JP7020978B2 - How to remove the floor slab of synthetic girders - Google Patents

Description

The present invention relates to a method for removing a floor slab of a synthetic girder for removing a floor slab from an existing bridge made of a synthetic girder and constructing a new floor slab.

Conventionally, many bridges such as general roads and highways use synthetic girders in which a floor slab made by placing concrete on the main girder is installed. In the synthetic girder, a plurality of studs as slip prevention members are provided on the upper surface of the main girder, and the concrete of the floor slab is placed with the studs embedded, so that the main girder and the floor slab are connected by the studs. ..

When the floor slab becomes old, the floor slab is replaced by removing the existing floor slab and reconstructing a new floor slab (see, for example, Patent Document 1). 42 to 45 show a floor slab removal method in the conventional floor slab replacement construction.

In the conventional floor slab removal method, first, in the composite girder 1, the floor slab 2 to be removed is cut in the direction perpendicular to the bridge axis, and as shown in FIG. 42, a part of concrete 4 is left on the main girder 3 to make a floor. The plate 2 is cut in the bridge axis direction at a plurality of cutting positions C in the direction perpendicular to the bridge axis. Next, as shown in FIG. 43, the concrete other than the concrete 4 on the main girder 3 is lifted by a crane or the like and removed. After that, as shown in FIG. 44, the concrete 4 remaining on the main girder 3 is crushed by a crusher 5 such as a large breaker or a hand breaker, and the concrete debris generated in the crushing operation is removed and collected. Then, as shown in FIG. 45, the stud 3a is cut and removed, the residual concrete debris is removed, and then the surface of the main girder 3 is finished.

Japanese Unexamined Patent Publication No. 2016-12148

However, in the conventional floor slab removal method, it is necessary to cut the floor slab 2 on the main girder 3 at a plurality of points in the bridge axis direction and individually remove the floor slab 2 divided into a large number in the direction perpendicular to the bridge axis. Therefore, it takes a long time to cut and remove the floor slab 2. In addition, the crushing work of the residual concrete 4 on the main girder 3 generates a large amount of concrete debris, which requires a great deal of time and effort for collecting the debris, and it is necessary to remove the concrete between the reinforcing bars and the studs. And it takes a long time to collect. For this reason, there is a problem that the traffic regulation time during the construction period becomes long, and the influence on the traffic on the high-traffic road bridge becomes large. In addition, there is a problem that noise, vibration, and dust are remarkably generated by the crushing work of the concrete 4, and it is not suitable for work in an urban area.

The present invention has been made in view of the above problems, and an object thereof is to improve the efficiency of the work of cutting and removing the floor slab and to remove the concrete remaining on the main girder. The purpose is to provide a method for removing the floor slab of the synthetic girder that can be mitigated.

In the present invention, in order to achieve the above object, a concrete floor slab is installed on the main girder, and a floor slab is formed from a synthetic girder in which the main girder and the floor slab are connected by a slip prevention member provided on the upper surface of the main girder. In the method of removing the deck of the synthetic girder, the first cutting step of cutting the deck in the deck removal section at a plurality of points in the direction of the bridge axis in the direction perpendicular to the bridge axis, and between the main girder and the deck. The first includes a second cutting step of cutting the concrete together with the slip-preventing member together with a wire saw by a predetermined length in the direction of the bridge axis, and a removal step of lifting and removing the deck cut in the second cutting step. In the cutting process, after cutting the existing deck concrete from the upper surface to a predetermined depth with a wet concrete cutter, the remaining concrete is cut to the lower surface with a dry concrete cutter, and the second cutting step and the removing step are performed. Is repeated from one end to the other end in the bridge axis direction of the deck removal section.

