JP2018031235A - Connection structure for steel girder bridge and connection method for existing steel girder bridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connection structure capable of making jointless an upper structure of a steel girder bridge comprising various main girder structures, and a connection method for an existing steel girder bridge.SOLUTION: As a connection structure for a steel girder bridge 1 in which multiple upper structures 2 and 3 comprising steel main girders 10 which are disposed at predetermined intervals in a bridge axis right-angle direction W, in a bridge axis direction L and steel cross-girders 20 disposed in the vicinity of ends of the steel main girders 10 in the bridge axis right-angle direction W, are disposed in the bridge axis direction L, in opposite portions of the upper structures 2 and 3 being adjacent in the bridge axis direction L, connection part concrete 31 provided between the steel cross-girders 20 and PC steel bars 32 connecting the steel cross-girders 20 with each other are provided. The PC steel bar 32 is disposed in an upper part of the steel main girder 10, and the connection part concrete 31 is provided at a position higher than a lower flange 11b of the steel main girder 10 by a predetermined height.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a steel girder bridge in which a plurality of superstructures having steel main girders in the bridge axis direction arranged at predetermined intervals in the direction perpendicular to the bridge axis are arranged in the bridge axis direction. The present invention relates to a connection structure to be made less and a connection method for existing steel girder bridges.

  Conventionally, in a steel girder bridge in which a plurality of upper structures having steel main girders in the bridge axis direction arranged at predetermined intervals in the bridge axis perpendicular direction are arranged in the bridge axis direction, the bridge axis direction While the ends of the steel main girders of the superstructure adjacent to each other have been provided with a telescopic device (joint) as shown in Patent Document 1 so far, the traveling performance is improved and the joint is caused by the joint. In order to improve vibration and noise, as shown in Patent Document 2, the main girder connecting method for connecting the web members of the steel main girder of the superstructure adjacent in the bridge axis direction is a jointless method (no joint Proposed as a chemical method).

  However, in the main girder connecting method as described above, the cross-sectional shape of the steel main girder in the superstructure adjacent in the bridge axis direction is different, or the position in the direction perpendicular to the bridge axis is different, that is, the string is aligned. If the number of digits of the steel main girder is different, it is difficult to connect the web members in the steel main girder, and there are many structures to which the main girder connection method cannot be applied.

JP-A-10-159023 JP 09-013319 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a connection structure capable of jointless upper structures of steel girder bridges having various main girder structures and a connection method for existing steel girder bridges.

  The present invention includes a steel main girder in a bridge axis direction arranged at a predetermined interval in a direction perpendicular to the bridge axis, and a steel cross girder in a direction perpendicular to the bridge axis arranged in the vicinity of the end of the steel main girder. A steel girder bridge connecting structure in which a plurality of upper structures provided in the direction of the bridge axis are arranged between the steel cross beams in a facing portion between the upper structures adjacent to each other in the bridge axis direction. And a connecting cross beam composed of a connecting portion concrete provided to the steel cross beams and connecting steel bars connecting the steel cross beams, and the connecting steel bars are arranged in the upper part of the connecting cross beams, The connecting cross beam is provided at a position higher than the lower end of the steel main beam by a predetermined height.

  Alternatively, according to the present invention, a steel main girder in a bridge axis direction arranged at a predetermined interval in a direction perpendicular to the bridge axis, and a steel cross girder in a direction perpendicular to the bridge axis in the vicinity of the end of the steel main girder. It is a connecting method of existing steel girder bridges in which a plurality of upper structures provided are arranged in the bridge axis direction, and the upper position in the steel main girder in the facing portion between the upper structures adjacent in the bridge axis direction The steel cross beam connecting step for connecting the steel cross beams with a connecting steel rod arranged in the concrete, and the concrete at a predetermined height higher than the lower end of the steel main beam between the steel cross beams And a concrete placing process for constructing a connecting portion concrete.

  The steel main girder described above can be a steel member formed in an I shape having flanges on the upper and lower ends of the web, a so-called I type steel, H type steel, or a steel box girder. It may be a steel main girder having a different shape or an upper structure composed of the same steel main girder, and the type of steel main girder may be different in the upper structure adjacent in the bridge axis direction. The same kind of steel main girder may be used.

  Even if the steel main girder is the same type, the steel main girder is composed of a steel member or steel box girder formed in an I shape, and a plurality of them are arranged in the direction perpendicular to the bridge axis. At least one of the cross-sectional shape, the axial direction, and the position of at least one of the steel main girders may be different in the superstructure adjacent to the bridge axial direction.

