JP7061002B2 - How to repair a bridge - Google Patents

Description

The present invention is a method for repairing a bridge, and particularly relates to a method for repairing a bridge when there is no room for construction work in the vicinity.

It is said that there are hundreds of thousands of small-scale bridges installed in mountainous areas in Japan that need to be replaced or repaired from the time of construction.
As a technique for reinforcing and repairing such a bridge, a seismic retrofitting method such as attaching a reinforcing fiber sheet is known. (Patent Document 1)
Alternatively, a method of repairing or reinforcing a part of the structure of the bridge, such as a balustrade of the bridge, surface pavement, a floor slab, and a bearing, is known. (Patent Document 2)
In addition, a method is adopted in which all the old bridges are once dismantled and new bridges are rebuilt.
Alternatively, a construction method is also known in which an arch-shaped support frame that is convex upward is installed at the bottom of the existing bridge, and the space under the support frame and the existing bridge is filled with a consolidated material to support the load of the bridge. ing. (Patent Document 4)

Japanese Unexamined Patent Publication No. 10-110536 Japanese Unexamined Patent Publication No. 9-228321 Japanese Unexamined Patent Publication No. 2011-63993 Japanese Unexamined Patent Publication No. 2013-23789

The conventional method described above has the following problems.
<1> As mentioned in Patent Documents 1 to 3, what is generally adopted is the repair and reinforcement of a part of the bridge, and the one that covers the entire bridge cannot be found.
<2> The repair and reinforcement methods that are actually used at the site are methods that stop or partially restrict the passage on the bridge, which has a great impact on the surrounding environment and economic activities.
<3> In particular, the method of dismantling an old bridge and re-building a new one will make it impossible for the user to pass for a long period of time, or will temporarily construct a temporary pier, which is a big problem for users and orderers. It's a burden.
<4> The invention by the inventor, which solves this problem, is disclosed as Patent Document 3. However, the bridge was originally erected on the flow of flowing water from the mountain side, and the invention described in Patent Document 3 was insufficient to take measures against the flow under the bridge.
<5> Apart from that problem, the consolidation material is more expensive than ordinary earth and sand. Therefore, in the method shown in Patent Document 3, if the amount of the consolidation material used is reduced, it is easier to adopt. It is believed that there is.
<6> The construction method of Patent Document 4 does not reinforce a part of the bridge, but regenerates the entire bridge, so that there is an advantage that the construction can be performed without affecting the traffic on the road during the construction. However, there are generally few flat places near the bridge. Therefore, it was found that the work of integrally manufacturing an arch-shaped support frame near the bridge and pulling it under the bridge is difficult to construct in a steep or narrow site. ..

In order to solve the above problems, the bridge repair method of the present invention is:
In an existing bridge with abutments and abutments, or abutments and piers, or a floorboard between piers and piers.
After opening the flow path space inside between the abutments and the abutments and installing a split support frame divided in the direction parallel to the central axis of the bridge,
Multiple split support frames are formed as an integrated support frame group,
A barrier is formed on the outside of the bridge parallel to the central axis of the bridge.
It is a method of filling the inside of the space surrounded by this barrier wall and the upper surface of the support frame group with a solidifying material.
The outer end of the support frame group and the barrier wall are located away from the outside of the bridge in a plan view.
With the barrier wall resting on or in contact with the end of the support frame group,
And with the barrier wall securing the flow path space under the support frame group ,
And the height of the upper end of the barrier is set higher than the upper surface of the bridge.
It is characterized by filling the inside of the space surrounded by this barrier and the upper surface of the support frame group not only to the lower part of the bridge but also to the side and upper part and wrapping the bridge with the solidifying material. Is to be.

