JP6905556B2 - Truss bridge member replacement method and replacement method - Google Patents

Description

The present invention relates to a truss bridge member replacement method and a replacement method for removing an old member from an existing truss bridge and replacing it with a new member.

Conventionally, as a truss bridge used for a road bridge, a railway bridge, a water pipe bridge, etc., a truss structure using a truss structure in which an upper chord member and a lower chord member are connected by a plurality of diagonal members is known. Warren trusses in which the directions of the timbers are alternated, double warren trusses in which diagonal members are crossed in an X shape, and the like are common. There is also a type in which a vertical lumber is added to reduce the load on each lumber.

By the way, in a truss bridge, after a long period of time has passed since it was completed, the truss members deteriorate due to corrosion of steel materials and the like, and it is necessary to replace the bridge body or replace the members.

As one of the methods for replacing the bridge body, there is a construction method in which the bridge body is supported from below by a temporary receiving facility such as a vent, and the truss members are partially removed and replaced with new members. As another method, there is a construction method in which the bridge body is suspended and held from above by a temporary suspension facility such as a cable, and the truss members are partially removed and replaced with new members. Furthermore, there is also a construction method in which the entire bridge body is removed all at once with a crane, and disassembled and replaced in the yard. Further, there is also known a construction method in which each member constituting the truss is removed individually and replaced individually (see, for example, Patent Document 1). In this construction method, the compressive force or tensile force acting on the member is reduced by tightening the gap between the grids of the member to be replaced with a tightening tool so that the pin can be easily removed.

Japanese Unexamined Patent Publication No. 2006-336371

However, as described above, in the construction method in which the truss member is removed while supporting the bridge body from below with temporary receiving equipment such as vents, the temporary receiving equipment such as vents is always installed under the girder during the construction period. There is a problem that the lower digits are occupied for a long period of time. In particular, on rivers, the construction period is limited to the dry season, and there is a risk that temporary receiving equipment and bridges will collapse due to unexpected flooding.

In addition, in the construction method of removing the truss members while suspending the bridge body from above with temporary suspension equipment such as cables, a steel tower and anchors for installing the cables are required, which makes the equipment large-scale and with the removal of the members. Since the suspension load of the cable changes, there is a problem that the shape management of the bridge body during construction becomes complicated.

Furthermore, in the construction method in which the entire bridge body is removed all at once with a crane, a large crane is used, so a vast site must be secured at the crane installation location, and ground improvement work according to the crane used is also required. Become. In this case, it is necessary to disperse the stress by using a suspension balance in order to prevent the truss from being distorted when the entire bridge body is suspended by a crane, and there is also a problem that the number of equipment used for removal increases.

In addition, in the construction method in which each member constituting the truss is removed individually and replaced individually, if the pin of the rating is removed, all the other members connected to the same pin will also be removed. There is a problem that it becomes impossible to maintain independence and construction cannot be performed on a truss bridge in which many members are pin-connected to one point. Moreover, since the tightening work is performed for each grid of each member, if there are many members to be replaced, the setup change work of the tightening tool is increased, and the work efficiency is significantly lowered. Further, in the case of a bridge (truss bridge), it is difficult to replace the compression member.

Further, when removing the member, if another member connected to the truss point is fixed by a reinforcing plate or the like, the member can be replaced while maintaining the truss shape. In this case, the member can be replaced. There is a problem that the grade points become rigid and excessive bending stress and shearing force are generated in the truss member.

The present invention has been made in view of the above problems, and an object of the present invention is a truss in which members can be replaced or replaced with a minimum of equipment while maintaining the independence of a bridge body which is a truss structure. The purpose is to provide a method for replacing members and a method for replacing bridge members.

The present invention is a method of replacing a member of a truss bridge in which an existing truss member is removed from a bridge body formed by connecting a plurality of truss members and replaced with a new truss member in order to achieve the above object. A truss member is attached, a temporary truss is formed on a part of the existing bridge body by the temporary truss member and a part of the existing truss members, and the temporary truss keeps the truss shape of a part of the bridge body other than the temporary truss. The existing truss member is removed from the portion, and a new truss member is attached to the portion from which the existing truss member has been removed.