The difference in cross-sectional shape of the above-mentioned steel main girders means that the cross-sectional sizes of the steel main girders such as the girder height, girder width and plate thickness are different.
Moreover, that the axial directions of the steel main girders described above are different, the axial directions of any of the steel main girders are different from each other in at least one of a horizontal direction, a vertical direction, and an oblique direction. It means that the axial directions do not match, such as forming a square shape or inverted square shape in plan view or cross-sectional view, and more specifically, the crossing angle of each steel main beam in the axial direction is a predetermined angle or more. Say.

Moreover, that the position of the above-mentioned steel main girder is different means that the position of the opposing steel main girder is different in at least one of the horizontal direction, the vertical direction, and the diagonal direction. In addition, as a case where a position differs, the case where a position differs because the number of the steel main girders with which the upper structure was equipped differs, and the case where the steel main girders which oppose do not exist are also included.
The above-mentioned connecting steel bar includes any material as long as it is a connecting steel bar that resists a predetermined tensile axial force, such as a connecting steel bar made of PC steel including PC steel wire or a connecting steel bar made of rebar. Shall be.

  According to this invention, the steel main girders in the upper structure adjacent to the bridge axis direction are mechanically connected and integrated through the connecting portion concrete in the direction perpendicular to the bridge axis integrated with the steel cross beam. And the upper structures can be made jointless.

  More specifically, since a connecting portion concrete provided between the steel cross beams and a connecting steel rod for connecting the steel cross beams are provided, the steel cross beam and the connecting portion concrete are provided. An RC structure cross beam integrated with (1) can be formed. Moreover, axial force can be transmitted to the steel cross beams of the upper structure adjacent to the bridge axis direction by the connecting steel bars constituting the connecting cross beams of the RC structure. Therefore, the steel main girders in the upper structures adjacent to each other in the bridge axis direction can be mechanically connected and integrated.

  In addition, the connecting steel bar is disposed at the upper part of the connecting part concrete, and the connecting cross beam is provided at a position higher than the lower end of the steel main beam by a predetermined height. Since it becomes lower than the girder or steel girder height and the distance from the support location by the support device to the connecting part concrete can be secured, the deformation performance is improved and a flexible connecting structure can be constructed.

Therefore, an axial force in the tensile direction associated with the deflection deformation of the steel main girder acts on the connecting cross beam, and the tensile axial force is applied to the bending moment, so that the compressive force is reduced and the tensile force is increased. The increased tensile force can be resisted by the connecting steel rod, and the degree of compressive stress of the connecting concrete of the connecting cross beam can be reduced.
Thus, the connection structure of the present invention makes it possible to make the upper structure of the steel girder bridge having various main girder structures jointless.

  In addition, the above-mentioned steel main girders are mechanically connected and integrated to each other means a state in which a cross-sectional force (axial force) acting on the superstructure can be reliably transmitted, and at a predetermined interval in the direction perpendicular to the bridge axis. In addition to connecting and integrating each of the steel main girders arranged in plural with a steel main girder in the upper structure adjacent to the bridge axis direction, the upper main structure is provided with a connection. Including the integrated steel main girder as a whole.

As an aspect of the present invention, the connecting steel rod may be disposed inside the connecting portion concrete.
According to this invention, since the connecting steel bar is not exposed, a durable connecting cross beam can be configured. Further, since the connecting portion concrete, the steel cross beam and the connecting steel bar are integrated to form a connecting cross beam, the connecting steel bar can effectively resist the tensile axial force acting mainly.

Moreover, as an aspect of the present invention, a shear reinforcing bar in a direction perpendicular to the bridge axis with respect to the end portion of the steel main girder may be provided inside the connecting portion concrete.
The shear rebar in the direction perpendicular to the bridge axis with respect to the end portion of the steel main girder may be a shear rebar penetrating the end portion of the steel main girder in the direction perpendicular to the bridge axis. It may be a shear rebar in the direction perpendicular to the bridge axis that is stud welded to the end of the main girder.
According to the present invention, the acting axial force can be reliably transmitted to the steel main beam via the connecting cross beam.

As an aspect of the present invention, the connecting cross beam may be disposed above the center in the height direction of the steel main beam.
As for the connection cross beam arranged above the center in the height direction of the steel main beam, the whole connection cross beam may be arranged above the center in the height direction of the steel main beam, or the connection The main part of the cross beam may be arranged above the center in the height direction of the steel main beam. Specifically, if the neutral axis of the connecting cross beam is arranged above the center of the steel main beam in the height direction, a part of the height direction may be the center of the steel main beam in the height direction. The aspect extended below the center may be straddled.

