JP2006112086A - Structure of bridge and method for rebuilding bridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To bring about suitability for the rebuilding of a railway bridge, or the expansion of a space under the bridge or the widening of a road; to enable construction work for them to be performed under a live wire; to utilize a track girder and a supporting beam for temporary construction as construction girders in that case; to eliminate the irrationality of demolition or removal of them by utilizing them as structural members of a newly built bridge after the utilization of them; to achieve the rationalization of construction, the shortening of a construction period and a reduction in construction cost; to reduce the weight of the newly built bridge by simplifying a constitution; and to facilitate and reduce the securement of a girder production yard or an erection yard. <P>SOLUTION: This structure of the bridge comprises newly installed over-road girders 25 and 26 for the newly built bridge 43, and main girders 34 and 35 which are arranged outside the over-road girders 25 and 26. The structure of the bridge is equipped with girder materials 21 and 38 which are laid between the main girders 34 and 35 and which can support the over-road girders 25 and 26. The newly installed over-road girders 25 and 26 are utilized as a construction girder for the newly built bridge 43. Additionally, the girder materials 21 and 38 can be utilized as the supporting beam for the newly constructed over-road girders 25 and 26. After the utilization of them, they are left to constitute the newly built bridge 43. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is suitable for, for example, replacement of a railway bridge, expansion of a space under a bridge, or widening of a road. After use, it will be used as a structural member of a newly constructed bridge to eliminate the unreasonableness of dismantling and removal, streamline construction, shorten the construction period, reduce construction costs, and simplify the configuration. The present invention relates to a structure of a bridge and a method for replacing the bridge, which can reduce the weight of a new bridge, and can easily and reduce the securing of a girder manufacturing yard or a construction yard.

For example, when it becomes necessary to replace a railway bridge due to aging or an increase in transportation volume, it is often difficult to secure an alternative transportation route. There are many.
As a method of such replacement work, generally, temporary line construction, girder horizontal construction method, etc. are adopted. Among these, temporary line construction is to install a temporary track on the side of the current track, operate the detour by detouring the railroad vehicle, remove the current track, install a new bridge, and install the horizontal girder construction method. Manufactures a bridge girder on the side of the current line, removes the current line after the bridge girder is completed, and installs a new bridge horizontally.

  However, it is difficult to secure temporary land for construction of temporary lines, and the construction costs increase due to the rent and acquisition of the land. There is a problem that the construction cost increases due to the need for a horizontal installation facility.

On the other hand, as another method of the replacement work, there is a method of sequentially replacing the bridge girder and the pier while supporting the railway track using the construction girder and the temporary pier.
For example, as a method of replacing a brick-arch bridge with a concrete bridge, construct the construction girder in the span direction of the brick-arch bridge, support the railroad track, and leave the pier of the brick-arch bridge to replace the construction girder. Supporting, cutting and removing the existing bridge girder, constructing new piers, constructing temporary piers between the new piers, supporting the construction girders with these new and temporary piers, dismantling and removing existing piers At the same time, construct a new bridge girder, disassemble and remove the construction girder after the construction of the bridge girder, install the railroad track on the new bridge girder, disassemble and remove the temporary pier after the bridge is completed, and replace the railway bridge Some have been made (for example, see Patent Document 1).

  The span of the newly constructed pier of the railway bridge thus constructed is longer than the span of the existing pier of the brick arch bridge, so that the space under the bridge can be expanded and the road under the bridge can be widened. Since the strength of the construction girder is insufficient until the construction of the new bridge girder after cutting and removal, it is necessary to construct a temporary pier between the newly constructed piers, and there is an unreasonable increase in the construction period and the construction cost.

Therefore, while constructing the construction girder in the span direction of the brick arch bridge and supporting the railway track, supporting the construction girder leaving the existing pier of the brick arch bridge, cutting and removing the existing bridge girder part, A new pier is constructed, and the construction girder is supported by the new pier and the existing pier.
Next, the main girder was placed in the span direction on both sides of the railroad track, and the main girder was supported on the newly constructed pier, and a large number of horizontal girders were installed between the main girders, and the construction girder was supported by the horizontal girder. Later, the existing bridge piers were dismantled and removed, and the main girder, the horizontal girder, and the new pier were integrated into the concrete. After the bridge girder was formed, the construction girder was dismantled and removed to install the railroad track on the bridge girder. (For example, see Patent Document 1)

  However, the improved replacement method requires a work girder and its construction and removal work, as well as a large number of cross girders and its installation work, which is cumbersome, lengthening the construction period, increasing the construction cost, and increasing the weight of the bridge. In addition, the construction of the main girder, horizontal girder, and new pier is integrated by concreting, which contributes to a longer construction period and higher construction costs. On the other hand, the structure of the bridge is also in the middle of the main girder Since the new bridge piers are arranged, the space under the bridge is halved, and there is a problem that the expansion and the widening of the road under the bridge are restricted.