As a result, after the deck in the deck removal section was cut in the direction perpendicular to the bridge axis at multiple points in the bridge axis direction, the concrete between the main girder and the deck was cut by a predetermined length in the bridge axis direction. Since the deck is removed, the deck divided by a predetermined length in the bridge axis direction can be removed with the full width without dividing in the direction perpendicular to the bridge axis. Further, since the concrete between the main girder and the floor slab is cut by the wire saw together with the slip prevention member, the amount of concrete remaining on the main girder is extremely small. Further, since the first cutting step and the removing step are repeated from one end to the other end in the bridge axis direction of the deck removing section, the deck removing work can be performed on the deck before being separated from the main girder. It will be possible. Further, in the first cutting step, after the concrete of the existing floor slab is cut from the upper surface to a predetermined depth by the wet concrete cutter, the remaining concrete is cut to the lower surface by the dry concrete cutter. The cutting is performed in combination with.

According to the present invention, the existing deck divided by a predetermined length in the bridge axis direction can be removed without being divided in the direction perpendicular to the bridge axis, and the deck can be removed in the direction perpendicular to the bridge axis as in the conventional case. It is not necessary to divide it into multiple parts and remove it, and the number of divisions of the deck to be removed can be significantly reduced. As a result, the floor slab can be cut and removed efficiently, and the construction period can be shortened. Further, since the amount of concrete remaining on the main girder can be extremely reduced, the concrete removal work on the main girder can be significantly reduced. Further, since the floor slab can be removed on the floor slab before it is separated from the main girder, for example, the floor slab removal work should be performed while moving the device for removing and transporting the floor slab on the floor slab. Can be done. Further, in the first cutting step, the existing floor slab concrete can be cut at low cost while preventing the sewage from falling under the girder by cutting using both the wet type and the dry type. That is, wet cutting requires treatment of the water used for cooling, but has the advantage of being cheaper than the dry type, while the dry type does not generate sewage, but is a large vacuum device for recovering cutting powder. Since the cost is higher and the maximum depth is smaller than the wet type, the cutting cost is increased by cutting most of the existing deck in the thickness direction with the wet type and the remaining small part with the dry type. It is possible to take measures against sewage as well as suppress the problem.

Perspective view of main girder and floor slab showing one embodiment of the present invention Top view of main girder and deck showing the first cutting step Front sectional view of main girder and deck showing the first cutting step Front sectional view of the floor slab showing the first cutting step Front sectional view of the floor slab showing the first cutting step Top view of main girder and deck showing the second cutting step Front sectional view of main girder and deck showing the second cutting step Front sectional view of main girder and deck showing the second cutting step Planar sectional view of main girder and deck showing the second cutting step Planar sectional view of main girder and deck showing the second cutting step Side sectional view of main girder and deck showing the second cutting step Side sectional view of main girder and deck showing the second cutting step Side sectional view of main girder and deck showing the removal process Side sectional view of main girder and deck showing the removal process An exploded perspective view of the main girder and deck showing the removal process Side view of the first suspension device of the deck removal device Top view of the first suspension device Front view of the first suspension device Front view of the first suspension device Side view of the second suspension device Top view of the second suspension device Front view of the second suspension device Side view of the transport trolley Top view of the transport trolley Front view of the transport trolley Side view of the bridge showing the deck removal process Side view of the bridge showing the deck removal process Side view of the bridge showing the deck removal process Floor plan of the bridge showing the deck removal process Side view of the floor slab removal device showing the floor slab removal process Side view of the floor slab removal device showing the floor slab removal process Side view of the floor slab removal device showing the floor slab removal process Side view of the floor slab removal device showing the floor slab removal process Side view of the floor slab removal device showing the floor slab removal process Side view of the floor slab removal device showing the floor slab removal process Side view of the floor slab removal device showing the floor slab removal process Side view of the floor slab removal device showing the floor slab removal process Side view of the floor slab removal device showing the floor slab removal process Side view of the floor slab removal device showing the floor slab removal process Side view of the floor slab removal device showing the floor slab removal process Flow chart showing the floor slab removal process Front view showing the conventional floor slab removal process Front view showing the floor slab removal process Front view showing the floor slab removal process Front view showing the floor slab removal process

1 to 41 show an embodiment of the present invention, and show a method for removing an existing deck from a bridge.

The bridge 10 shown in the figure is composed of a plurality of piers 11 arranged at intervals in the direction of the bridge axis, a main girder 12 supported by the pier 11, and an existing floor slab 13 erected on the main girder 12. Become.

