14 Right angle platform 15 Forward injection nozzle 16 Side injection Nozzle 20 Reinforcing member 21 Main body block 22, 33 Recessed portion 23 Groove portion 24, 35 Fixing screw hole 25 Injection hole 26, 34 Tapered portion 27 Screw hole for extrusion bolt 28 Fixing screw insertion hole 29 Mortar injection pipe 30 Mortar 31, 32 Rear block

Claims (5)

Keeping the upper surface of the floor slab so as not to obstruct the passage of the vehicle, leaving a slip-prevention streak from the side of the floor slab haunch part, remove the concrete area around the detent streak of the floor slab hunch part with a water jet Stage
Installing and fixing a reinforcing member around a specific anti-slip bar in the section where the concrete has been removed,
After stopping the passage on the floor slab, there is a step of removing the reinforcing member and cutting the anti-slip bar to remove the floor slab,
A synthetic girder bridge characterized in that the step of removing the concrete in a predetermined section and the step of installing and fixing a reinforcing member are repeated while changing the section to remove the concrete in the floor plate haunch part in the section in which the floor plate is removed. How to remove the floor slab. The step of removing a specific section of the floor slab haunch part with a water jet,
A step of reciprocating the nozzle of the water jet in the bridge axis direction and cutting off concrete until one side of the floor girder part of the composite girder can be seen until the first row
A step of cutting and removing concrete up to the other side of the floor girder part of the composite girder bridge while moving the nozzle of the water jet between the adjacent detent bars in the direction perpendicular to the bridge axis,
The step of exchanging the nozzle with a nozzle ejecting in a direction perpendicular to the extending direction and cutting and removing the concrete between the detent bars arranged in the direction perpendicular to the bridge axis. How to remove the floor slab of a synthetic girder bridge. The step of installing the reinforcing member includes
A step of installing a plurality of back blocks having recesses facing the back surface of the anti-shift bar so that the recesses oppose the back surface of the anti-shift bar;
Install a body block on the girder flange that has a plurality of recesses for enclosing the girder flange of the bridge girder and the recesses of the back block corresponding to the recesses of the back block. Combining multiple back blocks to enclose
The method of removing a floor slab of a composite girder bridge according to claim 1, further comprising the step of injecting mortar into a space surrounding the anti-slip bar to fix the anti-slip bar and the reinforcing member. The step of removing the reinforcing member, cutting the anti-slip bar, and removing the floor slab,
The step of removing the reinforcing member,
Cutting the floor slab into blocks,
Cutting the anti-slip muscles other than the anti-slip muscles necessary for fixing the floor block,
The step of unloading the remaining anti-slip bar in a state where the floor slab block is lifted and carrying out the floor slab block, the composite girder bridge according to any one of claims 1 to 3. How to remove the floor slab.
A reinforcing member used to reinforce the section where the concrete has been removed when removing the deck of the composite girder bridge.
A main body block including a groove portion for sandwiching a girder flange of a bridge girder, a plurality of recesses for enclosing the anti-slip bar, and an injection hole for injecting mortar into the recesses,
A plurality of back blocks that face each recess of the main body block and form a space that encloses the anti-slip line, and a reinforcing member.

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