JPS6364565B2 - - 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 are commonly used to form the road surfaces of road bridges and the like 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 load.

Incidentally, in recent years, with the aging of such concrete floor slabs, the number of floor slab renovations, that is, floor slab replacement work, has been gradually increasing.
When performing this replacement work, if the deck is the non-synthetic girder deck mentioned above, the main girder itself has sufficient strength, so the replacement work will be carried out in stages while handling traffic using methods such as one-sided 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 turning, it was necessary to construct a so-called emergency bridge over the replacement work section, or to secure a detour and branch out accordingly. Work was being carried out to replace the floor slabs while managing traffic through temporary road construction and other methods.

However, in such conventional methods, even when constructing the emergency bridge, it is a fairly large-scale construction work that straddles the replacement work section, which requires a great deal of effort and expense. However, there were problems such as it was often difficult to secure a detour, and in any case, there was a strong desire for some kind of immediate solution.

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 aim is to provide a method for replacing composite girder slabs that can be used.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in Figures 1 to 4, the method for replacing composite girder decks according to the present invention involves closing the old deck slabs 2 on the main steel girders 1 and 1 to traffic for a certain period, for example, at night. Only the section L is removed to the extent that the replacement work of the intended section can be completed, and after that removal, concrete slabs 3, 3, such as a known combo slab, manufactured in advance at a factory etc. are laid. At the same time, the necessary amount of joint concrete 4 is poured between the concrete slabs 3, 3, and the main girders 1,
A new floor slab 6 having a composite girder slab structure almost the same as the old floor slab 2 is formed by performing necessary joint treatment such as pouring concrete 5 on the upper flanges 1a and 1a of 1. And this new floor slab 6 and old floor slab 2
As shown in FIG. 4, between the end surfaces 6a, 2a facing each other, a plurality of axial force transmitting devices 8 consisting of hydraulic jacks etc. are set via bearing plates 7, 7. Pressure is applied to the end surfaces 6a, 2a in a direction to separate them from each other, thereby applying stress in the axial direction to both the old and new floor slabs 6,2. Furthermore, as shown in the figure, a lining plate 9 for vehicle running is passed over both the old and new floor slabs 6, 2 to complete the replacement.
After the joint concrete 4, 5, etc. have cured, the vehicle is opened to traffic and allowed to run on the lining board 9. In this way, traffic is temporarily stopped at night when traffic volume is low, and the floor slabs in a certain section are replaced using the method described above, and this process is repeated one after another.

By the way, when implementing the construction method according to the present invention, the most important step is the treatment of the section that forms the gap A between the old and new slabs 6 and 2, but this section does not have any concrete slabs at all during construction. Therefore, the cross section is only for the main girders 1 and 1, and therefore,
Stress is concentrated on the main girders 1, 1 in this section, and the main girders 1, 1 naturally lack strength. As for this process, in this construction method, both the old and new floor slabs 6,
A plurality of axial force transmission devices 8 consisting of hydraulic jacks or the like are set between the two to apply pressure in the direction of separating both end surfaces 6a, 2a from each other, so that they act on both the new and old deck slabs 6, 2 respectively. Particularly, the axial direction (horizontal direction) component of the stress caused by The lack of strength in 1,1 will be resolved. That is, due to the action of each axial force transmission device 8 set between the floor slabs 6 and 2, even the section of the gap A where no floor slab exists has a cross-sectional structure similar to that of a composite girder slab in terms of strength. Therefore, even if the lining plate 9 is passed across the gap A and the vehicle is run on it as shown in the figure, it can sufficiently withstand the repeated loads etc. exerted by the running vehicle or the like.

The floor slab axial force that is transmitted to each other from the end faces 6a, 2a of both the old and new floor slabs 6, 2 via the axial force transmitting device 8 can be partially reduced by setting a large number of the transmitting devices 8 at equal intervals. It is desirable to take care to make it as uniform as possible without concentrating on it, and in this case, it is also necessary to consider workability. Therefore, as long as this axial force transmission device 8 satisfies these points, in addition to the hydraulic jack shown in the embodiment, a mechanical device that can adjust the spacing between the bearing pressure plates 7, 7 using a screw mechanism or the like may be used. It can also be a structural thing.

Also, the gap between the old and new floor slabs 6 and 2, that is, the gap A
Although it depends on the size of the axial force transmission device 8, it is desirable to make it as narrow as possible in order to reduce the degree of stress concentration on the main girders 1, 1. Since the joint concrete 4 and 5 will be used as a road surface within a relatively short period of time, ultra-early strength concrete is used.

As described in detail above, in the present invention, a certain section of the old deck slab on the main girder is removed, a concrete slab is then laid to form the deck slab, and this floor slab and the old slab are connected. An axial force transmitting device is set between the mutually opposing end surfaces, and pressure is applied by this axial force transmitting device in a direction in which both end surfaces are separated from each other, and a lining for vehicle running is installed on both the old and new deck slabs. Because it is characterized by passing the board,
It has excellent advantages such as being able to fundamentally eliminate the conventional means of traffic management, such as securing detours and constructing emergency bridges, which require a great deal of time and effort, resulting in extremely large economic effects. There is.

[Brief explanation of drawings]

The figures are shown to explain one embodiment of the construction method according to the present invention. Figures 1a and b are partially sectional side views and plan views of the composite girder deck, and Figure 2 is Figure 1a. FIG. 3 is a cross-sectional view taken along the line - of FIG. 1b, and FIG. 4 is a cross-sectional view of the main part. 1...Main girder, 2...Old floor slab, 2a...End face, 3
... Concrete slab, 4, 5 ... Joint concrete, 6 ... New floor slab, 6a ... End surface, 7 ... Bearing plate, 8 ... Axial force transmission device, 9 ... Lining plate, A ...
…gap.

Claims (1)

[Claims] 1. A certain section of the old deck slab on the main girder is removed, and then a concrete slab is laid to form a deck slab, and the end faces of this slab and the old slab are spaced apart from each other. The present invention is characterized in that an axial force transmitting device is installed to transmit stress in the axial direction between the old and new floor slabs by applying pressure in the direction of A method for replacing composite girder slabs on road bridges, etc.