Further, in order to achieve the above object, the present invention supports both ends in a truss bridge member replacement method in which an existing truss member is removed from a bridge body formed by connecting a plurality of truss members and replaced with a new truss member. attaching a temporary truss member to the bridge member in a state of being supported by a portion of the temporary truss members and the existing by truss members forming a temporary truss part of the bridge of the existing, a portion of the bridge member by temporary trusses truss shape except take existing truss member in a portion other than the still tentative truss holding the on bearing, and to attach a new truss member to the portion removed existing truss member.

As a result, the temporary truss is formed by the temporary truss member and some of the truss members, and other truss members are removed while the temporary truss holds the truss shape. Therefore, the bridge body, which is a truss structure, is self-supporting. Sex is preserved.

According to the present invention, since other truss members can be removed while maintaining the truss shape by the temporary truss, the members can be replaced or hung with the minimum equipment while maintaining the independence of the bridge body which is the truss structure. Can be replaced.

Partial side view of a truss bridge showing the first embodiment of the present invention Side view showing the member replacement process Side view showing the member replacement process Side view showing the member replacement process Side view showing the member replacement process Side view showing the member replacement process Side view showing the member replacement process Side view showing the member replacement process Side view showing the member replacement process Side view showing the member replacement process Side view showing a modification of the first embodiment Side view which shows the member replacement process which concerns on 2nd Embodiment of this invention. Side view showing the member replacement process Side view showing the member replacement process Side view showing the member replacement process Side view showing the member replacement process Side view showing the member replacement process Side view which shows the member replacement process which concerns on 3rd Embodiment of this invention. Side view showing the member replacement process Side view showing the member replacement process Side view showing the member replacement process Side view showing the member replacement process Side view showing the member replacement process Side view showing the member replacement process Side view showing the member replacement process Side view showing the member replacement process Side view showing the member replacement process Side view showing the member replacement process Side view showing the member replacement process

1 to 10 show the first embodiment of the present invention, and show a method of replacing a member of a truss bridge for removing an old member from an existing truss bridge and replacing it with a new member. ..

The truss bridge shown in the figure includes an upper chord member 1 as one chord member arranged above the bridge body, a lower chord member 2 as the other chord member arranged below the bridge body, and an upper chord member 1. It is composed of a plurality of vertical members 3 connecting the lower chord member 2 and a plurality of diagonal members 4 connecting the upper chord member 1 and the lower chord member 2, and these members form a truss member and pin connect the points to each other. Has been done. The truss bridge shown in FIG. 1 is the one before the members are replaced, and the floor slab, the horizontal girder, and the vertical girder are not shown.

The upper chord member 1 is made of a steel material extending from one end to the other end in the bridge axis direction, and is formed in an arch shape that warps upward.

The lower chord member 2 is made of a steel material extending from one end to the other end in the bridge axis direction, and is formed in a straight line in the horizontal direction.

Each vertical member 3 is made of a steel material extending in the vertical direction from the upper chord member 1 to the lower chord member 2, and is arranged at intervals in the bridge axis direction from each other. The vertical members 3 at both ends in the bridge axial direction are supported by the abutment 6 via the bearings 5, respectively.

Each diagonal member 4 is made of a steel material that extends diagonally from the upper chord member 1 to the lower chord member 2, and two diagonal members 4 intersect in an X shape between some vertical members 3 on the central side in the bridge axis direction. A diagonal member 4 is provided between the other vertical members 3 on both ends in the bridge axis direction. Further, each diagonal member 4 forms one diagonal member 4 by connecting two members divided into upper and lower parts by a connecting member 4a.

Next, the member replacement method of the present embodiment will be described with reference to FIGS. 2 to 10. In the figure, the existing members before replacement are shown in black, and the members after replacement and the members not to be replaced are shown in white. Further, in the member replacement method of the present embodiment, a temporary chord member 7 as a temporary truss member and a plurality of temporary diagonal members 8 are used.

The temporary chord member 7 is made of a linear steel material extending from one end to the other end in the bridge axis direction, and is detachably connected to each vertical member 3 by bolts.

Each temporary lumber 8 is made of a member whose length can be adjusted, such as a well-known turnbuckle, one end of which is detachably connected to the temporary chord member 7, and the other end of which is detachable to the upper chord member 1 or the lower chord member 2. It is designed to be connected to.