  On the other hand, as a method of increasing the span of the bridge girder, a plurality of main girders are joined in the width direction and these are connected by a horizontal cable to form a bridge girder, and the main girder is made of a concrete containing a steel frame. A plurality of girders are joined together in the length direction, and these are connected by a prestressed inner cable to suppress the girder height and reduce the weight of the bridge girder, thereby increasing the span. There is a girder bridge (see, for example, Patent Document 2).

  However, since the girder bridge is connected to a plurality of main girders through a large number of horizontal cables and inner and outer cables, the construction is cumbersome and the construction cost is increased, and the plurality of girder bridges joined in the length direction. The main girder is connected by a steel frame with an internal and external cable, so it is difficult to replace the bridge while securing the use of the bridge, and there are concerns about strength against bending moments. There was a problem limited to small girder bridges for low loads.

JP 2002-97608 A JP 2003-184029 A

  The present invention solves such a problem, and is suitable for, for example, replacement of a railway bridge or expansion of a space under a bridge or widening of a road. Use the current beam as a construction girder and use it as a structural member for the newly constructed bridge to eliminate the unreasonableness of dismantling / removing them, streamlining construction, shortening the construction period, and reducing construction costs. In addition, a structure of a bridge and a method of replacing the bridge are provided, which simplifies the configuration to reduce the weight of a newly-built bridge, and further facilitates and reduces the securing of a girder manufacturing yard or an erection yard. With the goal.

The invention of claim 1 is a newly installed girder of a new bridge, a main girder arranged outside the girder, and a girder constructed between the main girder and capable of supporting the girder. In the structure of the bridge with, the newly constructed girder can be used as a construction girder for the newly constructed bridge, and the girder material can be used as a receiving beam for the newly constructed girder. Bridges are constructed to eliminate the unreasonableness of dismantling and removal after their use, and to make effective use of them, shortening the construction period and reducing construction costs.
According to the second aspect of the present invention, a pair of left and right newly installed road girders are connected via a connecting joint to form a new road, thereby facilitating the assembly of the new road and reducing its size and weight. ing.
According to a third aspect of the present invention, the newly constructed road girder is mounted on a girder, and the configuration is simplified by eliminating the interposition of components between them, thereby reducing the size and weight of the bridge.

The invention of claim 4 supports the end of the newly installed road girder in the span direction with the girder, connects the girder and the main girder, and makes the main girder longer than the newly installed girder. It is formed into a scale, and the main girder is supported at the outermost end in the span direction to reduce the number of girders used, reduce the labor of installation, shorten the construction period, reduce the construction cost, and reduce the weight. In addition to reducing the number of temporary piers used to install girders and the time and effort of installing them, the abutment or pier span under the main girder is expanded accordingly, and the use of the space is promoted. It is adapted to the widening of the roads below.
According to the invention of claim 5, the girder material and the main girder are constituted by PC girder or RC girder, and these are made robust and inexpensive.
The invention of claim 6 uses the newly installed road girder as a track girder, lays a rail directly on the newly installed road girder, omits the laying of sleepers, and shortens the work period and reduces the construction cost. At the same time, the new bridge will be lightened.

  In the invention of claim 7, after the temporary bridge pier is erected along the existing structure, a new road girder is constructed, and after the new road girder is supported by the temporary bridge pier, the existing structure is dismantled. Removed, installed abutments or piers along the newly constructed girder, installed a main girder between them, and supported the newly constructed girder on the main girder, then dismantled the temporary pier In the method of replacing the bridge to be removed, the temporary bridge pier is erected at the end of the new road girder, the new road girder is supported by the girder built on the temporary bridge pier, and the girder is used as a receiving beam. The new bridge girder is used as a construction girder for the new bridge, and after that, the new girder girder is used as the construction girder for the new bridge. To reduce the amount of time and effort required for erection work, and to make rational use of newly constructed road girders and girders. While shortening the construction period and reducing construction costs, the temporary bridge piers in the construction section are removed to promote the expansion of the space after removal and its effective use, for example, to respond to the widening of the road under the new bridge, etc. I have to.

