JP2021050512A - Bridge replacement method and bridge upper structure - Google Patents

Abstract

To provide a bridge replacement method that can be applied even when the construction conditions under the bridge are severe.SOLUTION: The replacement of an existing bridge 10 with a new bridge 20 is performed as follows. Rail-shaped first connection means 31 extending in a direction of the bridge axis is provided on a lower surface side of a new bridge upper structure 21. The new bridge upper structure 21 is carried in using an upper surface of the existing bridge upper structure as a carrying path, and the new bridge superstructure 21 is temporarily installed on an upper part of the existing bridge upper structure to temporarily support both ends via a temporary vent. The first connection means 31 is connected to second connection means 32 being a hanging rod, an existing bridge upper structure removal equivalent part 11A is suspended and supported by the new bridge upper structure 21 via the second connection means 32, the existing bridge upper structure is cut to form a removal block 11A, and the removal block 11A is lifted and slid through the first connection means 31 to be removed. The removal block 11A is repeatedly formed to remove the existing bridge upper structure, and existing bridge piers are removed in the same manner. The new bridge upper structure 21 is then lowered and installed.SELECTED DRAWING: Figure 1

Description

The present invention relates to a replacement method in which an existing bridge is removed and a new bridge is erected.

Generally, the life of concrete is said to be 60 to 100 years. After more than half a century has passed for civil engineering structures mainly made of concrete and iron, it is often considered whether to make large-scale repairs to extend the service life or to remove existing structures and construct new ones.

As for bridges, the replacement of existing bridges with new ones is being considered. However, construction conditions are often strict due to restrictions due to the environment around the bridge. In addition, the replacement work includes a removal process and a new construction process, so it is easy to take a long time. Therefore, various replacement methods have been proposed according to the construction conditions (for example, Patent Document 1).

For example, in the replacement method disclosed in Patent Document 1, first, the existing bridge girder erected on the pier is supported from below by a jack installed on the transport carriage. Cut both ends of the existing bridge girder with a length shorter than the pier span. Operate the jack to lower the existing bridge girder. With the existing bridge girder supported from below by the jack, the existing bridge girder is carried out by the transport trolley.

On the other hand, a new bridge girder will be constructed on the remaining existing bridge girder adjacent to the new bridge girder replacement position. In addition, a new bridge girder will be lifted by a large crane and erected between the piers.

Japanese Unexamined Patent Publication No. 2003-034911

FIG. 12 is an example of an existing bridge. In urban areas, multiple railroads run side by side in narrow valleys, and bridges may be erected so as to cross the valley and cross over the railroad tracks. Bridges built over half a century ago generally have short spans and are supported by piers in addition to the piers at both ends. Multiple railroads pass between piers or between piers.

When inspecting or maintaining bridges as described above, it is necessary to always consider the railway operation status. In particular, the work conditions for inspection and maintenance of piers sandwiched between railroad tracks are extremely strict. Therefore, it may be determined that replacement is preferable. In recent years, the span has tended to become longer, and support by piers is no longer necessary. If the bridge structure is simplified, inspection and maintenance will be easier.

In the replacement method described in Patent Document 1, the transport trolley is kept on standby under the bridge. Under the construction conditions shown in FIG. 12, it is not preferable to keep the transport trolley on standby under the bridge, and it is difficult to apply the replacement method described in Patent Document 1. It is necessary to consider a replacement method suitable for the above construction conditions.

The present invention solves the above problems, and an object of the present invention is to provide a bridge replacement method that can be applied even when the construction conditions under the bridge are severe.

The present invention that solves the above problems is a bridge replacement method. A first connecting means extending in the direction of the bridge axis is provided on the lower surface side of the new bridge upper structure, and the new bridge upper structure is carried in using the upper surface of the existing bridge upper structure as a carrying path to carry in the existing bridge. The new bridge upper structure is temporarily installed on the upper part of the upper structure, both ends of the new bridge upper structure are temporarily supported, the first connecting means and the second connecting means are connected, and the second connecting means is used. Then, the part corresponding to the removal of the existing bridge upper structure is suspended and supported by the new bridge upper structure, the part corresponding to the removal of the existing bridge upper structure is cut, and the part corresponding to the removal of the existing bridge upper structure is lifted. The existing bridge upper structure is removed by sliding through the first connecting means, the removal of the plurality of existing bridge upper structures is repeated, the existing bridge upper structure is removed, and the new bridge upper structure is lowered. Set up.