The main girder 12 is made of a steel girder having an upper flange 12b and a lower flange 12c at the upper end and the lower end of the web 12a, respectively, and is arranged in a plurality of rows (for example, three rows) at intervals in the direction perpendicular to the bridge axis. Further, on the upper surface of the upper flange 12b, a gibber 12d as a plurality of slip prevention members for connecting the main girder 12 and the floor slab 13 is provided. The gibber 12d is made of a so-called stud gibber, which is formed by a metal rod-shaped member extending in the vertical direction and has a head having a head having a larger outer diameter than other portions at the upper end. A plurality of (for example, three) gibber 12d are provided in the direction perpendicular to the bridge axis, and the girders 12 are arranged at intervals in the bridge axis direction from one end side to the other end side in the longitudinal direction of the main girder 12. The gibber 12d shown in this embodiment is an example, and a member having another shape may be used as the slip prevention member.

The deck 13 is formed of concrete cast on the upper flange 12b of each main girder 12 by a formwork (not shown), and wall railings 13a are integrally formed on both sides in the width direction thereof. In the deck 13, the main girder 12 and the deck 13 are connected by each gibber 12d by placing concrete with each gibber 12d embedded therein. Further, on the lower surface side of the floor slab 13, haunches 13b located on the upper flanges 12b of each main girder 12 are provided, and each haunch 13b is formed so as to project downward. In this case, the side surface of the haunch 13b is formed so as to form an inclined surface from both sides of the upper flange 12b to the lower surface of the deck 13.

Next, the floor slab removal method in the present embodiment will be described. In the floor slab removal method of the present embodiment, the first cutting step of cutting the existing deck 13 in the direction perpendicular to the bridge axis and the concrete between the existing deck 13 and the main girder 12 are cut together with the stud with a wire saw. The second cutting step and the removing step of lifting and removing the existing deck 13 cut in the second cutting step are included, and the second cutting step and the removing step are performed from one end of the deck removing section N. The existing floor slab 13 is removed from the main girder 12 by repeating the process to the end. The floor slab removing device shown in FIGS. 16 to 24 is used in the removing step, and the detailed configuration of the floor slab removing device will be described later.

First, in the first cutting step, as shown in FIG. 2, the existing floor slab 13 is formed in the direction perpendicular to the bridge axis at a plurality of positions C in the bridge axis direction so that the length in the bridge axis direction after cutting is L. Disconnect. It is assumed that the length L in the bridge axis direction of the deck 13 is sufficiently shorter than the length W in the direction perpendicular to the bridge axis. In this case, the portion not including the wall height column 13a (the floor slab covering almost the entire road surface) is set as the first cutting range C1, and the other part including the wall height column 13a is set as the second cutting range C2. Cut as follows for each range C1 and C2.

In the first cutting range C1, as shown in FIG. 4, the concrete of the existing deck 13 is first cut from the upper surface to a predetermined depth T1 (for example, 150 mm) by a wet concrete cutter 70, and then as shown in FIG. The remaining concrete having a predetermined depth T2 (for example, 20 mm) is cut to the lower surface by a dry (anhydrous) concrete cutter 71. At that time, by attaching a curing member 72 such as a sponge to the lower surface of the existing floor slab 13 along the cutting position C, the cutting powder does not scatter below the bridge girder when the concrete is cut to the lower surface by dry cutting. To do so. The second cutting range C2 is cut with a wire saw.

Next, in the second cutting step, first, as shown in FIGS. 6 and 7, a plurality of through holes 13c for a wire saw are formed in the existing deck 13. Two through holes 13c are provided for each main girder 12 so as to be located on both sides of the main girder 12 in the width direction (direction perpendicular to the bridge axis), for example, by drilling concrete with a well-known core drill. In this case, the through hole 13c is provided in the existing deck 13 which is the third from one end side (right side in the figure) of the deck removal section N among the existing decks 13 between the cutting positions C in the direction perpendicular to the bridge axis. At the same time, every other existing floor slab 13 between the cutting positions C is provided on the fifth and subsequent existing floor slabs 13.