Since the bridge repair method of the present invention has been described above, some of the following effects can be obtained.
<1> The entire bridge can be regenerated instead of repairing or reinforcing a part of the bridge.
<2> The entire dilapidated bridge can be regenerated without being dismantled while maintaining its original state.
<3> Although it is a method of repairing the entire bridge, it does not affect the current traffic during the rehabilitation work, so it does not disturb the surrounding economic environment.
<4> Significant cost reduction can be expected while obtaining the same effect as dismantling an old bridge and constructing a new bridge again.
<5> Even when the width of the bridge is increased, it can be done with almost no effect on the traffic on the current bridge.
<6> Since it is not necessary to fill the flow path space formed in the space below the support frame with the solidifying material, the amount of the solidifying material used, which is expensive as compared with general earth and sand, can be significantly reduced. Can be done.
<7> Generally, in the case of bridges in mountainous areas, there are many cases where there is no flat land with a good foothold around them. However, in the method of the present invention, since the support frame is divided into a plurality of pieces in a direction parallel to the central axis of the bridge and sequentially pulled under the bridge, it can be adopted even in a field where a wide work site cannot be obtained.

Explanatory drawing of the state where the split support frame is installed at the bottom of the bridge. An explanatory diagram of a state in which a split support frame is installed at the bottom of the bridge to form a support frame group. Explanatory drawing of the state where the barrier is installed on the outside of the bridge. Explanatory drawing of the state where the barrier is constructed at a position away from the bridge. Explanatory drawing of an example of wrapping a bridge with a consolidation material.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

<1> Target bridge The existing bridge A, which is the target of the regeneration method of the present invention and the widening method as one of the regeneration methods, is between the abutment a and the abutment a, or between the abutment a and the pier, and further with the pier. It is a bridge A as if a floor plate b was laid between the piers.
Not only the bridge A composed of simple beams, but also continuous beams, rigid frame structures, suspension bridges, and slanted long bridges can be targeted.
In this specification, when referring to "between abutments" according to the embodiment of the figure for avoiding complexity, it is not only between abutments a and a but also between abutments a and piers, and between piers and piers. It also means abutment.
The target existing bridge A is a road bridge, a railway bridge, an aqueduct, etc., and its use is not limited.
Further, the material constituting the bridge A can be either concrete or steel.
As will be described later, the method of the present invention corresponds to the conventional concepts and terms such as "repair", "reinforcement", "repair", and "repair" that support the entire bridge A as it is or involve it. It is a construction method that does not.
Therefore, since there is no appropriate expression, the term "regeneration" will be used for the time being, but it is clear that the "regeneration" of the present invention is not limited to the concept of "regeneration" as a conventional technical term in terms of interpretation of rights. Leave it to.
For convenience of explanation, the space below the split support frame 1a group, that is, the water channel portion is referred to as "flow path space 2", and the space above the space is referred to as "planned cutoff space 5".

<2> Manufacture of split support frames.
In order to secure the space of the flow path under the existing bridge, the divided support frame 1a having the flow path space 2 opened inside is manufactured.
The outer shape of the divided support frame 1a exhibits a shape in which both the height and the width are smaller than the height and the width of the lower part of the bridge.
As an example of the split support frame 1a, a split support frame having a flow path space 2 opened inside, facing upward, and forming a convex arch in a direction crossing the central axis of the bridge when installed under the bridge. 1a can be adopted.
In that case, a support or scaffolding, which is an arch-shaped beam, is assembled, and a factory-produced arc-shaped precast concrete, corrugated steel plate, metal foam, or the like is laid on the support frame 1a to manufacture the split support frame 1a.
The cross-sectional area of the flow path space 2 under the split support frame 1a takes into consideration the amount of water flowing down from the mountain side under the bridge A and the amount of trees being washed away when installed under the bridge. decide.

<3> Length of the split support frame.
The length of the divided support frame 1a in the direction crossing the central axis of the bridge is formed to be shorter than the width of the bridge A to be repaired.
The support frame to be installed under the bridge A in this way is manufactured as a split support frame 1a divided in the direction parallel to the central axis of the bridge, or is manufactured at the factory and temporarily placed, so that the slope is steep. It is also possible to repair bridge A in mountainous areas where it is difficult to secure ample land.