In the above procedure, there is no work under the bridge, and most of the work can be performed using the upper surface of the existing bridge superstructure. This makes it applicable even when the construction conditions under the bridge are strict.

In addition, the temporary support state of the new bridge superstructure can be used as temporary equipment for removing the existing bridge superstructure.

In the present application, the superstructure includes a girder and a floor slab.

In the above invention, preferably, in the removal of the part corresponding to the removal of the existing bridge superstructure, the bridge is hung on the remaining part of the existing bridge superstructure, and the upper surface of the remaining part of the existing bridge superstructure is used as a carrying path.

In this way, the rest of the existing bridge superstructure can be effectively utilized. That is, the work under the bridge can be eliminated.

In the above invention, preferably, in the removal of the part corresponding to the removal of the existing bridge superstructure, the existing bridge is carried out of the existing bridge in a sliding state.

As a result, the remaining part of the existing bridge superstructure can be effectively used as a work area.

In the above invention, preferably, the removal corresponding portion of the existing bridge lower structure is suspended and supported by the new bridge upper structure via the second connecting means, the removal corresponding part of the existing bridge lower structure is cut, and the existing bridge lower structure is cut. The part corresponding to the removal of the bridge lower structure is lifted, further slid and removed via the first connecting means, and the removal of the plurality of existing bridge lower structures is repeated to remove the existing bridge lower structure. To do.

The construction method of the present application can also be applied to the removal of the existing bridge substructure. In the present application, the substructure includes a pier and an abutment.

In the above invention, preferably, two or more of the second connecting means are provided in the direction orthogonal to the bridge axis, and the second connecting means are connected to each other via a hanging girder.

As a result, the hanging position can be adjusted and the hanging state is stabilized.

In the above invention, preferably, the state in which the first connecting means is provided is maintained even after the main construction of the new bridge superstructure.

As a result, it can be reused even during inspections after the main installation.

In the above invention, preferably, the existing bridge superstructure is provided on a railroad track or a road extending in the bridge axis crossing direction.

The construction method of the present application is suitable when the construction conditions under such a bridge are severe. There is no work under the bridge, and it is not easily affected by the situation under the bridge.

The present invention that solves the above problems is a bridge superstructure. On the lower surface side of the new bridge superstructure, a rail-shaped first connecting means extending in the direction of the bridge axis is provided.

That is, the first connecting means is a part of the new bridge and can be reused even after the main construction.

The present invention that solves the above problems is a bridge superstructure. A rail-shaped first connecting means extending in the direction of the bridge axis is provided on the lower surface side, and the second connecting means is connected to the first connecting means and slid along the first connecting means. It is movable.

The connection mechanism including the first connection means and the second connection means can be used in the removal process of the replacement work. In addition, the first connection means can be reused even after the main installation.

According to the replacement method according to the present invention, it can be applied even when the construction conditions under the bridge are severe.

Cross-sectional view of the system of the present application Connection mechanism (examples and modifications) Connection mechanism (variation example) Perspective view of an example of removing the existing superstructure (first half) Perspective view of an example of removing the existing superstructure (second half) Perspective view of an example of removing the existing substructure New superstructure erection example perspective view New bridge example perspective view Example of removing the existing superstructure Perspective view (deformed example) Example of removing the existing superstructure Perspective view (deformed example) Example of removing the existing superstructure Perspective view (deformed example) Perspective view of an example of an existing bridge

~ Example of existing bridge ~
FIG. 12 is an example of an existing bridge 10 to which the present invention is applied. In urban areas, a plurality of railways run side by side in a narrow valley, and a bridge 10 is erected so as to straddle the valley and cross over a railroad track. Existing bridges generally have short spans, and the superstructure (a broad concept including bridge girders and slabs) 11 is supported by the substructures of the abutments 12 and 12 and the piers 13 and 13 at both ends. The illustration of other configurations such as bearings is omitted. A plurality of railroads pass between piers 13 and 13 or between piers 12 and 13.

