JP3009583B2 - Sequential connection type erection method of precast reinforced concrete slab composite girder bridge. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of successively connecting a precast reinforced concrete slab (hereinafter referred to as a PC slab) to a composite girder bridge.

[0002]

2. Description of the Related Art In a conventional ordinary concrete slab steel girder bridge, the slab functions to transmit a live load of a vehicle or the like to the steel girder.
The steel girders are designed to support live loads and dead loads consisting of the weight of the deck and steel girders. This is called a non-combined digit. On the other hand, a structure in which the PC slab and the steel girder are combined and integrated to support the load is referred to as a composite girder.

As a method of constructing a composite girder bridge in a conventional simple girder bridge, there are two methods shown in FIGS. 5 and 6 below.
FIG. 5 is a side view showing a construction method of a conventional composite girder bridge called a live load composite girder. First, after a steel main girder b is erected between fulcrums a shown in FIG. 5A, a PC floor slab c is placed on the main girder b. (See Fig. 5 (b).) Then, the floor slab c and the main girder b
And the joints d between the adjacent floor slabs c are filled with mortar or the like, and the floor slab c and the main girder b are appropriately integrated via the joining means e (see FIG. 5C). The floor slab may be a cast-in-place reinforced concrete slab instead of a PC slab.

[0004] In this method, the dead weight of the main girder b and the floor slab c, that is, dead life is shared only by the main girder b, and only the live load of the vehicle or the like is installed on the main girder b and the main girder b. Floor slab c
Will be shared by the synthesizing action of On the other hand, FIG. 6 is a side view showing another construction method of a conventional composite girder called a dead load composite girder. According to this method, the main girder b and the floor slab c are integrated by the vent f until they are integrated. The vent f is removed after the composite girder is completed and the dead weight is shared by the main girder b and the floor slab c.

[0005]

The conventional method has the following problems. (1) In the former live load composite girder, since the dead load is shared only by the main girder, the cross section of the main girder becomes large and the material cost increases. (2) The latter dead load composite girder is reasonable as a composite girder, but it requires a vent when erected, which not only increases the construction cost but also makes it impossible to install a vent in a deep valley or the like.

The present invention has been proposed in view of the above-mentioned problems of the prior art. The object of the present invention is to enable a structurally rational design, to reduce construction costs, and to provide a vent. It is an object of the present invention to provide a method of successively connecting a PC girder composite girder bridge that can be installed even in a deep valley where it cannot be installed.

[0007]

In order to achieve the above-mentioned object, according to the present invention, a composite girder bridge composed of a precast reinforced concrete slab and a steel girder is provided by a method of sequentially connecting a PC slab composite girder bridge. Each time one floor slab is installed on a girder, it is combined with a steel girder and partially combined sequentially, and the part where the floor slab and the steel girder are joined in advance is used as a composite cross section and installed later. The weight of the floor slab is shared.

[0008]

[Function] Since the PC slab used in the erection method of the present invention is erected in a state of being produced at the factory and having strength, a composite action is exhibited by installing it on a steel girder and joining it with the steel girder. Therefore, in the portion where the PC slab and the steel girder are combined to form a composite girder, the own weight of the floor slab to be subsequently installed can also be shared as the composite girder. Thus, P
When the two are sequentially combined each time one C slab is installed, it becomes possible to partially share the own weight of the PC slab to the combined girder cross section.

[0009]

FIG. 1 is a side view showing a construction procedure in an embodiment of a method of sequentially constructing a PC deck composite girder bridge according to the present invention. First, a steel main girder 1 is installed between fulcrums 2 shown in FIG. Next, as shown in FIG. 1 (b), the first PC slab, 3A is installed in the center of the main girder 1, and the connection 4 with the main girder 1 is a connection portion between the PC floor slab and the main girder as described later. .
Here, the PC floor slab 3A is integrated with the main girder 1 and can exert a synthesizing action against the subsequent load. Next, as shown in FIG. 1C, the PC slab 3B is installed on both sides of the previously installed PC slab 3A, and is connected to the main girder 1. At this time, in order to share the load as a combined action, the floor slab must have unity in the bridge axis direction, so as shown in FIG.
The joints 5 between the floor slabs are filled with mortar, resin or the like to transmit a compressive load. In this state, the own weight of the next PC floor slab 3C is shared as a composite section.