  According to the present invention, a gap is formed below the connecting cross beam, that is, below the center in the height direction of the steel main girder, and the steel main girder is bent due to a live load acting on the upper structure. The restraint of deformation of the steel main girder by the connecting cross beam is reduced. That is, since the deformation of the steel main girder due to the live load is increased, the bending moment acting on the connecting cross beam is reduced. On the other hand, the axial force in the tensile direction acting on the connecting cross beam is increased.

  In particular, since the connecting cross beam arranged above the center in the height direction is arranged in a tensile region in the steel main beam, the axial force in the pulling direction mainly acting on the connecting cross beam. On the other hand, the connecting steel rods constituting the connecting cross beam mainly resist efficiently.

As an aspect of the present invention, one of the upper structures adjacent to the bridge axis direction may be supported by a fixed support device with respect to the lower structure, and the other may be supported by a movable support device.
According to the present invention, since a flexible connecting structure is constructed by the connecting cross beams, it is possible to allow movement in the movable support device due to the deflection of the steel main beam due to a live load.

  The fixed bearing device limits the movement of the steel main girder, while the movable bearing device does not limit the movement of the steel main girder. Can move. However, since the steel main girder is restricted in its free movement in the direction of the bridge axis by the connecting cross beam, the load generated by the restriction by the connecting cross beam is applied to the fixed support device via the connecting cross beam. Will act.

  Further, the load, that is, the reaction force of the axial force acting on the connecting cross beam is transmitted as a horizontal load to the lower structure on which the fixed support device is installed, and the lower structure is deformed. As described above, since a part of the deflection of the steel main girder is absorbed by the deformation of the lower structure, the cross-sectional force acting on the connecting cross girder can be reduced, and the member cross-section can be downsized.

  According to the present invention, it is possible to provide a connecting structure capable of jointless steel girder bridge superstructures having various main girder structures and a connecting method for existing steel girder bridges.

The perspective view of the steel girder bridge connected with the connection structure of this invention. The perspective view of the steel girder bridge connected with the connection structure of this invention. The perspective view of the steel girder bridge connected with the connection structure of this invention. Explanatory drawing of the steel girder bridge connected with the connection structure of this invention. The perspective view of the existing steel girder bridge of conventional structure. The flowchart of the connection construction method in the existing steel girder bridge. Explanatory drawing in the connection construction method in the existing steel girder bridge. Explanatory drawing in the connection construction method in the existing steel girder bridge. Explanatory drawing in the connection construction method in the existing steel girder bridge. Action | operation explanatory drawing of the steel girder bridge connected with the connection structure of this invention.

An embodiment of the present invention will be described in detail with reference to the drawings.
1 to 3 are perspective views of the steel girder bridge 1 connected with the connecting structure of the present invention, FIG. 4 is an explanatory view of the steel girder bridge 1 connected with the connecting structure of the present invention, and FIG. The perspective view of the steel girder bridge 1a is shown.

  Specifically, FIG. 2 illustrates the steel main girder 10 and the steel cross girder 20 in a transparent state, and FIG. 3 omits the illustration of the end-point-side upper structure 2 on the end-point side and the bridge of the connecting cross-girder 30. The internal structure on one side in the direction perpendicular to the axis W is illustrated. 4 (a) and 4 (b) are cross-sectional views taken along the line aa in FIG. 1, and FIG. 4 (b) illustrates the connecting cross beam 30 in a transparent state. Further, in FIGS. 1 to 3 and FIG. 5, illustration of the surface pavement 5 and the RC floor slab 4 is omitted.

  6 shows a flowchart of the connecting method in the existing steel girder bridge 1a, FIGS. 7 to 9 show explanatory diagrams in the connecting method in the existing steel girder bridge 1a, and FIG. 10 shows the steel connected by the connecting structure of the present invention. The action explanatory view of the girder bridge 1 is shown.

  Specifically, FIG. 7 to FIG. 9 illustrate each process by the aa sectional view in FIG. 1 or FIG. 5, and FIG. 7 (a) is an aa section of the existing steel girder bridge 1a before construction. 7 (b) shows a cross-sectional view taken along the line aa after completion of the web drilling, FIG. 8 (a) shows a cross-sectional view taken along the line aa after the assembly of the PC steel bar / rebar, and FIG. ) Shows an aa cross-sectional view of the existing steel girder bridge 1a after the telescopic device 7 is removed, FIG. 9 (a) shows an aa cross-sectional view after completion of concrete placement, and FIG. 9 (b) shows a pavement. The aa sectional drawing after completion is shown.