The replacement work is complicated because the removal process and the new construction process are complicated. In addition, it is necessary to always consider the railway operation status in the replacement work. For example, even if the replacement work is carried out at night when there is no train operation, it takes time to carry in and out the equipment and materials, and it is necessary to remove temporary equipment every time, so it is practically difficult to work under the bridge. ..

Under the above construction conditions, it is preferable that there is no work under the bridge as much as possible.

~ Characteristic composition ~
The replacement method according to the present embodiment is performed by a system having a characteristic configuration.

FIG. 1 is a cross-sectional view of this system. This system has a connection mechanism 30 for connecting the existing bridge 10 (see FIG. 12) and the new bridge 20 (see FIG. 8). The connection mechanism 30 is formed by connecting the first connection means 31 and the second connection means 32.

The first connecting means 31 has a structure extending in a rail shape in the direction of the bridge axis. Two first connecting means 31, 31 are extended in the bridge axis direction on the lower surface side of the new bridge superstructure 21 (see FIG. 4 described later).

The second connecting means 32 is a hanging rod. One end of the suspension rod 32 is connected to the existing removal target and can be suspended and supported, and the other end is slidably connected to the first connecting means 31 on the first connecting means 31. The suspension rod 32 can suspend the existing removal target by adjusting the length.

In the example of FIG. 1, the suspension rod 32 includes an upper suspension rod 33 and a lower suspension rod 34.

The upper end of the suspension rod 33 is slidably connected to the first connecting means 31. The lower end of the hanging rod 33 is connected to the hanging girder 35. The connection mechanism between the first connecting means 31 and the suspension rod 33 is, for example, a fitting structure using a JES joint.

FIG. 2A is a JES joint which is an example of the connection mechanism. The JES joint has a hump-shaped end at one end having a C-shaped cross section, and the joints are fitted to each other by inserting the hump-shaped into each other's C-shaped space. FIG. 2B is a modified example of the connection mechanism. The cylindrical engaging portion at the upper end of the suspension rod 33 slides in the first connecting means 31 having a horseshoe-shaped space in cross section. The suspension rod 33 may have a width in the direction of the bridge axis.

FIG. 3 is another modification of the connection mechanism. The groove 31 extends in the bridge axial direction on the lower surface side of the new bridge superstructure 21. In other words, the first connecting means 31 having a groove is embedded so as to extend in the bridge axis direction on the lower surface side of the new bridge superstructure 21.

The upper end of the hanging rod 34 is engaged with the hanging girder 35 via the jack 36. The lower end of the suspension rod 34 is engaged with the existing removal target via a fastener 37 provided on the lower surface of the existing removal target (for example, the removal corresponding portion 11A of the existing bridge superstructure).

It should be noted that the work under the bridge can be reduced as much as possible by using the post-construction anchor instead of the engagement by the fastener 37.

The suspension girders 35 are arranged so that the direction orthogonal to the bridge axis is the longitudinal direction, and connection mechanisms 30 are provided at two positions at both ends of the suspension girders 35. That is, the hanging rods 32 and 32 are connected via the hanging girder 35. The hanging position of the existing removal target can be adjusted via the hanging girder 35.

The jack 36 is, for example, a center hole jack. By tensioning the hanging rod 34 with the jack 36, the existing removal target can be lifted.

The interaction between each configuration will be described in the replacement work procedure.

~ Replacement work procedure ~
4 and 5 are perspective views of an example of removing the existing superstructure. The replacement work includes a removal process and a new construction process. In particular, the procedure of the present application is characterized in that the removal process and the new installation process are interlocked with each other.

A new bridge superstructure 21 is constructed in advance outside the existing bridge superstructure 11. The erection girders may be extended at both ends so that the girder length can be adjusted. The new bridge superstructure 21 is carried in using the upper surface of the existing bridge superstructure 11 as a carrying path.

