JPH035442B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for replacing composite girder slabs forming the road surface of road bridges and the like.

Concrete deck slabs that form the road surface of road bridges, etc. include composite girder deck slabs and non-synthetic girder deck slabs. The former composite girder deck consists of a deck and a steel main girder that supports the deck, and has a structure that resists the loads of moving vehicles, etc., while the latter non-synthetic girder deck The structure is such that the strength of the main girder itself can withstand the above-mentioned live load.

Incidentally, in recent years, as such concrete floor slabs become obsolete, renovation of the floor slabs, that is, work to replace the floor slabs, is gradually becoming more common.
When carrying out this replacement work, if the deck is the non-synthetic girder slab mentioned above, the main girder itself has sufficient strength, so the replacement work will be carried out one-way while managing traffic using methods such as one-way traffic. However, in the case of composite girder decks where the deck slab and the main girder supporting it are integrated to resist loads, it is not possible to replace the deck due to the unique structure of the composite girder deck. Naturally, it is expected that there will be problems with the strength of the main girder at times, and for this reason, it is extremely difficult to perform floor slab replacement work while the building is open to traffic. Therefore, in the past, unless the site had sufficient width for repeated construction, it was necessary to construct a so-called emergency bridge over the replacement work section, or to secure a detour and create a branch road accordingly. Work to replace the floor slabs was being carried out while dealing with traffic using temporary construction and other means.

However, in such conventional methods, even if the emergency bridge is constructed, it is a fairly large-scale construction work that straddles the replacement work section, which requires a great deal of effort and cost. However, there are problems such as it is often difficult to secure a detour, and in any case, there is a strong desire for measures that can solve these problems.

The present invention has been made in consideration of the above points, and makes it possible to fundamentally eliminate fairly large-scale traffic management methods such as securing detours and constructing emergency bridges that require a great deal of effort and expense. The purpose of this project is to provide a method for replacing composite girder deck slabs.

Hereinafter, the present invention will be explained in detail based on an embodiment shown in the drawings.

First, the basic concept when implementing the construction method according to the present invention will be explained with reference to FIGS. 1 and 2. When replacing composite girder decks, the problem is ensuring the strength of the steel girders. In other words, the steel girder after removing the old deck slab will not have enough strength to withstand live loads such as vehicle traffic. Therefore, in the present invention, a construction method is adopted in which half of each side is replaced, and in this case, as shown in FIG. Therefore, this middle girder 3 is considered to be a non-synthetic girder, and reinforcing steel wire 5 such as wire is stretched in order to compensate for the lack of strength, and a support device 6 that also serves as a steel wire support and a reaction force receiver is attached to the middle girder 3. The feature is that the inner girder 3 is attached to the inner girder 3 and a load is applied in the opposite direction in advance to reinforce it to the same level of strength as the outer girder 1, which is a composite girder.

Next, specific examples shown in FIGS. 3 to 6 will be described.

Figures 3a to 3g are process diagrams showing the steps for replacing the deck slab. First, as shown in Figure a, each steel girder (outer girder 1, 2 After assembling the scaffolding 7 on the lower side and side of the inner girder 3), a connecting girder 8a connecting both girders 2 and 3 is installed between the outer girder 2 and the middle girder 3, and a connecting girder 8a on the upper part of this connecting girder 8a is installed. Install additional girders such as support girder 8b to support the floor slab. These additional girders will be installed so that they can be used as permanent girders like the other girders.

Next, holes 10 for bolt insertion are drilled near the girder ends of the middle girder 3, that is, near the piers 9 of the middle girder 3 as shown in FIGS. 4a and 4b. Anchor fittings 11 for fixing the ends of reinforcing steel wires 5 of the middle girder are bolted. This anchor fitting 11 is also bolted to the vicinity of the other end of the middle girder 3 in the same manner. In this case, both anchor fittings 11 will be attached so as to face each other. As shown in FIGS. 5a and 5b, a specific example of the structure of this anchor fitting 11 is such that the main body 3a is sandwiched from both sides along the main body 3a of the middle girder 3 and the lower flange 3b perpendicular to the main body 3a. A pair of L-shaped plates 11a, 11a are formed, a contact plate 11b is applied to the lower surface of the lower flange 3b, and a steel wire insertion hole 11c is welded to the contact plate 11b in the center.
The bearing plate 11d and the reinforcement rib 11e are configured to integrate and reinforce the bearing plate 11d and the contact plate 11b.
2, it is integrally fixed to the middle girder 3.