  The present invention relates to a steel main girder 10 in the bridge axis direction L arranged at a predetermined interval in the bridge axis perpendicular direction W, and a steel in the bridge axis perpendicular direction W arranged in the vicinity of the end of the steel main girder 10. In the steel girder bridge 1 in which the upper structures 2 and 3 provided with the cross beams 20 are arranged in the bridge axis direction L, the facing portions of the upper structures 2 and 3 adjacent to each other in the bridge axis direction L are connected to the cross beams 30. It is connected with a jointless (no joint).

More specifically, the steel girder bridge 1 includes a plurality of steel main girders 10 along the bridge axis direction L, and a steel cross girder in the direction perpendicular to the bridge axis W arranged near the ends of the steel main girder 10. 20 and an RC floor slab 4 disposed on the upper surface of the steel main girder 10, and a pavement portion 5 disposed on the upper surface of the RC floor slab 4 (the RC floor slab 4 and the pavement portion 5 in FIGS. 1 to 3 and FIG. 5). Are arranged in the bridge axis direction L and supported by a support device 60 arranged on the upper surface of the pier 6.
The upper structure on the starting side in the bridge axis direction L (upper right side in FIGS. 1 and 2) is the starting upper structure 3, and the upper structure on the end side (lower left in FIGS. 1 and 2) is the upper end side. The structure 2 is used.

  The steel main girder 10 is a steel member formed of a flange 11 arranged at an appropriate interval in the height direction and a web 12 in the height direction H that connects the flanges 11 to each other, and is formed in an I shape. Yes, a plurality of ribs 13 in the height direction H along the web 12 are arranged at predetermined intervals in the bridge axis direction L.

  The steel cross girder 20 is a steel member formed in an I shape, which is composed of a flange 21 and a web 22 and has a lower height than the steel main girder 10, and is adjacent to the direction W perpendicular to the bridge axis. It arrange | positions between the steel main beams 10, and is connected with the web 12 of the steel main beam 10, and is integrated structurally.

  The steel main girder 10 and the steel cross girder 20 are arranged on the bottom surface side of the RC floor slab 4 not shown in FIGS. 1 to 3 and 5 and are structurally integrated. A pavement 5 is provided and constitutes the upper structures 2 and 3. The RC floor slab 4 is an RC member having an appropriate thickness, and the pavement 5 is also an asphalt configured with an appropriate thickness.

  In addition, shapes, such as the number of the steel main girders 10 and the height of the steel main girders 10, are configured with an appropriate number and height that satisfy the required performance required for the upper structure. The end-point-side upper structure 2 on the end-point side in the bridge axis direction L is provided with three steel main girders 10, and the start-point-side upper structure 3 on the start-point side in the bridge axis direction L is composed of four steel owners. A digit 10 is arranged. That is, in the upper structures 2 and 3 adjacent to the bridge axis direction L, the steel main girders 10 on both sides of the bridge axis perpendicular direction W have the same axial direction in the bridge axis perpendicular direction W. The steel main girder 10 between W is shifted in the direction perpendicular to the bridge axis W in the axial direction.

  The upper structures 2 and 3 configured in this way are supported by a support device 60 disposed on the upper surface of the pier 6. Specifically, the end portion of the steel main girder 10 of the starting side upper structure 3 in the vicinity of the end of the bridge axis direction L is supported by the fixed support device 61, and the steel main girder 10 of the end side superstructure 2 is supported. The vicinity of the end portion on the starting point side in the bridge axis direction L is supported by the movable support device 62.

  The fixed support device 61 and the movable support device 62 are conventional support structures, and a detailed description of the structure is omitted and simplified, but the fixed support device 61 has a bridge axial direction L and The movement and lifting in the direction perpendicular to the bridge axis W are regulated and supported so as to be rotatable. The movable support device 62 regulates the movement and lifting in the direction perpendicular to the bridge axis W, is rotatable and has a predetermined amount of movement in the bridge axis direction L. It is supported so that it can move.

  The connecting cross beam 30 that connects the upper structures 2 and 3 configured as described above to be jointless is formed between the steel cross beams 20 facing each other in the bridge axis direction L and below the steel main beam 10. It is comprised by the connection part concrete 31 provided in the position higher predetermined height than the flange 11b, and the PC steel bar 32 (corresponding to a connection steel bar) which connects the steel cross beams 20 to each other.

  The connecting portion concrete 31 has an upper end that is flush with the upper flange 11a of the steel main girder 10 and has a height that is about ½ that of the steel main girder 10. Specifically, in this embodiment, the connecting portion concrete 31 is configured with a height of 800 mm with respect to the steel main girder 10 having a girder height of 1500 mm. Therefore, the connecting cross beam 30 is generally disposed above the center in the height direction H of the steel main beam 10, and a space is formed below the connecting cross beam 30. In addition, the connection cross beam 30 should just be comprised not only about 1/2 with respect to the height of the steel main beam 10 but 2/3 or less in height.