Alternatively, the components of the new bridge superstructure 21 may be carried in from the outside of the existing bridge superstructure 11 to construct the new bridge superstructure 21 on the upper surface of the existing bridge superstructure 11. The carry-in with the new bridge superstructure 21 includes the carry-in of component parts.

Temporary vents 41 and 41 are provided at both ends of the existing bridge superstructure 11 and on the grounds (semi-transparent and shown) on both sides of the existing bridge stand 12 in the direction perpendicular to the bridge axis. By widening the intervals between the temporary vents 41 and 41, it becomes easy to access the upper surface of the existing bridge superstructure 11.

While temporarily supporting both ends of the new bridge superstructure 21 by the temporary vents 41 and 41, jack up is performed, and the new bridge superstructure 21 is temporarily installed above the existing bridge superstructure 11. The width of the new bridge superstructure 21 is wider than the width of the remaining 11 width of the existing bridge superstructure.

Next, the existing bridge superstructure removal equivalent portion 11A connects the existing bridge superstructure removal equivalent portion 11A and the new bridge superstructure 21 via the connection mechanism 30 (see FIG. 1). As a result, the existing bridge superstructure removal equivalent portion 11A is suspended and supported by the new bridge superstructure 21. From the viewpoint of stability, the suspension support of a long object is generally 4 points or more (see FIG. 4).

In the suspended support state, the existing bridge superstructure removal equivalent portion 11A is cut to form a removal block. The removal block 11A is lifted via the jack 36 so that the lower surface of the removal block 11A is higher than the upper surface position of the existing bridge superstructure remaining portion 11B (see FIG. 4). As a result, the removal block 11A becomes slidable.

The carry-out carriage 42 is kept on standby in the existing bridge superstructure remaining portion 11B adjacent to the existing bridge superstructure removal equivalent portion 11A. The removal block 11A is slid via the first connecting means 31, and the removal block 11A is suspended from the carry-out carriage 42 via the jack 36 (see FIG. 5).

The upper surface of the remaining portion 11B of the existing bridge superstructure is used as a carry-out path for the carry-out carriage 42, and the removal block 11A is carried out. At this time, if the intervals between the temporary vents 41 and 41 are sufficiently wide, the temporary vents 41 and 41 can be carried out from between the temporary vents 41 and 41.

FIG. 6 is a perspective view of an example of removing the existing substructure. If a part of the existing bridge superstructure removal equivalent portion 11A is carried out and an opening is made, the existing bridge pier removal equivalent portion 13A can be accessed from above.

As a result of connecting the existing bridge pier removal equivalent portion 13A and the new bridge superstructure 21 via the connection mechanism 30, the existing bridge pier removal equivalent portion 13A is suspended and supported by the new bridge superstructure 21. As shown in the figure, two-point support may be used.

In the suspended support state, the existing bridge pier removal equivalent portion 13A is cut to form a removal block. In the procedure of carrying out the removal block 11A, the removal block 13A is slid and carried out via the first connecting means 31.

The procedure of carrying out the removal block 11A and the removal block 13A is repeated to remove the existing bridge superstructure remaining portion 11B and the existing pier remaining portion 13B.

FIG. 7 is a perspective view of an example of erection of a new superstructure. In a state where the existing bridge superstructure 11 and the existing pier 13 are all removed, the connection between the first connecting means 31 and the second connecting means 32 is released, and the second connecting means 32 is removed. Then, the temporary vents 41 and 41 jack down while temporarily supporting both ends of the new bridge superstructure 21. Remove the erection girders at both ends so as to adjust the girder length. The new bridge superstructure 21 is lowered and permanently installed at predetermined positions of the existing piers 12 and 12.

~effect~
The above procedure can be outlined as follows: suspension support for removal target → cutting → lifting → sliding → suspension to the upper surface of the existing bridge superstructure → carry-out. In the above procedure, as a general rule, there is no work under the bridge, and most of the work can be performed using the upper surface of the existing bridge superstructure 11.