After the anchor fittings 11 are attached as described above, the support device 6 is then attached to the middle girder 3. The mounting position and the number of support devices 6 depend on the length of the middle girder 3, but preferably one in each of the four equal parts of the length l of the middle girder 3, as shown in FIG. It is best to install 3 of them. Figure 6a,
b shows a specific configuration example of this support device 6, which includes a horizontal plate 6a that comes into contact with the lower surface of the lower flange 3b of the middle girder 3 and extends in the longitudinal direction of the lower flange 3b; A horizontal member 6b made of a channel material arranged in the horizontal direction and sufficiently longer than the width of the lower flange 3b; one end is attached to the upper side of both ends of this horizontal member 6b, and the other end is attached to the lower surface of the upper flange 3c. Toban 6
a pair of upper inclined frames 6c disposed in such a manner as to abut each other via c′ and sandwich the main body portion 3a;
6c, and a pair of lower inclined frames 6d, one end of which is attached to the lower side of both ends of the horizontal member 6b, and the other end of which is converged so as to intersect on a vertical line segment along the cross section of the main body portion 3a. , 6d, and a pair of reinforcing inclined frames 6e, one end of which is attached to the lower surface of both ends of the horizontal plate 6a at a position 90° different from the inclined frame 6d, and the other end is welded to the convergence position of the inclined frame 6d.
6e, the reinforcing inclined frames 6e, 6e, and the lower inclined frames 6d, 6d are provided so as to be slidable in the vertical direction, which is the central axis direction of the inverted pyramid, and engage the steel wire 5 at the tip. A movable strut 6g having an engagement groove 6f, and a hydraulic jack 6h disposed between the base end of the movable strut 6g and the horizontal plate 6a.
and a positioning member 6i provided on the lower flange 6b of the support device 6 with respect to the lower flange 6b,
6j. An adjustment nut 6k is screwed onto the movable column 6g, and one of the upper inclined frames 6c, 6c is fitted with bolts and nuts to facilitate attachment and removal of the support device 6 to the middle girder 3. 6n
It can be detachably attached.

Once the support device 6 with such a configuration is attached to a predetermined location on the middle girder 3, one end of the steel wire 5 is fixed to the anchor fitting 11 at one end of the girder, and then the other end of the steel wire 5 is fixed to the anchor fitting 11 at the end of the other girder. Steel wire insertion hole 1 of anchor fitting 11
1c, the steel wire 5 is engaged with the engagement groove 6f at the tip of the movable strut 6g, and the steel wire 5 is further pulled in to the extent that there is no slack, and the other end is connected to the anchor fitting 11. Keep it fixed.

After completing the work of tensioning the steel wire 5 in this way, the hydraulic jack 6h is then set, the rod is extended and the movable column 6g is pushed down to tension the steel wire 5, and in this state the nut 6k is tightened. is rotated to fix the movable support column 6g, thereby applying a load in the opposite direction to the middle girder 3 in advance, thereby substantially reinforcing the middle girder 3. Here, the tension pipe embedding of the steel wire 5 is performed using hydraulic pressure. For example, hydraulic jack 6
A load cell or the like may be interposed between h and the movable support 6g.

After completing the reinforcing work on the middle girder 3 as described above, next, as shown in Figure 3b, the protective fence 13 is set up to restrict traffic on one side, and then as shown by the chain line in the figure, One side of the width deck is scooped out, then the dowels are modified and reinforced as necessary, and reinforcing material 1 is installed on the upper flanges of the middle girder 3 and outer girder 2.
4 to reinforce its upper flange.