  Further, the connecting portion concrete 31 is wound around the ends of the web 12 in the steel main girder 10 so as to be bundled with the plurality of shear rebars 33 penetrating in the direction W perpendicular to the bridge axis and the plurality of shear rebars 33. This is a reinforced concrete structure in which shear reinforcing bars 34 arranged at a predetermined interval in the right-angle direction W are arranged and made of early-strength / expanded concrete.

  The shear reinforcing bars 33 are arranged through the through holes 35 drilled in the web 12, but are arranged in the bridge axis perpendicular direction W perpendicular to the web 12 of the steel main girder 10. If so, the bars may be arranged in a direction orthogonal to the web 12 by stud welding or the like without penetrating the web 12.

  Moreover, although the connection part concrete 31 may be comprised with normal concrete, even if it is not comprised with early-strength and expanded concrete, since the direction expresses with the early-strength and expanded concrete, strength is expressed early, It is more preferable when constructing the existing steel girder bridge 1a.

  The PC steel bar 32 corresponding to the connecting steel bar is a bar-shaped body made of PC steel material, and penetrates the through hole 23 which is perforated at an appropriate interval from the upper flange 21a in the web 22 of the steel cross beam 20. And arranged along the bridge axis direction L. Therefore, the PC steel bar 32 is in a mode of penetrating upward in the bridge axis direction L in the connecting portion concrete 31 disposed in the facing portion of the both steel cross beams 20.

  In this way, the steel girder bridge 1 that is jointless by connecting the opposing portions of the upper structures 2 and 3 adjacent to each other in the bridge axis direction L with the connecting cross beam 30 may be constructed as a new structure. The existing steel girder bridge 1a, which is composed of the same superstructures 2 and 3 and provided with the telescopic device 7, is removed from the telescopic device 7 and connected with a connecting cross beam 30 to make it jointless. The bridge 1 may be configured. A connecting method for connecting the existing steel girder bridge 1a with the connecting cross beam 30 to make it jointless will be described below.

  The joint method of making the existing steel girder bridge 1a having the telescopic device 7 jointless is to close the road first and then finally to the road so that even the existing steel girder bridge 1a in service is closed. Regulations can be minimized.

  Specifically, first, in order to construct the connecting cross beam 30 as a road construction, the web 22 and the appropriate portion of the flange 11 are perforated to form the through hole 23 and the through hole 35 (step s1: FIG. 7). (Refer to (b)), the PC steel rod 32 is disposed through both the through holes 23, and the shear reinforcing bar 33 and the shear reinforcing bar 34 that are penetrated through the through hole 35 are arranged and assembled (step s2: (See FIG. 8 (a)). This is the road construction.

  After the completion of the assembly of the PC steel bar 32 and the shear reinforcing bar 33 and the shear reinforcing bar 34, that is, after the completion of the road construction, as shown in FIG. 8B, the telescopic device 7 appearing on the pavement 5 is removed ( Step s3), early-strength / expanded concrete is placed on the road from which the expansion and contraction device 7 has been removed, and the connecting portion concrete 31 is constructed (step s4: see FIG. 9A).

  After the completion of the construction of the connecting part concrete 31, as shown in FIG. 9B, the floor slab part concrete 41 is placed between the connecting part concrete 31 and the RC floor slab 4 to restore the RC floor slab 4. Then, the place where the telescopic device 7 has been removed is paved (step s5), and the connecting method using the connecting cross beam 30 is completed. The girder bridge 1 can be configured. In addition, it is better to edge the floor slab concrete 41 and the connecting part concrete 31 between the floor slab concrete 41 and the connecting part concrete 31 with an edge cutting material (not shown) such as urethane or polystyrene foam.

In addition, after the connection part concrete 31 is hardened, the PC steel rod 32 may be tightened to prestress the connection cross beam 30.
Moreover, in the above-mentioned description, after removing the expansion and contraction device 7, as the construction on the road, concrete is placed from the road from which the expansion and contraction device 7 is removed, and the connecting portion concrete 31 is constructed (step s4). Prior to the removal of the expansion and contraction device 7 (step s3), as the road construction, the construction place of the connecting portion concrete 31 may be filled with concrete having a high self-filling property to constitute the connecting cross beam 30.