  In the invention of claim 8, after the existing structure is removed, an abutment or a pier is erected outside the newly installed girder and at both ends of the construction section, and the main girder is installed between the abutment or the pier After connecting both ends of the girder to the main girder and supporting the newly installed girder to the main girder, dismantle and remove the temporary piers in the construction section to reduce the number of standing abutments or piers In addition to reducing the work required for the installation work, the construction period is shortened and the construction cost is reduced, and the temporary bridge piers in the construction section are dismantled and removed to promote the expansion and effective use of the space after removal. The range of use of the space is expanded so that, for example, it can respond to the widening of the road under the new bridge.

In the invention of claim 9, two girder members are erected on a single temporary bridge pier, and the end of a new road girder adjacent to the girder member is supported to reduce the number of erected piers. The effort of installation work is reduced to shorten the construction period and reduce the construction cost.
According to the invention of claim 10, after the existing structure is removed, the removal space is used for a girder production yard or a girder erection yard, and a girder production yard at a construction site. In addition to facilitating the securing of the door or the erection yard, the construction cost is reduced, and the production and erection of the main girder and the like are promoted at the construction site.

The invention of claim 1 makes it possible to use a newly constructed girder as a construction girder for a newly built bridge and the girder material as a receiving beam for a newly constructed road, and to construct a newly constructed bridge by leaving them after use. Therefore, it is possible to eliminate the unreasonableness of dismantling / removal after use and to make effective use thereof, thereby shortening the construction period and reducing the construction cost.
In the invention of claim 2, since the pair of left and right newly installed road girders are connected via a coupling joint to constitute the newly installed road, it is possible to facilitate the assembly of the newly installed road and to reduce the size and weight thereof. .
In the invention of claim 3, since the newly installed road girder is mounted on the girder, it is possible to simplify the configuration by eliminating the interposition of the constituent members therebetween, and to reduce the size and weight of the bridge.

The invention of claim 4 supports the end of the newly installed road girder in the span direction with the girder, connects the girder and the main girder, and makes the main girder longer than the newly installed girder. Since it is formed into a scale and the main girder is supported at the outermost end in the span direction, the number of girder materials used is reduced, the labor of installation is reduced, the construction period is shortened, the construction cost is reduced, and the weight is reduced. In addition to reducing the number of temporary piers used to install girders and the time and effort of installing them, the abutment or pier span under the main girder is expanded accordingly, and the use of the space is promoted. There is an effect corresponding to the widening of the road below.
In the invention of claim 5, since the girder and the main girder are constituted by PC girder or RC girder, these can be manufactured robustly and inexpensively.
In the invention of claim 6, since the newly installed road girder is a track girder and a rail is laid directly on the newly installed road girder, the laying of sleepers is omitted, and the construction period is shortened and the construction cost is reduced. It is possible to reduce the weight of the new bridge.

  The invention of claim 7 erected a temporary pier at the end of a newly installed girder, supported the newly installed girder on a girder constructed on the temporary pier, and used the girder as a receiving beam. After being used, it is left as a component of a new bridge, and the new road girder is used as a construction girder for a new bridge, and after it is used, it is left as a component of a new bridge. In addition to reducing the time and labor required for erection work, rational use of newly constructed road girders and girders is aimed at shortening the construction period and reducing construction costs, while at the same time removing the temporary piers in the construction section. For example, there is an effect that it can respond to the widening of the road under the new bridge.

  According to the invention of claim 8, after the existing structure is removed, an abutment or a pier is erected outside the newly installed girder and at both ends of the construction section, and the main girder is installed between the abutment or the pier After connecting both ends of the girder to the main girder and supporting the newly constructed girder to the main girder, the temporary piers in the construction section are disassembled and removed, so the number of standing abutments or piers is reduced. In addition to reducing the time and effort of the installation work, the construction period is shortened and the construction cost is reduced, and the temporary piers in the construction section are dismantled and removed, so that the space after removal can be expanded and effectively used. This has the effect of expanding the range of use of the space and responding to the widening of the road under the new bridge, for example.