Subsequently, the first and second existing floor slabs 13 from one end side of the floor slab removal section N are separated from the main girder 12 by a wire saw 80 as follows. The wire saw 80 extends from the drive device 81 in an annular shape, and has a well-known configuration for cutting the object to be cut by pulling the wire saw 80 wound around the object to be cut while rotating the wire saw 80 at high speed by the drive device 81. In this case, the drive device 81 is formed so as to be able to be installed on the existing floor slab 13 across the rail 50 described later.

That is, as shown in FIG. 9, the drive device 81 of the wire saw 80 is arranged on the upper surface of the third existing floor slab 13, and the wire saw 80 extending from the drive device 81 penetrates the lower surface side of the existing floor slab 13. While passing through the hole 13c, as shown in FIGS. 9 and 11, a wire saw 80 is attached to the end surface of the first existing deck 13 on one end side in the bridge axial direction from both sides in the width direction of the upper flange 12b of the main girder 12. Hand over. Subsequently, the drive device 81 is driven, and as shown in FIGS. 10 and 12, the concrete (haunch 13b) between the first and second existing floor slabs 13 and the upper flange 12b of the main girder 12 is wire sawed. Cut in the direction of the bridge axis at 80. In this case, as shown in the figure, three wire saws 80 and a drive device 81 arranged for each main girder 12 may be used, or one wire saw 80 and a drive device 81 may be used at the positions of the main girders 12. The cutting may be performed sequentially.

Next, as shown in FIG. 13, the first existing floor slab 13 is lifted and removed, and then the second existing floor slab 13 is lifted and removed as shown in FIG.

After that, the drive device 81 of the wire saw 80 is moved to the fifth existing floor slab 13, and the second cutting step and the removal step are repeated to perform all the existing floor slabs in the floor slab removal section N. Remove 13 The main girder 12 from which the existing floor slab 13 has been removed is subjected to surface finishing of the upper flange 2b after removing a small amount of concrete (haunch 13b) remaining on the upper surface of the upper flange 2b and a part of the stud 13d.

Here, a floor slab removing step of removing the existing floor slab 13 by using the floor slab removing device installed on the floor slab 13 will be described with reference to FIGS. 16 to 41. 16, FIG. 20, FIG. 23, and FIGS. 30 to 40 are side views of the floor slab removing device as viewed from the direction of arrow AA in FIG.

The floor slab removing device shown in the figure is a gate-type first and second lifting devices 20 and 30 for lifting and lowering the existing floor slab 13, and a first lifting device 20 and a second lifting device 30. A transport trolley 40 for transporting the floor slab 13 is provided between the first suspension device 20 and the transport trolley 40 so as to move in the bridge axis direction along the rail 50.

The first suspension device 20 includes a pair of left and right first frames 21 extending in the bridge axis direction, and a pair of left and right second frames extending downward from one end side and the other end side of each first frame 21 in the bridge axis direction. The frame 22, a pair of left and right first guide rails 23 extending in the bridge axis direction, an annular second guide rail 24 moving in the bridge axis direction along the first guide rail 23, and a second guide rail. It is composed of a suspension balance 25 that rotates along 24 and a plurality of self-propelled traveling units 26 that travel by engaging with the rail 50.

Each first frame 21 is formed in a cantilever shape having both ends extending longer in the bridge axis direction than each second frame 22, and is connected to each other by a plurality of cross beams 21a extending in the direction perpendicular to the bridge axis. ..

The upper end of each second frame 22 is connected to the first frame 21, and the lower end side is connected to each other by a plurality of cross beams 22a extending in the bridge axis direction.

Each first guide rail 23 is formed slightly longer than the first frame 21, and is fixed to each cross beam 21a of each first guide rail 23.

The second guide rail 24 is connected to each first guide rail 23 via a support mechanism 24a at four points in the circumferential direction, and each support mechanism 24a connects one end side to the other end of each first guide rail 23. It is designed to move to the side. As each support mechanism 24a, for example, a well-known electric trolley can be used.