<4> Adoption of box culvert.
As the split support frame 1a, a cylindrical box culvert having an external dimension that is smaller in height and width than the height and width of the lower part of the bridge A, which penetrates the flow path space 2 inside, can also be adopted.
Box culverts can be made from precast concrete, steel, or other off-the-shelf products, or can be manufactured near the site.
Other features are the same as the arch-shaped split support frame 1a described above.
The upper surface of the split support frame 1a having any shape is integrated with the solidifying material 4 described later, and is not disassembled even after the solidifying material 4 is cured.

<5> Tension structure of the split support frame.
When the split support frame 1a is installed at the site, it is inconvenient if a gap is generated between the split support frames 1a.
Therefore, it is necessary to pass a steel material through the split support frame 1a and tighten the tension to integrate them as the support frame group 1.
Therefore, in the cross section of each divided support frame 1a, a through hole 12 for inserting a tension material is penetrated at the same position in a direction parallel to the flow path space 2 of the divided support frame 1a.
Alternatively, a bolt or nut structure as used for tension between the segments of the shield tunnel can be adopted so that the adjacent split support frames 1a can be attracted to each other and integrated.

<6> Construction method.
Next, a method of repairing the bridge A using the above-mentioned split support frame 1a will be described.

<7> Integrated with the installation of the support frame group.
The divided support frames 1a having the above-mentioned structure are sequentially installed in the space below the bridge A to be repaired to form the support frame group 1.
For the installation of the split support frame 1a, both the arch type and the box type are installed so that the flow path space 2 inside the arch or the box crosses the central axis of the bridge A.
When the split support frames 1a are sequentially installed under the bridge A and the support frame group 1 of a predetermined extension can be secured, a steel material is inserted into the through holes 12 penetrating through each split support frame 1a and tensioned by a jack to be integrated. Or, the adjacent split support frames 1a are tightly connected with bolts and nuts to integrate them.
As a result, the planned cutoff space 5 becomes a space surrounded by the upper surface of the support frame group 1, the inner side surface of the abutment a facing each other, and the lower surface of the deck b of the bridge A.

<8> Installation of a barrier wall A barrier wall 3 is formed on at least one side or both sides of the bridge A in parallel with the course direction of the road.
The blocking wall 3 does not block the entire space between the abutments a, but is a wall that closes only the valley side, the mountain side, or both sides of the "planned blocking space 5" above the support frame group 1. ..
As the barrier wall 3, for example, a method of stacking thin concrete panels having a width of about 2 meters and a height of about 1 meter on the valley-side end 11 and the mountain-side end of the support frame group 1 can be adopted.
In that case, the PC steel wire and steel rod are penetrated inside and behind the concrete panel, the lower end of the steel wire and steel rod is fixed to the end of the support frame group 1, and the upper end is tensioned to make concrete. The panel can be raised on the end of the support frame group 1.
Since the installation work of the barrier wall 3 as described above is performed from under the bridge A without using the road surface on the bridge A, the traffic on the bridge A is not obstructed.
As described above, the barrier wall 3 is not limited to the case where it is installed on both sides of the bridge A, but may be installed only on the valley side. However, when the barrier wall 3 is installed only on the valley side, it is natural on the mountain side. The slope will function as a barrier 3 on the mountain side as it is.
Therefore, "at least the valley side" means, of course, including the construction of the barrier wall 3 only on the valley side and the construction of the barrier wall 3 on both sides of the valley side and the mountain side.