That is, the replacement work can be carried out without being affected by the railway operation status. However, from the viewpoint of safety priority in construction practice, it seems that it is actually carried out at night when there is no train operation. However, even if it is limited to nighttime construction, preparatory work can be done on the upper surface of the existing bridge superstructure even during train operation, and there is no loading and unloading of materials and equipment to the railroad track or temporary construction, so the construction period is significantly shortened and safety It can be expected to secure the sex, and as a result, the cost will be reduced.

In addition, the removal process and the new construction process are interlocked with each other, in other words, the temporary support state of the new bridge superstructure 21 can be used as temporary equipment for removing the existing bridge superstructure 11 and removing the existing pier 13. Expected to shorten the construction period and reduce costs.

As described above, the replacement method according to the present embodiment can be applied even when the construction conditions under the bridge are severe such that a plurality of railways run in parallel in the bridge crossing direction.

-Use of the first connection means after the main installation-
FIG. 8 is an example of a new bridge 20 that has been replaced according to the present invention. Although the second connecting means 32 of the connecting mechanism 30 is removed, the first connecting means 31 remains installed on the lower surface side of the new bridge superstructure 21 even after the main installation. That is, the first connecting means 31 is a part of the new bridge 20.

When inspecting or maintaining the lower surface side of the new bridge superstructure 21, the work gondola (not shown) is suspended and slid by using the first connecting means 31. As a result, temporary work for inspection and maintenance is greatly reduced, and inspection and maintenance are facilitated.

~ Modification example ~
In order to facilitate the understanding of the present invention, the above embodiment has been described as an example, but the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the technical idea of the present invention.

FIG. 9 is a perspective view of a modified example of removing the existing superstructure. In the above embodiment, the removal block 11A is lifted (see FIG. 4), slid, hung on the carry-out carriage 42 (see FIG. 5), and the upper surface of the existing bridge superstructure remaining portion 11B is carried out as a carry-out path for the carry-out carriage 42. On the other hand, in the modified example, after the removal block 11A is lifted (see FIG. 4), it is slid to the end of the first connecting means 31, hung down, and carried out from the end of the existing bridge 10.

That is, in the modified example, the upper surface of the existing bridge superstructure remaining portion 11B is not used as a carrying path. As a result, the upper surface of the existing bridge superstructure remaining portion 11B can be effectively used as a work space, and workability and safety are further improved.

FIG. 10 is a perspective view of another modified example of removing the existing superstructure. In the above embodiment, the existing bridge superstructure 11 and the existing pier 13 are removed and the existing pier 12 is reused, whereas in the modified example, the existing bridge 12 is also removed and a new pier 22 is provided.

First, new piers 22 and 22 are provided on the outside of the existing piers 12 and 12 in the bridge axis direction. Temporary vents 41 and 41 are provided on the new piers 22 and 22, and both ends of the new bridge superstructure 21 are temporarily supported.

In the procedure of carrying out the removal block 11A and the removal block 13A, the existing abutment 12 is cut to form a removal block, and the removal block is slid and carried out via the first connecting means 31. At this time, if the removal block is slid to the new pier 22 and carried out from the new pier 22, the entire surface of the existing bridge superstructure remaining portion 11B can be effectively used as a work space.

In a state where the existing bridge superstructure 11 and the existing bridge superstructures 12 and 13 are all removed, the new bridge superstructure 21 is lowered and the new bridge superstructures 22 and 22 are permanently installed at predetermined positions.

If the width of the new bridge 22 is wider than the width of the existing bridge 12 and the width of the new bridge superstructure 21 is wider than the width of the existing bridge superstructure remaining 11B, a wide carry-out space can be secured and the workability is further improved.

FIG. 11 is a perspective view of another modified example of removing the existing superstructure. After the removal block 11A is lifted, it is slid, suspended on the adjacent existing bridge superstructure remaining portion 11B, divided into small pieces on the existing bridge superstructure remaining portion 11B, and carried out.