The suspension balance 25 is formed so as to extend linearly in the horizontal direction, and two points in the longitudinal direction are connected to the second guide rail 24 via the support mechanism 25a, respectively, and the second guide rail is connected by each support mechanism 25a. It is designed to rotate in the circumferential direction of 24. As each support mechanism 25a, for example, a well-known geared trolley can be used. Further, the suspension balance 25 is provided with a plurality of suspension members 25b at intervals in the longitudinal direction of the suspension balance 25, and the floor slab 13 is suspended by each suspension member 25b. As each suspension member 25b, for example, a well-known manual chain block can be used.

Each traveling unit 26 is provided at the lower end of each second frame 22. The traveling unit 26 is provided with a pair of front and rear wheels 26a, and each wheel 26a is driven by a motor (not shown).

The second suspension device 30 includes a pair of left and right first frames 31 extending in the bridge axis direction, and a pair of left and right second frames extending downward from one end side and the other end side of each first frame 31 in the bridge axis direction. It is composed of a frame 32 and a suspension balance 33 extending in the direction of the bridge axis.

Each of the first frames 31 is formed so that both ends thereof are located substantially at the upper ends of the second frames 32, and is connected to each other by a plurality of cross beams 31a extending in the direction perpendicular to the bridge axis.

The upper end of each second frame 32 is connected to the first frame 31, and the lower end side is connected to each other by a plurality of cross beams 32a extending in the bridge axis direction.

The suspension balance 33 is formed so as to extend linearly in the horizontal direction, and is fixed to each cross beam 31a of the first frame 31 so as to be located at the center in the direction perpendicular to the bridge axis. A plurality of suspension members 33a are provided on the suspension balance 33 at intervals in the longitudinal direction of the suspension balance 33, and the floor slab 13 is suspended by each suspension member 33a. As each suspension member 33a, for example, a well-known manual chain block can be used.

The transport trolley 40 is a plurality of self-propelled type traveling by engaging with a pair of left and right first frames 41 extending in the direction of the bridge axis, a pair of front and rear second frames 42 extending in the direction perpendicular to the bridge axis, and a rail 50. It is composed of the traveling unit 43 of the above.

Each first frame 41 is formed so that both ends extend longer in the bridge axis direction than each second frame 42, and are spaced apart from each other by a length shorter than the bridge axis length L of the deck 13. Have been placed.

Each second frame 42 is bent so that the center side in the direction perpendicular to the bridge axis is located below both ends, and each first frame 41 is fixed to the center side in the direction perpendicular to the bridge axis.

Each traveling unit 43 is provided at both ends of each second frame 42. The traveling unit 43 is provided with a pair of front and rear wheels 43a, and each wheel 43a is driven by a motor (not shown).

The rail 50 has a rail 51 arranged at right angles to each other in the direction perpendicular to the bridge axis, and a fixing member 52 to which the rail 51 is fixed at the upper end, and the rail 51 and the fixing member 52 are on the existing deck 13 or. A pair of existing floor slabs 13 are arranged on the main girder 12 from which the existing deck 13 has been removed at right angles to each other in the direction perpendicular to the bridge axis. The rail 50 is configured such that a rail 51 and a fixing member 52 formed in a length 2L that is twice the length L in the bridge axial direction of the deck 13 are connected in the bridge axial direction. In this case, the left and right rails 51 and the fixing members 52 are arranged at equal intervals with the main girders 12 at both ends in the direction perpendicular to the bridge axis, and the left and right fixing members 52 are connected to each other via a plurality of reinforcing members 53. Further, when the rail 50 is installed on the main girder 12 from which the existing floor slab 13 has been removed, a pillow wood 54 having a height equal to that of the floor slab 13 is arranged between the fixing member 52 and the main girder 12.

Next, the floor slab removing step using the floor slab removing device will be described with reference to FIGS. 26 to 40.

First, as shown in FIG. 27, the existing deck 13 is cut at a plurality of positions C in the bridge axis direction in the direction perpendicular to the bridge axis by the first cutting step. In this case, the length L in the bridge axis direction of the deck 13 is sufficiently shorter than the length W in the direction perpendicular to the bridge axis.