The PC floor slabs 3 installed in this way are sequentially joined to the main girder 1 and joints 5 between the floor slabs are filled with mortar or resin to function as sequential composite girder, so that the floor slabs to be installed later are provided. Can be partially shared as a composite digit. (Refer to FIG. 1 (e)) In FIG. 2, the state in which the combined cross section in the embodiment shown in FIG. FIG. 2A is a side view showing the final state in the example of FIG. 1, in which PC floor slabs are given symbols 3A to 3E in the order of installation on the main girder 1. FIG. 2B shows a bending moment distribution 6 due to the main girder 1 own weight. FIG.
(C) shows the bending moment distribution 7A of the PC floor slab 3A initially installed due to its own weight. FIG. 2 (d) shows a bending moment distribution 7B of the PC floor slab 3B installed next due to its own weight.

In this moment distribution, a hatched portion 8A
Is a portion shared by the composite cross section of the PC floor slab 3A and the main girder 1 installed earlier. Hereinafter, similarly in FIGS. 2 (e) to 2 (g), the bending moment components shared by the combination of the PC slab and the main girder 1 previously installed and connected to the main girder 1 are represented by hatched portions 8B, Shown at 8C. The bending moment distribution after installation of all the PC slabs is the distribution indicated by 9 in FIG. 2 (h), and the portion shared by the composite cross section is the hatched portion 10. Therefore, according to the construction method of the present invention, the portion of the hatched portion 10 in FIG. 2 (h) may be designed with a synthetic cross section with respect to the load due to the weight of the floor slab, and the steel weight of the main girder 1 can be greatly reduced.

FIGS. 3 and 4 show the first embodiment of the present invention. The main girder 1 is a steel plate welding girder (plate girder) having an I-shaped cross section, and a PC floor slab 3 is installed above the main girder 1. In FIG. 3, as an example of a connecting portion 4 between the PC main girder 1 and the floor slab 3, a box hole 12 provided on the PC floor slab 3 is fitted to a dowel 13 provided on the upper flange of the PC main girder 1. And a box hole 12 made of mortar or resin.
The method for filling is shown. However, in this method, the result of synthesizing the PC slab and the main girder cannot be expected until the hardening of the filler such as mortar or resin, and as shown in FIG.
The method of mechanically connecting the stud bolts 14 provided on the main girder with the nuts 15 in the box holes 12 provided on the PC floor slab 3 enables more efficient installation. In this case, the joints 5 between the PC slabs 3 are filled with mortar, resin, or the like so that a compressive force can be transmitted during the synthesizing operation.

[0013]

According to the present invention, the PC slab and the main girder are successively installed on the main girder and connected to each other, and the main girder and the PC slab are sequentially synthesized. As the weight of the PC slab to be installed on the main girder can be shared in the future, the main girder can finally have a sufficient strength against dead load, which enables rational design in terms of structure and contributes to reduction of construction cost I do.

Further, according to the present invention, since no vent is required, the cost can be reduced as compared with the conventional dead load composite girder, and a bridge can be erected in a deep valley where a vent cannot be installed.

[Brief description of the drawings]

1 (a), (b), (c), (d) and (e) are side views showing the steps of a sequential connection type erection method for a PC slab composite girder bridge according to the present invention.

FIG. 2 is an explanatory view showing a bending moment distribution of a girder in each step of the construction method shown in FIG.

FIG. 3 is a perspective view showing one embodiment of a process of installing a PC floor slab on a main girder in the method shown in FIG.

4 is a longitudinal sectional view showing another embodiment of the installation process of the PC floor slab shown in FIG.

FIGS. 5 (a), (b) and (c) are side views showing steps of an example of a conventional method.

FIG. 6 is a side view showing another example of the conventional method.

[Explanation of symbols]

 1 Main girder 2 Support 3A, 3B, 3C, 3D, 3E PC slab 4 Joint between PC slab and main girder 5 Joint

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Akinobu Kishi 1-1-1, Wadazaki-cho, Hyogo-ku, Kobe-shi, Hyogo Inside Mitsubishi Heavy Industries, Ltd. Kobe Shipyard (56) References JP-A-4-24306 (JP) , A) JP-A-7-197420 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) E01D 21/00 E01D 1/00

Claims (1)

(57) [Claims] 1. A composite girder bridge of a precast reinforced concrete slab and a steel girder, wherein each time one of the floor slabs is installed on a steel girder, the slab is combined with a steel girder and partially and sequentially synthesized to form a slab. A method of successively connecting a precast reinforced concrete slab composite girder bridge, wherein a portion where a steel girder is joined earlier is used as a composite section and the weight of a slab to be installed later is shared.