In the present embodiment, since the vertical lumber 3 of the truss members may not be deteriorated as compared with other members, only the upper chord member 1, the lower chord member 2 and each diagonal member 4 are replaced, and each vertical lumber 3 is replaced. Shows an example of using it as it is without replacing it.

First, as shown in FIG. 2, the floor slab, the horizontal girder, and the vertical girder are removed from the existing bridge body, and the temporary chord member 7 is attached between the upper chord member 1 and the lower chord member 2 as shown in FIG. In this case, the temporary chord member 7 is arranged on the lower end side (closer to the lower chord member 2) of each vertical member 3. Next, the upper chord member 1 and the temporary chord member 7 are connected by a plurality of temporary diagonal members 8. In this case, one end of each temporary lumber 8 is connected to the connecting point between the temporary lumber 7 and the vertical lumber 3, and the other end is connected to the connecting point between the upper chord lumber 1 and the slanted lumber 4. As a result, a temporary truss is formed by the upper chord member 1, the temporary chord member 7, each vertical member 3, and each temporary diagonal member 8.

Next, as shown in FIG. 4, the connecting member 4a of each lumber 4 is removed to remove the lower end side of each lumber 4, and the lower chord lumber 2 is removed from each vertical lumber 3. At that time, since the temporary truss is formed by the upper chord member 1, the temporary chord member 7, each vertical member 3 and each temporary diagonal member 8, the truss shape is formed even if the lower chord member 2 and the lower end side of each diagonal member 4 are removed. Retained.

Subsequently, as shown in FIG. 5, a new lower chord member 20 is attached to each vertical lumber 3, the lower end side of the new diagonal member 40 is connected to the new lower chord member 20, and the lower end side of the new diagonal member 40 is connected. After connecting to the upper end side of the existing diagonal member 4, the temporary string member 7 and each temporary diagonal member 8 are removed as shown in FIG.

Next, as shown in FIG. 7, a temporary chord member 7 is attached to the upper end side (closer to the upper chord member 1) of each vertical member 3, and a new lower chord member 20 and the temporary chord member 7 are attached by a plurality of temporary diagonal members 8. connect. In this case, one end of each temporary lumber 8 is connected to the connecting point between the temporary chord member 7 and the vertical lumber 3, and the other end is connected to the connecting point between the lower chord member 20 and the lower end side of the oblique lumber 40. As a result, a temporary truss is formed by the lower chord member 20, the temporary chord member 7, each vertical member 3, and each temporary diagonal member 8.

Subsequently, as shown in FIG. 8, the upper end side and the upper chord member 1 of each diagonal member 4 are removed. At that time, since the temporary truss is formed by the lower chord member 20, the temporary chord member 7, each vertical member 3 and each temporary diagonal member 8, the truss shape is formed even if the upper chord member 1 and the upper end side of each diagonal member 4 are removed. Retained.

Then, as shown in FIG. 9, a new upper chord member 10 is attached to each vertical lumber 3, the upper end side of the new diagonal lumber 40 is connected to the new upper chord member 10, and the upper end side of the new diagonal lumber 40 is slanted. It is connected to the lower end side of the lumber 40. After that, as shown in FIG. 10, the temporary chord member 7 and each temporary diagonal member 8 are removed to complete the member replacement step of the present embodiment.

As described above, according to the present embodiment, the temporary chord member 7 is attached between the upper chord member 1 and the lower chord member 2, and the temporary chord member 7 and the upper chord member 1 are connected by a plurality of temporary diagonal members 8. Since a temporary truss was formed, the lower end side of the lower chord member 2 and the diagonal member 4 connected to the lower chord member 2 was removed, and the lower end side of the new lower chord member 20 and the new diagonal member 40 was attached. The lower end side of the lower chord member 2 and the diagonal member 4 can be removed while holding the truss structure, and the members can be replaced with the minimum equipment while maintaining the independence of the bridge body which is a truss structure.

