JP2003041516A - Integral structure of upper and lower parts of continuous girder bridge and method of constructing it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple integral structure of the upper and lower parts of a continuous girder bridge with excellent load and earthquake resistance, and facilitating adjustments of construction errors for excellent construction properties, and a method of constructing it. SOLUTION: A pier 3 is reinforced and concrete is placed up to approximately the upper part thereof. The lower part of a branching girder and the lower part of the overhanging girder of the branching girder are framed into a box shape, which is then placed on the upper surface of the concrete 6 to coincide with the side faces of the pier 3. The sides of the lower part of the branching girder are fastened to the sides of the lower part of the overhanging girder via fastening means to construct a lower frame structure. Thereafter, concrete is placed to approximately the upper part of the lower frame structure so that the lower frame structure is embedded into the pier 3. After the concrete has hardened, the lower part of the overhanging girder, the upper end of the lower part of the branching girder, the upper part of the overhanging girder which serves as the joint of the upper construction, and the upper part of the branching girder are fastened to one another via the fastening means. Concrete is placed inside the lower frame structure and the upper frame structure which is formed at the top end of the pier 3 and constructed of main girders 1 and cross girders 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous girder bridge upper and lower integrated structure which is simple, has excellent load-bearing capacity and earthquake resistance, and is easy to construct, and a construction method thereof.

[0002]

2. Description of the Related Art Conventionally, the upper and lower integrated structures of a continuous girder bridge, in which superstructures are continuous over multiple spans, make the superstructure and substructure rigid by embedding them up to the top of the main girder at the top of the pier. The structure was commonly used.

[0003]

However, with the structure in which the top of the main girder is embedded in the bridge pier, it is difficult to maintain the accuracy when installing the main girder on the pier, and the installation work requires a platform for work. Had to be temporarily placed. Further, when the main girder is embedded in the bridge pier, the concrete of the rigid connection portion interferes, and the mobile formwork device generally used for constructing the floor slab cannot be used.

The present invention has been made in view of the above circumstances, and is an integrated upper and lower structure of a continuous girder bridge that is simple and has excellent load-bearing capacity and earthquake resistance, and is easy to adjust construction errors, and has excellent workability. The purpose is to provide a construction method.

[0005]

The invention according to claim 1 is
A plurality of main girders that make up the superstructure of a continuous girder bridge, and an upper and lower integrated structure of a continuous girder bridge that rigidly connects a pier made of reinforced concrete. A lower frame structure composed of a branch girder joined to the lower side of the lower flange and a frame-shaped projecting girder connecting between the branch girders joined to the lower part of the cross girder located on the side surface of the pier, A plurality of the main girders located at the top end of the pier and an upper frame structure composed of a pair of the transverse girders are integrated by being fastened via a joint, and the upper part The inside of the frame structure and subframe structure is characterized by being filled with concrete piers to form a composite structure.

The invention according to claim 2 is characterized in that the upper end of the cross girder has a space necessary for a movable formwork apparatus for floor slab construction to pass through.

According to a third aspect of the present invention, the upper frame structure and the lower frame structure are provided with stud dowels, and the flanges of the transverse girder and the projecting girder are arranged on a pier. It is characterized in that a fixing means for fixing the existing main rebar is provided.

According to a fourth aspect of the present invention, concrete is placed up to substantially the upper part of the pier where the reinforcement is finished, and then the lower frame structure formed by the overhanging girder of the transverse girder and the branch girder of the main girder is formed. After placing it on the upper part of the bridge pier and fixing concrete again, the branch girder and the main girder constituting the upper frame structure, the projecting girder and the transverse girder constituting the upper frame structure are connected via fastening means. It is characterized in that concrete is placed inside the upper frame structure and the lower frame structure while being fastened together.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the upper and lower integrated structures of a continuous girder bridge according to the present invention will be described below with reference to FIGS.

As can be seen from FIG. 1, the main girder 1 in which the superstructure is continuous over multiple spans is arranged at the top 3a of the pier 3, and the girder 4 also located at the top 3a of the pier 3.
Are vertically provided so as to cooperate with the main girder 1 at a position corresponding to the side surface 3b of the pier 3.

As shown in FIG. 2, the main girder 1 is erected vertically so as to connect a plurality of piers 3. In the present embodiment, the main girders 1 forming a pair are erected parallel to each other with a spacing substantially similar to the lateral width of the pier, but the present invention is not limited to this, and a plurality of main girders 1 are erected in parallel. You may.