In the invention of claim 9, since two girder members are erected on a single temporary pier and the end of a newly installed girder adjacent to the girder is supported, the number of erected piers is reduced, It can reduce the time and labor required for the erection work, shorten the construction period and reduce the construction cost.
In the invention of claim 10, since the existing structure is removed, the removal space is used for a girder manufacturing yard or a girder erection yard. -It is possible to easily secure the door or the erection yard, reduce the construction cost, and promote the production and erection of the main girder and the like at the construction site.

Hereinafter, the illustrated embodiment in which the present invention is applied to the replacement of a railway viaduct as a ground structure and the widening of a road under the viaduct will be described. FIGS. 1 to 3 show the situation of the viaduct before construction of the present invention. Show.
In FIG. 1, reference numeral 1 denotes an existing railway bridge which is a ground structure, and the bridge 1 is installed on a plurality of existing piers 3 standing on the ground 2 in a pair of left and right sides, and at the upper end of the pier 3. A horizontal girder 4, a bridge girder 5 connecting the adjacent cross beams 4, and a floor slab 6 which is an existing road girder made of RC, that is, made of reinforced concrete, supported on the cross beam 4, A track 7, which is an existing overhead road, is laid on the floor slab 6.

As shown in FIG. 3, the existing track 7 includes a roadbed 8 that swells crushed stone and gravel, a sleeper 9 disposed on the roadbed 8, and a rail 11 that is attached to the sleeper 9 via a fastener 10. It consists of and.
The distance between the piers 3a, 3a in the middle part of the bridge 1 is slightly wider than the distance between the other piers 3, and the latching pieces 12, 12 project from the lateral beams 4, 4, and the An existing bridge girder 13 is installed between the pieces 12 and 12.
In the figure, reference numeral 14 denotes a roadway formed on the ground 2 between the piers 3a, 3a, and sidewalks 16 are provided on both sides of the roadway via protective materials 15 such as guard rails.

4 and 5 show the completion status of the viaduct constructed according to the present invention, and FIGS. 6 to 15 show the construction procedure of the newly installed road girder and the new bridge 43 used in the present invention.
The replacement of the new bridge 43 according to the present invention is carried out while ensuring the live state of the railway, which is the removal of the existing track 7 in the construction section Z approximately four times wider than the piers 3a, 3a, This includes the replacement of the new bridge 43 and the widening of the road 14.
When removing the existing track 7 in the construction section Z, first, the pile 17 is driven between the existing piers 3 and 3, and the temporary pier 18 framing the steel frame is erected on the pile 17. The temporary support column 20 is erected on the foundation anchor 19 embedded in the section.

On the other hand, before and after the temporary pier 18 and the temporary support 20 are erected, through holes (not shown) are formed at the corresponding positions of the floor slab 6 located immediately above them, and the temporary piers 18 and the temporary piers 18 are provided in the respective through holes. Insert the upper end of the support column 20 and project the upper end of the column 20 onto the floor slab 6, and support beams 21 and 22, which are girders made of PC or steel, are installed at the same height on the upper end. Yes.
Among these, the length of the receiving beam 21 made of PC is formed longer than the width of the new road girder described later, and both ends of the receiving beam 21 protrude outside the road girder, and the receiving beam 21 is projected to the protruding end. The bar arrangement (not shown) is exposed (see FIG. 9), and the steel beam receiving beam 22 is removed together with the temporary support 20 after the bridge 1 is replaced. In the figure, reference numeral 23 denotes a steel frame frame constructed on the upper end of the temporary pier 18.

Under such circumstances, the sleepers 9 and the fastening devices 11 of the existing track 7 on the floor slab 6 are removed, and the central part of the roadbed 8 of the sleeper traces is excavated through heavy equipment (not shown), and the excavation is performed. The road girders 25 and 26 which are track girders are accommodated facing each other in the hole 24 and supported by the receiving beams 21 and 22.
As shown in FIG. 6, the road girders 25 and 26 are formed of a pair of left and right PC girders having a substantially L-shaped cross section, that is, rebar concrete to which prestress is applied by a PC steel material 27. The rail 11 is directly laid and the sleepers 9 are omitted.
In the embodiment, the plurality of road girders 25 and 26 are connected and laid over the construction section Z, but this may be configured as a single unit, and by doing so, the labor of connection is reduced. Is reduced.

The road girders 25 and 26 are opposed to each other with a slight gap, and a plurality of coupling joints 28 are arranged at equal intervals between the opposed end faces.
As shown in FIG. 6, the connecting joint 28 is formed in a substantially box shape by welding side plates 29 on both sides of the I-shaped steel, and through holes (not shown) into which the PC steel material 30 can be inserted are formed in the side plates 29. One end of the PC steel materials 30 and 30 is hooked on the side plate 29, and the other end is arranged at the outer end of the road girders 25 and 26. A nut (not shown) is screwed into the threaded portion and tightened. The road beams 25 and 26 are connected.