Further, after replacing the lower end side of the lower chord member 2 and the diagonal member 4 with the lower end side of the new lower chord member 20 and the new diagonal member 40, the temporary chord member 7 and the new lower chord member 20 are replaced with a plurality of temporary diagonal members 8. To form another temporary truss by connecting with, and replacing the upper end side of the upper chord member 1 and the diagonal member 4 connected to the upper chord member 10 with the upper end side of the new upper chord member 10 and the new diagonal member 40. Not only 2 but also the upper chord member 1 and each diagonal member 4 can be replaced with new members, and the replacement work can be easily performed in which the existing vertical members 3 are left as they are.

In this case, when the temporary truss is formed by the temporary chord member 7, the lower chord member 2, and each temporary diagonal member 8, the temporary chord member 7 is arranged closer to the lower chord member 2, and the temporary chord member 7, the new lower chord member 20, and each of them are arranged. Since the temporary chord member 7 is arranged closer to the upper chord member 1 when forming another temporary truss by the temporary diagonal member 8, each temporary truss can be increased in the vertical direction, and the strength of each temporary truss can be increased. Can be sufficiently secured.

Further, by applying an axial force to the temporary chord member 7 forming the temporary truss, the lower chord member 2 can be removed in a state where the axial tensile force or compressive force generated in the lower chord member 2 is reduced. , The pin of the rating point can be easily pulled out, and the lower chord member 2 can be easily removed. That is, as shown in FIG. 11, a plurality of axial force applying devices 7a made of jacks and the like are provided on the temporary chord member 7, and each axial force applying device 7a provides a direction opposite to the direction of stress between each rating point of the lower chord member 2. Applying tensile or compressive force. In this case, since the temporary chord member 7 is arranged closer to the lower chord member 2, the axial force of each axial force applying device 7a is reliably transmitted from the temporary chord member 7 to the lower chord member 2 via each vertical member 3. .. Further, the temporary chord member 7 is divided in the longitudinal direction by each axial force applying device 7a, and can be expanded and contracted in the longitudinal direction between the connection points with the vertical members 3. Although FIG. 11 shows a temporary chord member 7 to which an axial force is applied, an axial force may be applied to the temporary diagonal member 8.

12 to 17 show a second embodiment of the present invention, in which the lower chord member 2 is replaced and then the upper chord member 1 is replaced with the temporary chord member 7 attached at the same position. The same components as those in the first embodiment are designated by the same reference numerals. In addition, the existing members before replacement are shown in black, and the members after replacement and the members not to be replaced are shown in white.

First, as shown in FIG. 12, a temporary chord member 7 is attached between the upper chord member 1 and the lower chord member 2. In this case, the temporary chord member 7 is arranged at an intermediate position between the upper chord member 1 and the lower chord member 2. Next, the upper chord member 1 and the temporary chord member 7 are connected by a plurality of temporary diagonal members 8. In this case, one end of each temporary lumber 8 is connected to the connecting point between the temporary lumber 7 and the vertical lumber 3, and the other end is connected to the connecting point between the upper chord lumber 1 and the slanted lumber 4. As a result, a temporary truss is formed by the upper chord member 1, the temporary chord member 7, each vertical member 3, and each temporary diagonal member 8.

Next, as shown in FIG. 13, the connecting member 4a of each lumber 4 is removed to remove the lower end side of each lumber 4, and then the lower chord member 2 is removed from each vertical lumber 3. At that time, since the temporary truss is formed by the upper chord member 1, the temporary chord member 7, each vertical member 3 and each temporary diagonal member 8, the truss shape is formed even if the lower chord member 2 and the lower end side of each diagonal member 4 are removed. Retained.

Subsequently, as shown in FIG. 14, a new lower chord member 20 is attached to each vertical member 3, the lower end side of the new diagonal member 40 is connected to the new lower chord member 20, and the lower end side of the new diagonal member 40 is connected. After connecting to the upper end side of the existing diagonal member 4, each temporary diagonal member 8 is removed with the temporary string member 7 attached at the same position as shown in FIG.

Next, the new lower chord member 20 and the temporary chord member 7 are connected by a plurality of temporary diagonal members 8. In this case, one end of each temporary lumber 8 is connected to the connecting point between the temporary chord member 7 and the vertical lumber 3, and the other end is connected to the connecting point between the lower chord member 20 and the lower end side of the oblique lumber 40. As a result, a temporary truss is formed by the lower chord member 20, the temporary chord member 7, each vertical member 3, and each temporary diagonal member 8.