Next, as shown in FIGS. 28 and 29, the rail 50 is laid on the existing deck 13 cut in the direction perpendicular to the bridge axis. At that time, the rail 50 extends from the position excluding the two existing decks 13 on one end side of the deck removal section N to the other end side of the deck removal section N and on the existing deck 13 outside the deck removal section. To lay. The area outside the floor slab removal section may be on a newly installed floor slab for which the floor slab replacement work has already been completed.

Subsequently, as shown in FIG. 30, the first suspension device 20, the second suspension device 30, and the transport carriage 40 are arranged. The first suspension device 20 is arranged so as to be able to travel on the rail 50, and is located on one end side of the deck removal section N. The second suspension device 30 is arranged on the existing deck 13 outside the deck removal section, and each second frame 32 is installed so as to be located outside the rail 50. The transport carriage 40 is arranged so as to be able to travel on the rail 50, and reciprocates between the first suspension device 20 and the second suspension device 30.

Next, the concrete between the existing deck 13 and the main girder 12 on one end side of the deck removal section N is cut by the second cutting step.

Subsequently, as shown in FIG. 31, the suspension balance 25 of the first suspension device 20 is positioned on one end side of the first suspension device 20, and each suspension member 25b is placed on the most end side of the deck removal section N. The existing floor slab 13 is connected to the existing floor slab 13 located in the above via a rope 25c, and the existing floor slab 13 is lifted by each hanging member 25b as shown in FIG. 32. At that time, the direction of the suspension balance 25 is such that the longitudinal direction is perpendicular to the bridge axis. Further, the transport carriage 40 is located on the other end side of the first suspension device 20.

Next, as shown in FIG. 33, the suspension balance 25 of the first suspension device 20 is rotated 90 degrees so that the longitudinal orientation of the suspension balance 25 and the existing deck 13 is perpendicular to the bridge axis, and FIG. 34 As shown in the above, the suspension balance 25 and the existing deck 13 are moved to the other end side of the first suspension device 20 by the second guide rail 24.

After that, as shown in FIG. 35, the existing floor slab 13 is suspended from the suspension balance 25 onto the transport trolley 40, and as shown in FIG. 36, the transport trolley 40 on which the existing floor slab 13 is mounted is moved to the second suspension device 30. Moving.

Subsequently, as shown in FIG. 37, after the existing floor slab 13 is lifted by each hanging member 33a of the suspension balance 33 of the second suspension device 30, the transport carriage 40 is moved to the other end side of the first suspension device 20. Moving. At that time, the first suspension device 20 is moved toward the other end side of the floor slab removal section N by the length L of one of the existing floor slabs 13, and the suspension balance 25 is moved to the other end side of the floor slab removal section N, and the suspension balance 25 is moved to the first suspension device 20. Move to one end side.

Next, as shown in FIG. 38, the existing floor slab 13 is suspended from the suspension balance 33 on the transport vehicle 60 (truck) that has entered the inside of the second suspension device 30, and the existing floor slab 13 is externally mounted by the transport vehicle 60. Carry out to. Further, the suspension balance 25 of the first suspension device 20 is rotated by 90 degrees so that the direction in the longitudinal direction is the bridge axis direction.

After that, the concrete between the next existing floor slab 13 and the main girder 12 is cut together with the studs in the same manner as described above, and as shown in FIG. Lift the floor slab 13. After removing the second existing floor slab 13 by the same process as described above, as shown in FIG. 40, the first suspension device 20 is attached to the floor slab removal section N by the length L of one of the existing floor slabs 13. While moving toward the other end side of the rail 50, the rail 51 and the fixing member 52 of the rail 50 are removed by one. That is, by sequentially moving the first suspension device 20 while repeating the process of removing the rail 51 and the fixing member 52 one by one every time two existing floor slabs 13 are removed, the existing floor slab in the floor slab removal section N is moved. Remove all 13's.

Then, a new floor slab is installed on the main girder 12 of the floor slab removal section N from which all the existing floor slab 13 has been removed.