After laying the rail 11 on the road girders 25 and 26, the remaining gravel on the floor slab 6 in the construction zone Z is removed, and the pier 3, the floor slab 6 and the bridge girder 5 constituting the existing structure are dismantled and removed. The girder production yard or the girder construction yard is secured around the temporary bridge pier 18, and the main girder 34, 35 is produced and erected.
The pile 31 is driven into the ground 2 on the inner side of the temporary support columns 20 and 20 before and after the installation of the road girders 25 and 26, or after the floor slab 6 and the bridge girder 5 are disassembled and removed.
A foundation anchor 32 is constructed on the pile 31, and abutments 33 and 33 are erected on the anchor 32, and the upper end portions thereof are positioned directly below the front and rear end portions of the road girders 25 and 26. A pair of left and right PC main girders 34 and 35 are supported.

The main girders 34 and 35 are formed in a substantially vertically long rectangular cross section, the length of which is substantially three times that of the road girders 25 and 26, and the length of the span between the abutments 33 and 33 is substantially the same. Grooves 34a and 35a are formed in the middle part of the side surface.
The girder height H of the main girders 34 and 35 is formed to be approximately three times the girder height of the road girders 25 and 26 to increase the rigidity thereof, and the upper end thereof is substantially the same as the upper ends of the road girders 25 and 26. Located at the same height

At the front and rear end portions of the main girders 34 and 35, the PC receiving beam 21 and the cross beam 38 which is a beam member, opposed rectangular beams 36 and 37 are formed. In FIG. 37, bar arrangements (not shown) of the main 34 and 35 are shown vertically and horizontally.
Then, in the reinforcing bars (not shown) of the connection windows 36 and 37, the reinforcing bars (see FIG. 9) exposed at the end of the receiving beam 21 and the reinforcing bars (shown in FIG. 9) exposed at both ends of the lateral beam 38 are shown. The PC receiving beam 21 and the cross beam 38 are connected between the main girders 34 and 35 by engaging the connecting windows 36 and 37 with concrete.

The connection situation in this case is as shown in FIG. 10 and FIG. 11 and is an upper road structure in which the overhead girders 25 and 26 constituting the newly installed track are located above the main girders 34 and 35. It is also possible to adopt a downway structure.
In the figure, 39 is a buffer plate interposed between the road beams 25 and 26 and the receiving beam 21 and the horizontal beam 38, and 40 is a buffer plate interposed between the horizontal beam 38 and the abutment 33.

Thus, when the receiving beam 21 and the transverse beam 38 are connected to the main girders 34 and 35 and the load of the main girders 34 and 35 is transferred to the abutment 33, the temporary pier 18, the temporary support 20 and the frame 23 of the construction section are Is dismantled and removed, and the space 41 under the bridge just below the main girders 34 and 35 is opened and expanded.
In the embodiment, the distance between the piers 3a and 3a is expanded to about four times the space 41, the space 41 is allocated to the road space, and the two-lane roadway 14 and the sidewalk 16 are constructed in the space. .
In addition, in the figure, 42 is a railway vehicle or a building limit, and 43 is a new bridge.
In this embodiment, the bridge 1 is adopted as the ground structure. However, the present invention is applied to an existing structure in which embankment (not shown) is adopted instead of the bridge 1 and the track 7 is laid on the embankment. It is also possible to do.

When the newly constructed bridge 43 is actually replaced by the bridge replacement method of the present invention configured as described above, the construction is performed while securing the live line state of the railway.
The construction method includes the removal of the existing track 7 in the construction section Z, the replacement of the new bridge 43 in the section Z, and the widening of the road 14 in the space 41 under the bridge.
First, when the existing track 7 in the construction section Z is removed, the pile 17 is driven between the existing piers 3 and 3, and the temporary piers 18 that frame the steel frame are erected on the pile 17. The temporary support column 20 is erected on the foundation anchor 19 embedded in the section.