Subsequently, as shown in FIG. 16, the upper end side and the upper chord member 1 of each diagonal member 4 are removed. At that time, since the temporary truss is formed by the lower chord member 20, the temporary chord member 7, each vertical member 3 and each temporary diagonal member 8, the truss shape is formed even if the upper chord member 1 and the upper end side of each diagonal member 4 are removed. Retained.

Then, as shown in FIG. 17, a new upper chord member 10 is attached to each vertical lumber 3, the upper end side of the new diagonal lumber 40 is connected to the new upper chord member 10, and the upper end side of the new diagonal lumber 40 is slanted. It is connected to the lower end side of the lumber 40. After that, by removing the temporary chord member 7 and each temporary diagonal member 8, the member replacement step of the present embodiment is completed.

As described above, according to the present embodiment, when the temporary truss is formed by the temporary chord member 7, the upper chord member 1, and each temporary diagonal member 8, the temporary chord member 7 is arranged between the upper chord member 1 and the lower chord member 2. Since the temporary chord material 7 is arranged between the upper chord material 1 and the lower chord material 2 and another temporary truss is formed by the temporary chord material 7, the new lower chord material 2 and each temporary diagonal material 8, the lower chord material 7 is formed. After replacing 2, the upper chord material 1 can be replaced without removing the temporary chord material 7 once, so that the number of steps required for attaching and detaching the temporary chord material 7 can be reduced, and work efficiency can be improved. Can be done.

18 to 29 show a third embodiment of the present invention, in which the bridge body is replaced by replacing all the members of the upper chord member 1, the lower chord member 2, each vertical member 3 and each diagonal member 4. It was made like this. The same components as those in the first embodiment are designated by the same reference numerals. In addition, the existing members before replacement are shown in black, and the members after replacement and the members not to be replaced are shown in white.

First, as shown in FIG. 18, the deck, the horizontal girder, and the vertical girder are removed from the existing bridge body, and the temporary chord member 7 is attached between the upper chord member 1 and the lower chord member 2 as shown in FIG. In this case, the temporary chord member 7 is arranged slightly closer to the lower chord member 2 from the intermediate position between the upper chord member 1 and the lower chord member 2. Next, the upper chord member 1 and the temporary chord member 7 are connected by a plurality of temporary diagonal members 8. In this case, one end of each temporary lumber 8 is connected to the connecting point between the temporary lumber 7 and the vertical lumber 3, and the other end is connected to the connecting point between the upper chord lumber 1 and the slanted lumber 4. As a result, a temporary truss is formed by the upper chord member 1, the temporary chord member 7, each vertical member 3, and each temporary diagonal member 8.

Next, as shown in FIG. 20, the connecting member 4a of each diagonal member 4 is removed to remove the lower end side of each diagonal member 4, and the lower ends of the vertical members 3 other than the vertical members 3 located at both ends of the bridge body. The side is cut and removed, and the lower chord member 2 is removed from the vertical timbers 3 at both ends. At that time, since the temporary truss is formed by the upper chord member 1, the temporary chord member 7, each vertical member 3, and each temporary diagonal member 8, the lower chord member 2, the lower end side of the vertical member 3 other than both ends, and each diagonal member 4 The truss shape is maintained even if the lower end side of is removed.

Subsequently, as shown in FIG. 21, the lower end side of the new vertical lumber 30 is connected to the upper end side of the vertical lumber 3 other than both ends, and the new lower chord member 20 is attached to each of the vertical lumbers 3 and 30. Further, after connecting the lower end side of the new diagonal member 40 to the new lower chord member 20 and connecting the lower end side of the new diagonal member 40 to the upper end side of the existing diagonal member 4, tentatively as shown in FIG. Remove the chord member 7 and each temporary lumber member 8.

Next, as shown in FIG. 23, the temporary chord member 7 is attached to the upper end side of each vertical lumber 3 and the new vertical lumber 30, and the new lower chord member 20 and the temporary chord member 7 are attached to the plurality of temporary lumber members 8. connect. In this case, one end of each temporary lumber 8 is connected to the connecting point between the temporary chord member 7 and the vertical lumber 3, and the other end is connected to the connecting point between the lower chord member 20 and the lower end side of the oblique lumber 40. As a result, the temporary truss is formed by the lower chord member 20, the temporary chord member 7, the vertical members 3 and 30, and the temporary diagonal members 8.