As described above, according to the deck removing method of the present embodiment, after cutting the existing deck 13 of the deck removing section N at a plurality of points in the bridge axis direction in the direction perpendicular to the bridge axis, the upper flange 12b of the main girder 12 The concrete between the and the existing deck 13 was cut by a predetermined length in the direction of the bridge axis, and the cut existing deck 13 was lifted and removed. The existing deck 13 can be removed with its full width without dividing it in the direction perpendicular to the bridge axis. That is, since it is not necessary to divide the existing floor slab 13 into a plurality of parts in the direction perpendicular to the bridge axis as in the conventional case, the number of divisions of the existing floor slab 13 to be removed can be significantly reduced. As a result, the existing floor slab 13 can be efficiently cut and removed, and the construction period can be shortened.

Further, since the concrete between the upper flange 12b of the main girder 12 and the existing floor slab 13 is cut with the wire saw 80 together with the stud 12d, the amount of concrete remaining on the main girder 12 can be extremely reduced. , The concrete removal work on the main girder 12 can be significantly reduced.

In this case, the drive device 81 of the wire saw 80 is arranged on another existing deck 13 arranged at another position in the bridge axis direction with respect to the existing deck 13 to be cut, and extends from the drive device 81. The wire saw 80 is passed through the lower surface side of the existing deck 13 through the through hole 13c drilled in the other existing deck 13, and the wire saw is placed on the end surface of the existing deck 13 to be cut on one end side in the bridge axis direction. 80 is hung from both sides of the upper flange 12b of the main girder 12 in the width direction, and the concrete (haunch 13b) between the existing deck 13 to be cut and the upper flange 12b of the main girder 12 is crossed in the bridge axis direction with a wire saw 80. The existing floor slab 13 and the main girder 12 to be cut can be reliably separated by the wire saw 80 extending from the drive device 81 arranged on the other existing floor slab 13. ..

Further, a second cutting step of cutting the concrete between the upper flange 12b of the main girder 12 and the existing deck 13 by a predetermined length L in the direction of the bridge axis, and lifting and removing the cut existing deck 13. Since the removal process is repeated from one end to the other end of the deck removal section N in the bridge axis direction, the first suspension device 20 and the transport trolley 40 are mounted on the existing deck 13 before being separated from the main girder 12. The work can be arranged and the work can be performed, and the floor slab removal work can be performed while moving the first suspension device 20 and the transport trolley 40 on the existing floor slab 13 along the rail 50. That is, if the space between all the existing floor slabs 13 and the main girder 12 in the floor slab removal section N is cut first, work cannot be performed on the unstable existing floor slab 13 separated from the main girder 12. However, in the present embodiment, the existing floor slab 13 before being separated from the main girder 12 can be used as a work place for the first suspension device 20.

Further, in the first cutting step, when the existing deck 13 is cut at a plurality of cutting positions C in the bridge axis direction at intervals L from each other, the concrete of the existing deck 13 is cut from the upper surface to a predetermined depth by a wet concrete cutter 70. After cutting to T1, the remaining concrete with a predetermined depth T2 was cut to the lower surface of the existing deck 13 with an anhydrous concrete cutter 71. It is possible to cut the concrete of the existing floor slab 13 at low cost while preventing the fall of sewage. That is, wet cutting requires treatment of the water used for cooling, but has the advantage of being cheaper than the dry type, while the dry type does not generate sewage, but is a large vacuum device for recovering cutting powder. Since the cost is high and the maximum depth is smaller than that of the wet type, most of the existing floor slab 13 in the thickness direction is cut by the wet type and the remaining small part is dry type as in the present embodiment. By cutting with, it is possible to reduce the cutting cost and take measures against sewage.

In this case, since the curing member 72 is attached to the lower surface of the existing floor slab 13 along the cutting position C, cutting powder is scattered below the bridge girder when the concrete is cut to the lower surface by dry cutting. There is no. Further, even if water or rainwater generated during the wet cutting in the previous step remains on the deck 134, the curing member 72 can prevent the water from falling below the bridge girder.