On the other hand, a predetermined through hole (not shown) is formed at a corresponding position of the floor slab 6 located immediately above the temporary bridge pier 18 and the temporary support column 20 upright, and the temporary pier 18 is formed in each through hole. The frame 23 and the upper end portion of the temporary support column 20 are inserted, and these are projected on the floor slab 6.
And, from the upper part of the floor slab 6 to the upper end of them, PC or mold steel receiving beams 21 and 22 are installed at the same height position as construction girders. Prepare for 42 runs.

  The length of the receiving beam 21 made of PC is longer than the width of the road girders 25 and 26, and the bar arrangement of the receiving beam 21 is exposed at the end as shown in FIG. As described above, the receiving bridge 22 is removed together with the temporary support column 20 after the new bridge 43 is replaced.

  In this case, since the receiving beams 21 and 22 are disposed at both ends of the road girders 25 and 26 and are not disposed at the intermediate portion, the receiving beams 21 are compared with the conventional method of installing a large number of receiving beams. The number and installation effort and weight are reduced, and the adjacent pair of receiving beams 21 are supported by the temporary bridge piers 18, so that the number of temporary piers 18 and the installation effort thereof are reduced. As a result, the span of 18 and 18 is widened, so that it becomes easy to secure a girder manufacturing yard described later.

  Under these circumstances, when the existing track 7 is to be removed, the sleepers 9 and the fastening devices 11 of the existing track 7 on the floor slab 6 are removed, and the central portion of the road bed 8 after the sleepers 9 are removed is heavy equipment. Cutting (not shown) is performed, and the road girders 25 and 26 are individually accommodated in the excavation hole 24 by using a heavy machine, and these are opposed to each other and supported by the receiving beams 21 and 22. This situation is as shown in FIG.

As shown in FIG. 6, the overhead girder 25, 26 is composed of a pair of left and right PC girder having a substantially L-shaped cross section, and the rail 11 is provided in the step girder 25a, 26a. Laying directly through the fastening device 10.
This situation is as shown in FIG. 8, and in the embodiment, a plurality of road girders 25 and 26 are connected and laid over the construction section Z, but this may be configured as a single unit, By doing so, the time and effort of connection is reduced.

The road girders 25 and 26 are opposed to each other with a slight distance therebetween, and a plurality of connecting joints 28 are arranged at equal intervals between the opposed end faces.
As shown in FIG. 6, the connecting joint 28 is formed in a substantially box shape by welding side plates 29 on both sides of the I-shaped steel, and through holes (not shown) through which the PC steel material 30 can be inserted are formed in the side plates 29. One end of the PC steel materials 30 and 30 is hooked on the side plate 29 and the other end is arranged at the outer end of the road girder 25 and 26. A nut (not shown) is screwed into the screw portion and tightened. , The road girders 25 and 26 are connected.

Thus, the rail 11 is laid on the road girders 25 and 26, and these are transferred to the receiving beams 21 and 22, and then the gravel, crushed stones and the like of the road bed 8 on the floor slab 6 are removed, and the existing structure located in the construction section Z After dismantling and removing the floor slab 6, bridge girder 5, pier 3, and (filling if there is embankment), secure a girder manufacturing yard or its construction yard around the temporary pier 18 In this case, when the yarn cannot be secured at the construction site, the main girders 34 and 35 are produced at the close position or at a factory or the like and transported to the construction site.

Then, the pile 31 is driven into the ground 2 on the inner side of the temporary support columns 20 and 20 after the construction of the road girders 25 and 26, or after the floor slab 6 and the bridge girder 5 are disassembled and removed.
A foundation anchor 32 is constructed on the pile 31, and abutments 33 and 33 are erected on the anchor 32, and the upper end portions thereof are positioned directly below the front and rear end portions of the road girders 25 and 26. A pair of left and right PC main girders 34 and 35 are supported.

After the main girders 34 and 35 are produced by the girder production yarn, they are lifted or jacked up by heavy machinery at the installation yard and positioned at the outer ends of the receiving beam 21 and the horizontal girder 38. This situation is as shown in FIG.
The main girders 34 and 35 are formed in a substantially vertically long rectangular cross section, and concave grooves 34a and 35a are formed on the outer surface of the intermediate portion thereof. The girder height H is formed to be approximately three times the girder height of the road girders 25 and 26. In addition to increasing the rigidity thereof, the length thereof is approximately three times the length of the bridge girders 25 and 26, and is formed to be approximately the same length as the span between the abutments 33 and 33, and the upper end thereof is formed on the road girders 25 and 26. 26 is arranged at substantially the same height as the upper end of 26.