In the example of the existing bridge shown in FIG. 12, the existence of the existing pier 13 is premised, but the present invention can be applied to the existing bridge without the pier. In that case, of course, the step of removing the existing pier 13 is unnecessary. That is, in the present invention, the removal of the existing pier 13 is not essential.

By the way, existing bridges built more than half a century ago generally have a short span length, but we have examined the cross-sectional structure and materials, made PC bridges, arch bridges, cable-stayed bridges, suspension bridges, etc. By using it, the span length of the new bridge can be lengthened. As a result, no new piers are needed.

In the above embodiment, as an example in which the construction conditions under the bridge are strict, a case where a plurality of railways run in parallel in the direction of the bridge intersection (see FIG. 12) is mentioned, but a case where the main highways intersect under the bridge or It is also suitable when rivers intersect and the flow is fast and it is difficult to anchor the pontoon.

In the example of the existing bridge shown in FIG. 12, the road bridge is used, but a railway bridge may be used.

10 Existing bridge 11 Existing bridge superstructure 12 Existing bridge (substructure)
13 Existing pier (substructure)
20 New bridge 11 New bridge superstructure 12 Existing bridge (substructure)
30 Connection mechanism 31 First connection means (rail shape)
32 Second connection means (hanging rod)
33 Upper hanging rod 33 Lower hanging rod 35 Hanging girder 36 Jack 37 Fastener 41 Temporary vent 42 Carrying trolley

Claims (9)

On the lower surface side of the new bridge superstructure, a first connecting means extending in the direction of the bridge axis is provided.
The new bridge superstructure is carried in using the upper surface of the existing bridge superstructure as a carrying path.
The new bridge superstructure is temporarily installed on the upper part of the existing bridge superstructure, and both ends of the new bridge superstructure are temporarily supported.
The first connecting means and the second connecting means are connected, and the removal corresponding portion of the existing bridge superstructure is suspended and supported by the new bridge superstructure via the second connecting means.
The part corresponding to the removal of the existing bridge superstructure was cut.
The part corresponding to the removal of the existing bridge superstructure is lifted and further slid through the first connecting means to be removed.
Repeatedly removing the parts corresponding to the removal of the plurality of existing bridge superstructures, and removing the existing bridge superstructure.
A bridge replacement method characterized in that the superstructure of the newly constructed bridge is lowered and permanently installed. In the removal of the part corresponding to the removal of the existing bridge superstructure
Suspended on the rest of the existing bridge superstructure
The bridge replacement method according to claim 1, wherein the upper surface of the remaining portion of the existing bridge superstructure is used as a carrying path. In the removal of the part corresponding to the removal of the existing bridge superstructure
The bridge replacement method according to claim 1, wherein the bridge is carried out of the existing bridge in a sliding state. A portion corresponding to the removal of the existing bridge lower structure is suspended and supported by the new bridge upper structure via the second connecting means.
The part corresponding to the removal of the existing bridge substructure was cut.
The part corresponding to the removal of the existing bridge lower structure is lifted, and then slid and removed via the first connecting means.
The bridge replacement method according to any one of claims 1 to 3, wherein the removal of a plurality of existing bridge substructures corresponding to the removal is repeated, and the existing bridge substructure is removed. Two or more of the second connecting means are provided in the direction orthogonal to the bridge axis.
The bridge replacement method according to any one of claims 1 to 4, wherein the second connecting means are connected to each other via a suspension girder. The bridge replacement method according to any one of claims 1 to 5, wherein the state in which the first connecting means is provided is maintained even after the construction of the new bridge superstructure. The bridge replacement method according to any one of claims 1 to 6, wherein the existing bridge superstructure is provided on a railroad track or a road extending in the crossing direction of the bridge axis. A bridge superstructure constructed by the replacement method according to any one of claims 1 to 7.
A bridge superstructure characterized in that a first connecting means extending in the bridge axis direction is provided on the lower surface side of the bridge superstructure. A first connecting means extending in the direction of the bridge axis is provided on the lower surface side.
The second connecting means can slide along the first connecting means in a state of being connected to the first connecting means.
The bridge superstructure is characterized by this.

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