Further, the existing deck 13 of the deck removal section N is cut at a plurality of points in the bridge axis direction in the direction perpendicular to the bridge axis so that the length L in the bridge axis direction is shorter than the length W in the direction perpendicular to the bridge axis. Using a gate-shaped first suspension device 20 and a transport trolley 40 that can move on the deck 13 in the direction of the bridge axis, the cut existing deck 13 is lifted by the first suspension device 20, and the existing floor is lifted. The plate 13 is rotated so that the longitudinal direction is the bridge axis direction and mounted on the transport trolley 40, and the transport trolley 40 on which the existing floor slab 13 is mounted is transported to a predetermined transport location and the first suspension device. Since 20 is moved to the next deck removal position and the removal of the existing deck 13 is sequentially performed from one end to the other end in the bridge axis direction of the deck removal section N, the existing deck 13 is lifted by a crane car. It is not necessary, and the existing deck 13 to be removed can be transported in a direction smaller than the road width. As a result, the deck removal work can be performed without using a crane vehicle, so if there are sky restrictions due to crossing roads or high-voltage electric wires located above the construction site, or if there are adjacent roads or nearby structures in service. Even if there are restrictions on the work space in the road width direction, or if there are restrictions on the weight due to the load capacity of the existing bridge, the existing floor slab 13 can be removed without these restrictions.

In the above embodiment, each time a plurality (for example, two) of existing floor slabs 13 having a length L in the direction of the bridge axis are removed, one rail 51 having a length of 2 L and one fixing member 52 are removed. However, each time the existing floor slab 13 is removed, the rail 51 and the fixing member 52 having a length L may be removed one by one.

10 ... Bridge, 12 ... Main girder, 12d ... Stud, 13 ... Existing floor slab, 13c ... Through hole, 20 ... First suspension device, 30 ... Second suspension device, 40 ... Transport trolley, 50 ... Rail, 60 ... transport vehicle, 70, 71 ... concrete cutter, 80 ... wire saw, 81 ... drive device.

Claims (5)

In the method of removing the floor slab of a synthetic girder in which a concrete floor slab is installed on the main girder and the floor slab is removed from the synthetic girder in which the main girder and the floor slab are combined by a slip stopper provided on the upper surface of the main girder. ,
The first cutting step of cutting the deck in the deck removal section in the direction perpendicular to the bridge axis at multiple points in the bridge axis direction,
A second cutting step in which the concrete between the main girder and the floor slab is cut by a predetermined length in the bridge axis direction with a wire saw together with the slip prevention member.
Including the removal step of lifting and removing the floor slab cut in the second cutting step.
In the first cutting step, the concrete of the existing deck is cut from the upper surface to a predetermined depth by a wet concrete cutter, and then the remaining concrete is cut to the lower surface by a dry concrete cutter.
A method for removing a floor slab of a synthetic girder, which comprises repeating a second cutting step and a removal step from one end to the other end in the bridge axis direction of the floor slab removal section. In the second cutting step, the drive device of the wire saw is arranged on another deck arranged at another position in the bridge axial direction with respect to the deck to be cut, and the wire saw extends from the drive device. Is passed through the through hole drilled in another deck slab to the lower surface side of the deck, and the wire saw is hung from both sides in the width direction of the main girder to the deck to be cut, and the deck to be cut. The method for removing a deck of a synthetic girder according to claim 1, wherein the concrete between the main girder and the main girder is cut in the direction of the bridge axis with a wire saw. In the removal step, a gate-shaped suspension device and a transport trolley that can move in the direction of the bridge axis along the rail laid on the deck are used, and the deck cut in the second cutting step is lifted by the suspension device. The rail on the floor slab to be lifted and placed on the transport trolley, the transport trolley on which the deck is placed is transported to a predetermined location, the suspension device is moved by a predetermined distance in the direction of the bridge axis, and then the rail is to be removed. The method for removing a floor slab of a synthetic girder according to claim 1 or 2, wherein the method is to remove the rail. In the first cutting step, the deck is cut so that the length in the direction of the bridge axis is shorter than the length in the direction perpendicular to the bridge axis.
The floor of the synthetic girder according to claim 3, wherein the removing step is to rotate the deck lifted by the lifting device in the horizontal direction so that the longitudinal direction is the bridge axis direction and place it on the transport carriage. How to remove the plate. The method for removing a floor slab of a synthetic girder according to claim 3 or 4, wherein the floor slab is transshipped from a transport trolley to a transport vehicle using another gate-type suspension device arranged at the predetermined location. ..

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