  The main girders 34 and 35 are formed with substantially rectangular connecting windows 36 and 37 at positions opposite to the front and rear ends thereof and the receiving beam 21, and the reinforcing bars of the main girders 34 and 35 are arranged in these connecting windows 36 and 37. (Not shown) is exposed vertically and horizontally, while reinforcing bars are exposed at both ends of the receiving beam 21 and the horizontal beam 38.

  Therefore, when the receiving beam 21 and the horizontal beam 38 are connected to the main girders 34 and 35, the reinforcing bars (not shown) of the connecting windows 36 and 37 are arranged at the end of the receiving beam 21 (FIG. 9). And a bar arrangement (not shown) exposed at both ends of the cross beam 38, and a concrete is placed in each of the connecting windows 36 and 37 to connect them together.

  The connection state is as shown in FIG. 10 and FIG. 11 and is an upper road structure in which the road girders 25 and 26 constituting the track 7 are positioned above the main girders 34 and 35, but depending on the construction conditions, the middle road or the lower road It is also possible to adopt a structure.

In this way, the receiving beam 21 and the lateral beam 38 are connected to the main girders 34 and 35, and when the loads of the main girders 34 and 35 are transferred to the abutment 33, the temporary pier 18, the temporary support 20 and the frame 23 in the construction zone Z are obtained. Are disassembled and removed, and the space 41 under the bridge just below the main girders 34 and 35 is opened and expanded.
In this case, in the embodiment, both ends of the main girders 34 and 35 are supported by the abutment 33, and no bridge pier or abutment is arranged in the middle thereof, so that the space 41 below the bridge is effectively expanded correspondingly.
In the embodiment, the space 41 under the bridge is expanded to about four times the distance between the piers 3a and 3a before the replacement, and the space 41 is allocated to the road space, and the space is added to the space. A lane road 14 and a sidewalk 16 are constructed.

  As described above, the bridge replacement according to the present invention is performed by replacing the existing bridge 1 with the bridge girder 25, 26, the receiving beam 21, the cross beam 38, and the main girder 34, 35 with the rail 11 remaining at the current position. Since it has been replaced with a new bridge composed of, etc., it is possible to secure the operation of the railway vehicle 42 at the time of construction without adopting the conventional temporary line construction and girder horizontal construction method. It is not necessary to secure a temporary line site in the construction method, and to secure a large girder manufacturing and construction yard, so that the construction cost can be increased and the equipment cost can be reduced.

  In addition, since the road girders 25 and 26, which are track girders, are used as temporary construction girders, the construction can be carried out rationally and inexpensively without the need for new construction girders. Because it is used as a component, it does not require dismantling / removal after replacement, unlike conventional construction girders, thereby shortening the construction period and reducing construction costs.

  The newly constructed bridge 43 thus replaced is composed of the road girders 25 and 26 constituting the roadway, the receiving beam 21 and the horizontal girder 38, the main girders 34 and 35, and the abutment 33, and the main girder 34, The spans 21 and 22 and the cross girder 38 are installed at the ends in the span direction of 35, and these are integrally connected, and only the outermost end in the span direction of the main girders 34 and 35 is connected to the abutment 33 or the pier. Supporting

Accordingly, the number of receiving beams 21 and 22 and the horizontal beams 38, which are girders, can be reduced, the labor of installation can be reduced, the construction period can be shortened, the construction cost can be reduced, and the weight can be reduced. The number of temporary piers 18 to be installed and the labor of installing them are reduced, and the abutment 33 or pier span under the main girder is expanded to expand the range of use of the space, for example, the road under the main girder. It can be adapted to widening such as.
In the above-described embodiment, the receiving beams 21 and 22 and the main girders 34 and 35 are configured by PC girders and are connected as described above. However, the receiving beams 21 and 22 and the main girders 34 and 35 are connected to each other. It is also possible to configure the RC girder and connect them using a connecting bracket and bolts / nuts.

  As described above, the structure of the bridge of the present invention and the method of replacing the bridge, for example, can be performed under a live line, and the track girder or the temporary receiving beam is used as the construction girder. It is used as a member to eliminate the unreasonableness of dismantling and removal, streamline construction, shorten construction period and reduce construction costs, simplify the structure and reduce the weight of the new bridge, and manufacture girders Since the securing of the yard or the erection yard can be easily and reduced, it is suitable for, for example, replacement of a railway bridge, expansion of a space under the bridge, or widening of a road.