  As described above, the steel main girder 10 in the bridge axis direction L arranged at a predetermined interval in the direction perpendicular to the bridge axis W, and the steel in the bridge axis perpendicular direction W arranged in the vicinity of the end of the steel main girder 10. A connecting structure of steel girder bridges 1 (existing steel girder bridges 1a) in which a plurality of superstructures 2 and 3 each having a horizontal girder 20 are arranged in the bridge axis direction L, and is adjacent to the bridge axis direction L In the facing part between the objects 2 and 3, there is a connecting cross beam 30 constituted by a connecting portion concrete 31 provided between the steel cross beams 20 and a PC steel rod 32 connecting the steel cross beams 20. Since the PC steel bar 32 is provided at the upper part of the steel main girder 10 and the connecting cross girder 30 is provided at a predetermined height higher than the lower end of the steel main girder 10, the steel cross girder is provided. 20 is an upper structure adjacent to the bridge axis direction L via a connecting cross beam 30 in a direction W perpendicular to the bridge axis integrated with the bridge 20. The steel main beam 10 to each other in the 3 and integrated with mechanically linked and can be jointless the upper structure 2, 3 to each other.

  If it explains in full detail, since the connection crossing part 30 comprised by the connection part concrete 31 provided between steel cross beams 20 and the PC steel rod 32 which connects steel cross beams 20 will be provided. The steel cross beam 20, the connecting portion concrete 31, and the PC steel bar 32 can be integrated to form a connecting cross beam 30 having an RC structure.

  Also, the axial force can be transmitted to the steel cross beams 20 of the upper structures 2 and 3 adjacent to each other in the bridge axial direction L by the PC steel bars 32 constituting the connecting cross beams 30 of the RC structure. Therefore, the steel main beams 10 in the upper structures 2 and 3 adjacent to each other in the bridge axis direction L can be mechanically connected and integrated.

  Further, the PC steel bar 32 is arranged on the upper part of the steel main girder 10 and the connecting cross beam 30 is provided at a position higher than the lower end of the steel main girder 10 by a predetermined height. Since the height of the cross beam 20 and the steel main beam 10 is lower than that of the main beam 10 and the distance from the support location by the support device 60 to the connection cross beam 30 can be secured, the deformation performance is improved and a flexible connection structure is constructed. be able to.

For this reason, an axial force in the tensile direction accompanying the deflection deformation of the steel main beam 10 acts on the connecting cross beam 30, and a tensile axial force is applied to the bending moment, reducing the compressive force and increasing the tensile force. To do. The increased tensile force can be resisted by the PC steel bar 32, and the degree of compressive stress of the connecting portion concrete 31 of the connecting cross beam 30 can be reduced.
Thus, the connection structure of the present invention makes it possible to make the upper structures 2 and 3 of the steel girder bridge 1 (existing steel girder bridge 1a) having various main girder structures jointless.

  Moreover, since the PC steel bar 32 is disposed inside the connecting portion concrete 31, the PC steel bar 32 is not exposed, and therefore, a durable connecting cross beam 30 can be configured. In addition, since the connecting portion concrete 31 and the PC steel bar 32 are integrated to form the connecting cross beam 30, the PC steel bar 32 can efficiently resist the tensile axial force acting mainly.

  Moreover, since the shear rebar in the direction perpendicular to the bridge axis W with respect to the end portion of the steel main girder 10 is provided inside the connecting portion concrete 31, the acting axial force is reliably ensured via the connecting cross beam 30. It can be transmitted to the steel main beam 10.

  Moreover, since the connection cross beam 30 is arrange | positioned above the center of the steel main girder 10 in the height direction, there is a space below the connection part concrete 31, that is, below the center of the steel main girder 10 in the height direction. The deformation of the steel main beam 10 by the connecting cross beam 30 when the steel main beam 10 is bent due to the live load acting on the upper structures 2 and 3 is reduced. In other words, since the deformation of the steel main girder 10 due to the live load is increased, the bending moment acting on the connecting cross beam 30 is reduced, while the axial force in the tensile direction acting on the connecting cross beam 30 is increased. Become.

  In particular, since the connecting portion concrete 31 and the PC steel bar 32 disposed above the center in the height direction are disposed in the tensile region of the steel main girder 10, the connecting lateral portion constituted by the connecting portion concrete 31 is used. The PC steel rod 32 constituting the connecting cross beam 30 mainly effectively resists the axial force in the pulling direction that mainly acts on the beam 30.

  Of the upper structures 2 and 3 adjacent to each other in the bridge axis direction L, the starting-side upper structure 3 is supported by the fixed support device 61 with respect to the pier 6 and the end-point-side upper structure 2 is supported by the movable support device 62. Therefore, a flexible connection structure is constructed by the connection cross beam 30 and the movement in the movable support device 62 due to the bending of the steel main beam 10 due to a live load can be allowed.