<9> Filling of consolidation material (Fig. 3)
In the above step, when the blocking walls 3 are set up on the valley side or both sides of the planned blocking space 5, the lower part of the bridge A is the upper surface of the support frame group 1, the inner side surfaces of the abutments a on both sides, and the bridge A. A space surrounded by the lower surface of the floor slab b and the barrier wall 3 can be formed.
The blocking wall 3, the floor slab b, and the planned blocking space 5 surrounded by the upper surface of the support frame group 1 are filled with the known binder 4.
The filling height is up to the lower surface of the floor slab b of the bridge A, or up to the height at which the floor slab b is buried.
As the solidifying material 4, a known material known as a lightweight filling material can be used as described later.
Since such a consolidation material 4 is fluidized, it is possible to fill the inside of the planned blocking space 5 which is surrounded by opening a part of the blocking wall 3 by using a filling pipe.
When horizontal beams are arranged vertically and horizontally on the lower surface of the bridge A, a filling hole is opened in the deck b of the bridge A, not from the blocking wall 3, in the space directly under the bridge A, to that point. It is also possible to arrange a filling pipe for filling.
Since the supply work of the binder 4 can be performed from the surrounding ground space other than the bridge A without using the road surface on the deck b of the bridge A, the traffic on the bridge A is obstructed. Never.
Before filling, various known preliminary works generally performed before the supply of the consolidation material 4, such as laying a waterproof sheet on the ground surface, spraying mortar, and placing anchor bolts, are performed.

<10> Supporting the bridge with a consolidation material By this step, the entire lower part of the bridge A surrounded by the upper surface of the support frame group 1, the blocking wall 3, the inner side surfaces of both abutments a, and the lower surface of the deck b. If the binder 4 is filled in, it will solidify after a certain period of time.
Then, the entire load of the bridge A is received not by the abutment a or the pier but by the binder 4 located below the abutment a.
That is, ignoring some and all of the bearing capacity obtained by the abutment a and piers, the deck b and the dead load of snowfall, the live load of passing vehicles, and the horizontal during an earthquake are mainly composed of the block of the consolidation material 4. It will be loaded.
Therefore, not only the bridge A having a simple beam structure but also continuous beams, rigid frame structures, suspension bridges, and slanted long bridges can be targeted.
In addition, it can be adopted as a basic replacement measure or a rehabilitation measure, rather than a temporary repair of a part of the dilapidated bridge A.

<11> Type of consolidation material As the consolidation material 4 to be filled, a lightweight consolidation can be adopted.
The lightweight embankment is a material used to lighten the embankment such as roads and reduce the load applied to the ground.
As the lightweight filling material, a styrofoam block called EPS, a bubble-mixed lightweight soil called FCB, a urethane foam lightweight soil, a foamed bead-mixed lightweight soil, and the like are known, and these are adopted.
In addition to these, super sol, coal ash, granulated slag, etc. are known, and they can also be adopted.

<12> Widening of the bridge.
The above description is a construction method in which the lower space of the bridge A is filled with the solidifying material 4 to support the entire bridge A.
The construction method of the present invention can also be adopted when widening the width of the bridge A as one of the regeneration measures.
In that case, the end portion of the support frame group 1 is installed in a state of projecting to the outside of the bridge A in a plan view.

<13> A barrier is constructed at a distant position. (Fig. 4)
A blocking wall 3 is erected and constructed on the overhanging end portion 11 of the support frame group 1 overhanging to the outside of the bridge A in a plan view.
Alternatively, the barrier wall 3 is installed vertically or slightly inclined so as to be in contact with the overhanging end portion 11.
Since the end of the support frame group 1 projects outward from the bridge A in this way, the upper end of the barrier wall 3 is located outside the position of the bridge A balustrade before repair.
In that case as well, as in the above method, since the lower portion of the barrier wall 3 is placed on or in contact with the end portion 11 of the support frame group 1, the flow path space 2 is below the support frame group 1. It is secured.
Then, the solidifying material 4 is filled in the entire lower part of the bridge A surrounded by the support frame group 1, the blocking wall 3, the inner side surfaces of both abutments a, and the lower surface of the deck b. If the end plate formwork and the end plate blocking wall 3 are provided at the end portion in the shape of a sleeve wall toward the road side, the binder 4 will not flow out from the end portion of the blocking wall 3.
After the solidifying material 4 is filled in the filling space outside the barrier wall 3 and the bridge A balustrade, the upper surface thereof can be paved and the widened portion can be used as a new sidewalk, a shelter, a bus stop, or the like.
When widening the access road other than the bridge A part, a soil retaining wall is constructed on the extension of the barrier wall 3 in the direction of the central axis of the bridge A, that is, in the direction parallel to the shoulder of the current road, and the road is connected to the current road. The binder 4 is filled at intervals.