Subsequently, as shown in FIG. 24, the upper end side of the vertical lumber 3 other than both ends, the upper end side of each diagonal lumber 4, and the upper chord member 1 are removed. At that time, since the temporary truss is formed by the lower chord member 20, the temporary chord member 7, each vertical member 3 and each temporary diagonal member 8, the truss shape is formed even if the upper chord member 1 and the upper end side of each diagonal member 4 are removed. Retained.

Next, as shown in FIG. 25, the upper end side of the new vertical lumber 30 is connected to the lower end side of the vertical lumber 3 other than both ends, and the new upper chord member 10 is attached to each of the vertical lumbers 3 and 30. Further, the upper end side of the new diagonal member 40 is connected to the new upper chord member 10, and the upper end side of the new diagonal member 40 is connected to the lower end side of the diagonal member 40. After that, as shown in FIG. 26, the temporary chord member 7 and each temporary diagonal member 8 are removed.

After that, as shown in FIG. 27, the entire bridge body is lifted by a jack, a crane, or the like, and as shown in FIG. 28, the vertical members 3 at both ends are replaced with new vertical members 30, and each bearing 5 is replaced with a new bearing 50. After the replacement, as shown in FIG. 29, the entire bridge body is lowered to the bearing 50 to complete the member replacement step of the present embodiment.

As described above, according to the present embodiment, the lower end side of the vertical member 3 other than both ends is removed together with the lower chord member 2 and replaced with a new lower end side of the vertical member 30, and the upper end side of the vertical member 3 other than both ends is the upper chord. It was removed together with the material 1 and replaced with the new vertical material 30 on the upper end side, and the entire bridge body was lifted so that the vertical materials 3 at both ends were replaced with the new vertical material 30. All the members of the member 3 and each diagonal member 4 can be replaced, and the bridge body can be completely renewed.

In each of the above-described embodiments, the connecting member 4a of each diagonal member 4 is removed to remove the lower end side from the upper end side of the diagonal member 4, but the diagonal member is not connected by the connecting member. When the member is made of a book, the lower end side of the diagonal member may be cut and removed as in the case of the vertical member 3 other than both ends of the third embodiment.

The present invention can also be applied to the case where only the upper chord member 1 or only the lower chord member 2 is replaced with a new member.

1 ... Upper chord lumber, 2 ... Lower chord lumber, 3 ... Vertical lumber 3, 4 ... Diagonal lumber, 5 ... Bearing, 6 ... Abutment, 7 ... Temporary chord lumber, 7a ... Axial force applying device, 8 ... Temporary lumber, 10 ... Upper chord material, 20 ... lower chord material, 30 ... vertical material 3, 40 ... diagonal material, 50 ... bearing.

Claims (3)

In a truss bridge member replacement method in which an existing truss member is removed from a bridge body formed by connecting a plurality of truss members and replaced with a new truss member.
Attach a temporary truss member to the bridge body,
A temporary truss is formed on a part of the existing bridge body by the temporary truss member and a part of the existing truss member.
The temporary truss removes the existing truss members in the parts other than the temporary truss while maintaining the truss shape of a part of the bridge body .
A method for replacing truss bridge members, which comprises attaching a new truss member to a portion from which an existing truss member has been removed. In a truss bridge member replacement method in which an existing truss member is removed from a bridge body formed by connecting a plurality of truss members and replaced with a new truss member.
Attach temporary truss members to the bridge body with both ends supported by bearings,
A temporary truss is formed on a part of the existing bridge body by the temporary truss member and a part of the existing truss member.
Temporary truss part of the truss shape of the bridge member Except take existing truss member in a portion other than the still tentative truss holding the on bearing by,
A method for replacing truss bridge members, which comprises attaching a new truss member to a portion from which an existing truss member has been removed. A method for replacing a truss bridge, which comprises replacing all existing truss members with new truss members by using the method for replacing truss bridge members according to claim 1 or 2.

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