  The fixed support device 61 restricts the movement of the steel main girder 10 of the starting side upper structure 3, while the movable support device 62 does not restrict the movement of the steel main girder 10 of the end side upper structure 2. It is possible to move on the movable bearing device 62 by the bending of the steel main beam 10. However, since the steel main girder 10 of the upper structure 2 on the end point side is restricted from freely moving in the bridge axis direction L by the connecting cross beam 30, the load generated by the restriction by the connecting cross beam 30 is the connecting cross beam 30. It acts on the fixed support device 61 via the.

  Furthermore, the load, that is, the reaction force of the axial force acting on the connecting cross beam 30 is transmitted as a horizontal load to the pier 6 on which the fixed support device 61 is installed, and the pier 6 is deformed. Thus, since a part of the bending of the steel main girder 10 is absorbed by the deformation of the bridge pier 6, the cross-sectional force acting on the connecting cross beam 30 can be reduced, and the member cross section of the connecting portion concrete 31 can be reduced in size. it can.

  Specifically, the connecting cross beam 30 generates a bending moment due to bending due to a live load acting on the steel main beam 10, but the cross section resisting this is reduced, that is, the height of the connecting cross beam 30 is reduced. By forming, it becomes a flexible structure which can give the deformation performance, reduce the generated bending moment, and resist the axial force acting mainly.

  When a live load is applied to the upper structures 2 and 3, the steel main girder 10 is bent, and the end of the steel main girder 10 kicks up, and at the same time, the steel main girder of the upper structure 2 on the end point side 10 is moved by the movable support device 62.

  When the height of the connecting part is high as in the main girder connection which is a conventional connecting structure, the connecting part becomes a rigid structure, so that a large bending moment is transmitted, and the end point side supported by the movable support device 62 The steel main girder 10 of the superstructure 2 does not move so much, and the deformation due to bending acts as a bending stress on the connecting portion.

  On the other hand, since the rigidity in the connection cross beam 30 is reduced by lowering the height of the connection cross beam 30, the steel main beam supported by the movable support device 62 as shown in FIG. When the movement amount of 10 increases and the movement amount of the steel main girder 10 increases, an axial force is generated in the connecting cross beam 30 and the bending moment is reduced.

  Specifically, a schematic diagram in which the connecting cross beam 30 formed between the steel cross beams 20 is a beam of a ramen structure, and the space between the connecting cross beam 30 and the support device 60 is a pillar of a ramen (FIG. 10B). 10), the deformation of the beam end due to the difference in rigidity and the generated force are compared. As shown in FIG. 10C, when the rigidity of the connecting portion is relatively high, the connecting portion (ramen beam portion) Therefore, the rotational deformation around the corner of the ramen is small, and the movement of the movable support device 62 is also small.

  On the other hand, when the rigidity of the connecting portion is relatively low, such as a connecting structure by the connecting cross beam 30 arranged at a position higher than the center of the steel main beam 10 in the height direction H, the connecting portion (ramen beam portion) ) Is large, the rotational deformation of the corners of the ramen is large, and the movement of the movable support device 62 is large (see FIG. 10D).

  However, in reality, the steel main girder 10 of the end-point-side upper structure 2 supported by the movable bearing device 62 does not extend indefinitely (the girder length becomes longer) due to bending, and the movement is limited. At this time, an axial force is generated that pulls the fixed support device 61 toward the end point side in the bridge axial direction L. This axial force acts on the connecting cross beam 30 as an internal force, and acts on the fixed support device 61 as a horizontal force as a reaction force. It will be.

  Thus, the connection structure by the connection cross beam 30 arrange | positioned in the position higher than the center of the height direction H of the steel main beam 10 is connected with respect to the main beam connection structure which is a structure which resists a moment in a connection part. The bending moment is reduced by reducing the rigidity of the portion, and the reduced bending moment is resisted by the horizontal resistance force of the fixed support device 61 and the axial force of the connecting cross beam 30.

Furthermore, in the connection structure by the connection cross beam 30, the force acting on the connection cross beam 30 is reduced by considering the deformation of the bridge pier 6 (bridge pier spring).
Specifically, as described above, the steel main girder 10 of the end-point-side upper structure 2 integrated with the steel main girder 10 of the start-side superstructure 3 at the connecting cross beam 30 is the movable support device 62. Therefore, the bending of the steel main girder 10 becomes a horizontal load and is transmitted to the pier 6.

  In this way, the bending of the steel main girder 10 is transmitted as a horizontal load, and the bridge pier 6 is deformed, that is, the horizontal moment is generated in the pier 6 so that the bending moment generated in the connecting cross beam 30 is relaxed, The generated stress of the support device 60 can be suppressed, and the member cross section can be made small like the connecting cross beam 30 configured with about half the height of the steel main beam 10.