<14> Envelopment of bridge A. (Fig. 5)
The above description is a construction method in which the solidifying material 4 is filled in the lower space of the bridge A or the overhanging external space to support the entire bridge A.
Further, the construction method of the present invention can also be adopted as a construction method of wrapping the bridge A with the consolidation material 4 as one of the regeneration measures.
Even at that time, the end portion of the support frame group 1 is installed in a state of projecting to the outside of the bridge A in a plan view.

<15> Installation of a barrier.
In the construction method for wrapping the bridge A, the height of the upper end of the barrier wall 3 is stacked up to a position higher than the upper surface of the bridge A and installed.
After that, the consolidation material 4 is filled, and the consolidation material 4 is filled not only to the lower part of the bridge A but also to the side portion thereof and the upper part thereof.
Then, the bridge A before repair is in a state of being completely surrounded not only by the lower portion but also by the side portion and the upper portion by the binder 4.
Then, even if the floor slab of the bridge A is cracked or damaged, it is not necessary to repair it one by one, and it will be completely embedded inside the binder 4, so it should be repaired reliably. Can be done.
The upper surface of the hardened binder 4 is opened as a new road.
In addition, it is possible to prevent the consolidation material 4 from flowing out from the end portion of the barrier wall 3 by providing a tail plate formwork or a tail plate barrier wall 3 in the shape of a sleeve wall toward the road side at the end portion of the barrier wall 3. It is the same as the above-mentioned widening example.

<16> Self-supporting split support frame.
In particular, in the case of an arch-shaped split support frame 1a, both ends of the arch may be fixed at the lower ends of the abutment a at the lower ends, but the load applied to both ends of the arch is large, and the abutment a with respect to the arch load at both ends. It can be assumed that the reaction force of is insufficient.
In that case, the lower ends of the arch-shaped split support frame 1a formed so as to be convex upward are connected by a horizontal chord member to form a self-standing arch-shaped split support frame 1a.
As the chord material, a horizontal material composed of steel material or net material, or a horizontal floor surface can be used.
Even if this type of split support frame 1a is used, the other steps are the same as those in the above embodiment.

A: Bridge A
1: Support frame group 1a: Divided support frame 3: Blocking wall 4: Consolidating material

Claims (1)

In an existing bridge with abutments and abutments, or abutments and piers, or a floorboard between piers and piers.
After opening the flow path space inside between the abutments and the abutments and installing a split support frame divided in the direction parallel to the central axis of the bridge,
Multiple split support frames are formed as an integrated support frame group,
A barrier is formed on the outside of the bridge parallel to the central axis of the bridge.
It is a method of filling the inside of the space surrounded by this barrier wall and the upper surface of the support frame group with a solidifying material.
The outer end of the support frame group and the barrier wall are located away from the outside of the bridge in a plan view.
With the barrier wall resting on or in contact with the end of the support frame group,
And with the barrier wall securing the flow path space under the support frame group ,
And the height of the upper end of the barrier is set higher than the upper surface of the bridge.
It is characterized by filling the inside of the space surrounded by this barrier and the upper surface of the support frame group not only to the lower part of the bridge but also to the side and upper part and wrapping the bridge with the solidifying material. ,
How to repair a bridge.

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