Next, as shown in Fig. 3c, a precast deck slab 15 for a composite deck slab that has been produced in advance at a factory, etc. is erected, and on-site reinforcing bars 16 are set, and joint concrete is concreted using early-strengthening concrete. 1
7 is poured, and the precast deck slab 15 and the outer girder 2 are integrated. Further, as shown in Figure d, after concrete is placed for the ground cover, asphalt pavement 18 is applied.

After the one-side width floor slab of the old floor slab 4 is replaced by a predetermined length in this way, the remaining one-side width floor slab is replaced in the same manner as described above. That is,
As shown in Figure d, there is a protective fence 1 on the side of the new deck slab that has been replaced.
3', traffic switching regulations are carried out, and then the remaining one-side width floor slab is cleared out as shown by the chain line in Figure e, and the dowels are modified and reinforced as necessary. Further, reinforcing members 14' are provided on the upper flanges of the inner girder 3 and the outer girder 1, respectively, to reinforce the upper flanges.

Next, as shown in Figure f, the precast floor slab 15'
Further, on-site reinforcing bars 16' are set, joint concrete 17' is poured, and the precast slab 15' and the outer girder 1 are integrated. Furthermore, as shown in Figure g, joint concrete 19 on the middle girder 3 is formed by pouring ultra-fast hardening concrete, and after both precast slabs 15, 15' and the middle girder 3 are integrated with each other, Reinforcing materials for the girder 3, ie, steel wires 5, support devices 6, etc., are removed, and after concrete is placed on the ground cover, asphalt pavement 18' is applied to complete the replacement work process between the ends of the girder. Then, by sequentially repeating the above-mentioned work steps, the entire area of the scheduled replacement section is replaced.

In the embodiment, the support device 6 for the steel wire 5 for reinforcing the middle girder 3 is shown as having a movable column driven by a hydraulic jack, but in short, the steel wire 5 is pushed down and tensioned. Any configuration can be used as long as it has a function that allows the configuration to be performed, and is not limited to the embodiments.

As detailed above, in the method of replacing composite girder decks according to the present invention, the middle girders that serve as edge cuts after the removal of the old deck are reinforced in advance with steel wires, support devices, etc., and then replaced one side at a time. This construction method fundamentally eliminates the need for fairly large-scale traffic management methods, such as securing detours and constructing emergency bridges that require a great deal of effort and expense, as required with conventional construction methods. The actual reinforcing means are relatively simple and reusable, such as support devices and steel wires, so
It has a variety of effects, including excellent workability and contributing to reduced construction costs.

[Brief explanation of the drawing]

Figures 1 to 6 show one embodiment of the present invention. Figures 1 and 2 are model diagrams showing the basic concept of the construction method according to the present invention, and Figures 3 a to g are floor slabs. Figures 4a and 4b are schematic side views showing the mounting position of the anchor fittings, Figures 5a and b are front and side views showing the structure of the anchor fittings, and Figure 6a is a process diagram showing the replacement procedure. and b are front and side views of the support device. 1, 2...External girder, 3...Medium girder, 4...Old floor slab,
5... Steel wire for reinforcement, 6... Support device, 11... Anchor fittings, 15, 15'... Precast floor slab,
17,17'...Joint concrete, 18,1
8'...Asphalt pavement, 19...Joint concrete.

Claims (1)

[Scope of Claims] 1. An intermediate girder that also extends in the bridge axis direction is provided between the outer girders that extend in the bridge axis direction, and each of these girders and the concrete deck slab thereon are integrally activated. A method for replacing a composite girder deck, which has a structure that resists loads, which includes: (a) arranging reinforcing steel wires extending along the longitudinal direction of the middle girders below the middle girders; (b) A step of fixing both ends of the steel wire near the girder ends of the middle girder; a step of attaching a support device having a movable strut; (c) tensing the steel wire by pushing down the movable strut while engaging the movable strut of the support device at at least one location between both fixing points of the steel wire; (d) A method for replacing composite girder decks in road bridges, etc., comprising the steps of: (d) replacing the one-side width deck between the girder ends of each girder, and then replacing the remaining one-side width deck.