It is a front view which shows the condition of the existing bridge before construction of this invention. In the plan view of FIG. 1, it is shown slightly enlarged. It is sectional drawing which shows the principal part of the track | orbit before construction of this invention. It is a front view which shows the condition of the new bridge which constructed this invention. In the plan view of FIG. 4, it is shown slightly enlarged. It is a perspective view which shows the assembly state of the road girder applied to this invention.

It is sectional drawing which shows the construction state by this invention, and has shown the condition where the existing track was removed, the receiving beam was laid in the same position, and the road girder of the new track was installed. In sectional drawing which shows the construction state by this invention, the existing track is removed, the receiving beam is laid in the same position, and the state where the rail is laid is shown after installing the road girder of the new track. In the sectional view showing the construction state according to the present invention, the existing track is removed, the receiving beam is installed at the same position, the road girder of the new track is installed, the rail is installed, and the main beam is connected to the receiving beam. Indicates the situation. It is an expanded sectional view which follows the AA line of FIG.

It is an expanded sectional view which follows the BB line of FIG. It is a fragmentary sectional view which follows the CC line of FIG. It is the front view which shows the construction state by this invention, and has shown the condition where several temporary bridge piers are erected in the construction section, the existing bridge is removed, and the bridge girder of the new bridge is laid. In the front view showing the construction state according to the present invention, a plurality of temporary piers are erected in the construction section, the existing bridge is removed, and the bridge girder of the new bridge is laid, and then the temporary support column and the abutment are erected. Indicates the situation. In the front view showing the construction state according to the present invention, a plurality of temporary piers are erected in the construction section, the existing bridges are removed, and the bridge girder of the new bridge is laid, then the temporary columns and abutments are erected, It shows the situation where the main girder is installed between them.

Explanation of symbols

1 Ground structure (existing bridge)
3 Existing pier 5 Existing bridge girder 6 Existing road girder (floor)
7 Existing roadway (track)
11 Rail 21 Girder (receiving beam)
25, 26 Newly installed girder 28 Connection joint 33 Abutment 34, 35 Main girder 38 Girder material (horizontal girder)
43 New Bridge Z Construction Section

Claims (10)

  A bridge structure comprising a newly installed road girder of a new bridge, a main girder arranged outside the road girder, and a girder constructed between the main girder and capable of supporting the road girder The new bridge girder can be used as a construction girder for the new bridge girder, and the girder material can be used as a receiving girder for the new road girder, and the new bridge girder can be left behind to form a new bridge. Bridge structure.   The bridge structure according to claim 1, wherein a pair of left and right newly installed road girders are connected via a connecting joint to form a new road.   The bridge structure according to claim 1, wherein the newly installed road girder is mounted on a girder.   The end of the new road girder in the span direction is supported by the girder, the girder and the main girder are connected, and the main girder is formed longer than the new road girder. The bridge structure according to claim 1, wherein the girder is supported at the outermost end portion in the span direction.   The bridge structure according to claim 1, wherein the girder and the main girder are PC girder or RC girder.   The bridge structure according to claim 1, wherein the new road girder is a track girder, and a rail is directly laid on the new road girder.   After the temporary bridge pier is erected along the existing structure, a new road girder is constructed, and after the new road girder is supported by the temporary bridge pier, the existing structure is disassembled and removed, and the new road A method of replacing a bridge in which an abutment or pier is erected along a girder, a main girder is installed between them, and a new road girder is supported by the main girder, and then the temporary pier is disassembled and removed. In this case, the temporary bridge pier is erected at the end of a newly installed bridge girder, the newly installed road girder is supported by a girder built on the temporary bridge pier, and the girder is used as a receiving beam. A method for replacing a bridge, wherein the bridge is left as a structural member of the bridge, and the new road girder is used as a construction girder of the new bridge and left as a structural member of the new bridge after the use.   After removing the existing structure, abutments or piers are erected outside the newly constructed girder and at both ends of the construction section, the main girder is installed between the abutments or piers, and the girder is installed on the main girder. The bridge replacement method according to claim 7, wherein both ends of the material are connected, and the new girder girder is supported by the main girder, and then the temporary pier of the construction section is disassembled and removed.   The bridge replacement method according to claim 7, wherein two girder members are installed on a single temporary pier, and an end portion of a new road girder adjacent to the girder material is supported.   8. The method of replacing a bridge according to claim 7, wherein after the existing structure is removed, the removed space is used as a girder manufacturing yard or a girder erection yard.

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