In the correspondence between the configuration of the present invention and the embodiment, the superstructure of the present invention corresponds to the end-point-side superstructure 2, the start-point-side superstructure 3,
Similarly,
The connecting steel bar corresponds to the PC connecting steel bar 32,
The lower end of the steel main beam corresponds to the lower flange 11b of the steel main beam 10,
One of the upper structures corresponds to the starting-side upper structure 3,
The substructure corresponds to the pier 6,
The other of the superstructure corresponds to the end-side superstructure 2,
Although the steel cross beam connecting process corresponds to step s2 and the concrete placing process corresponds to step s4, the present invention is not limited to the configuration of the above-described embodiment, and the technical idea shown in the claims. And many embodiments can be obtained.

  For example, in the above description, the steel main girder 10 is a steel member formed in an I shape with the flange 11 and the web 12, but is a so-called I-shaped steel, H-shaped steel, or a steel box girder. Alternatively, it may be the upper structures 2 and 3 constituted by the steel main girders 10 of different types and shapes, or the steel main girders 10 in the upper structures 2 and 3 adjacent in the bridge axis direction L. May be different, or the same type of steel main beam 10 may be used.

  Moreover, although RC floor slab 4 was comprised with the RC member which has appropriate thickness, you may comprise with a steel floor slab. Further, instead of the PC steel rod 32 which is a rod-shaped body made of PC steel material, a reinforcing bar may be used as long as it can resist the axial force acting on the connecting cross beam 30.

  Furthermore, although the connection part concrete 31 was comprised between the steel cross beams 20 which oppose the bridge-axis direction L, for example, when the space | interval of the bridge-axis perpendicular direction W of the steel main beams 10 is wide, steel, etc. The connecting portion concrete 31 may also be provided on the back side of the cross beam 20 and may be integrated by the connecting portion concrete 31 and the PC steel rod 32 provided between the steel cross beams 20.

DESCRIPTION OF SYMBOLS 1 ... Steel girder bridge 1a ... Existing steel girder bridge 2 ... End side upper structure 3 ... Starting side upper structure 6 ... Pier 10 ... Steel main girder 11b ... Lower flange 20 ... Steel cross girder 31 ... Connection part concrete 32 ... PC steel bar 33 ... Shear rebar 61 ... Fixed bearing device 62 ... Moving bearing device L ... Bridge axis direction W ... Bridge axis perpendicular direction

Claims (6)

An upper portion having a steel main girder in the bridge axis direction arranged at a predetermined interval in the direction perpendicular to the bridge axis, and a steel cross girder in the direction perpendicular to the bridge axis arranged in the vicinity of the end of the steel main girder. A steel girder bridge connection structure in which a plurality of structures are arranged in the direction of the bridge axis,
In the facing part between the upper structures adjacent to each other in the bridge axis direction,
A connecting cross beam composed of a connecting portion concrete provided between the steel cross beams and a connecting steel rod connecting the steel cross beams is provided,
The connecting steel bar is arranged at the top of the connecting cross beam;
A connecting structure of steel girder bridges in which the connecting cross girder is provided at a position higher than a lower end of the steel main girder by a predetermined height. The connection structure of the steel girder bridge according to claim 1, wherein the connection steel bar is arranged inside the connection portion concrete. The connection structure of the steel girder bridge according to claim 1 or 2, wherein a shear rebar in the direction perpendicular to the bridge axis with respect to an end of the steel main girder is provided inside the connection part concrete. The said connection cross beam is the connection structure of the steel girder bridge in any one of the Claims 1 thru | or 3 arrange | positioned from the height direction center of the said steel main beam. 5. One of the upper structures adjacent to the bridge axis direction is supported by a fixed support device with respect to the lower structure, and the other is supported by a movable support device. Steel girder bridge connection structure. An upper structure comprising a steel main girder in a bridge axis direction arranged at a predetermined interval in a direction perpendicular to the bridge axis, and a steel cross girder in a direction perpendicular to the bridge axis in the vicinity of the end of the steel main girder. It is a connecting method of existing steel girder bridges arranged in the bridge axis direction,
In the facing portion between the upper structures adjacent to each other in the bridge axis direction, a steel cross beam connecting step of connecting the steel cross beams with a connecting steel rod arranged at an upper position in the steel main beam,
An existing steel girder bridge connecting method for performing a concrete placing step in which concrete is placed at a predetermined height higher than the lower end of the steel main girder between the steel transverse girders to construct a connecting portion concrete. .

Images