A branch girder 2 is provided below the main girder 1 so as to project to the bridge pier 3. The branch girder 2 is composed of a branch girder upper part 2a directly provided on the main girder 1 and a branch girder lower part 2b fastened to the branch girder upper part 2a through fastening means, and has the same spacing as the pier 3. It is located in. Further, the lateral width of the branch girder 2 is substantially the same as the width of the pier 3, and the stud dowels 7 are provided on both sides of the web, so that the concrete 6 that constitutes the pier 3 is formed.
And the fixing strength of the above (see FIG. 1). The pier 3 is made up of the reinforcing bar 3b and the concrete 6
It is made of reinforced concrete.

The transverse girders 4 are arranged in pairs at the top portion 3a of the pier 3 and on both side surfaces 3b, respectively. The transverse girders 4 are arranged so as to connect the main girders 1 to each other. Vertical and vertical. Also, the main girder 1
The height of the top end 1a of the floor and the height of the top end 4b of the cross girder 4 are set so that the movable formwork device, which is a well-known technique developed for constructing the floor slab 10, can pass through the space. Are provided (see FIG. 2).

Further, as shown in FIG. 3, notches 4a are provided at the upper corners of the cross beam 4,
The main girder 1 is vertically mounted on the cutout portion 4a. Further, stud dowels 7 are provided on one surface of each of the pair of cross girders 4a facing the web (see FIG. 3).

The lower flange of the cross girder 4 is provided with fixing means such as fixing metal fittings (not shown) for fixing the main reinforcing bar 3b arranged in the pier 3 as shown in FIG. Without being limited to this, a through hole may be previously provided in the lower flange of the cross beam 4 at a position coaxial with the arrangement position of the main reinforcing bar 3b, and the through hole may be inserted to fix the through hole.

At the lower part of the transverse girder 4 forming a pair, an overhanging girder upper portion 5a provided directly under the transverse girder 4 and an overhanging girder lower portion 5b connected to the overhanging girder upper portion 5a. The girder 5 is attached. The side portion of the protruding girder lower portion 5b and the branch girder lower portion 2b attached to the main girder 1 are connected to each other to form a box-shaped lower frame structure 8.

A lower flange is provided on the inner side of the lower end of the abdominal plate in the lower portion 5b of the projecting girder, and fixing means such as a fixing fitting (not shown) for fixing the reinforcing bar 3b arranged in the pier 3 is provided. Not limited to this, the horizontal beam 4
The flange may be provided with a through hole in advance at a position coaxial with the arrangement position of the main reinforcing bar 3b, and the through hole may be inserted to fix the flange.

As described above, the lower frame structure 8 composed of the lower portion 5b of the projecting girder and the lower portion 2b of the branch girder has the pier 3
Of the main girder 1 which is embedded in the top part of the lower girder structure 8 and the upper end of the lower frame structure 8 serves as a joint, and is fastened to the overhanging girder upper part 5a of the transverse girder 4 through fastening means 9, respectively. It As a result, the upper frame structure 11 formed by the main girder 1 and the lateral girders 4 formed at the top end of the bridge pier 3 is integrated to form an upper and lower integrated structure. These lower frame structure 8 and upper frame structure 11
Since the concrete 6 of the bridge pier 3 is embedded inside, the so-called composite structure is formed in the upper and lower integrated structure.

A construction method of the upper and lower integrated structure having the above-mentioned structure will be described below. First, after arranging the piers 3, the concrete 6 is placed almost up to the top. Next, the branch girder lower part 2b and the branch girder overhang girder lower part 5b are made into a box-shaped frame, and are arranged on the upper surface of the concrete 6 so as to coincide with the side surface 3a of the pier 3. At this time,
The bottom portion of the projecting girder lower portion 5b is fixed by using a through hole or a fixing metal fitting so that the reinforcing bar 3b arranged on the pier 3 penetrates.

Next, the lower frame structure 8 is constructed by fastening the side portions of the branch girder lower portion 2b to the side portions of the projecting girder lower portion 5 through fastening means 9. The lower portion 5b of the projecting girder and the lower portion 2b of the branch girder may be assembled as the lower frame structure 8 and then placed on the upper surface of the concrete 6.

After that, the concrete 6 is poured to almost the upper part of the lower frame structure 8 so that the lower frame structure 8 is embedded in the bridge pier 3. After the concrete 6 is hardened, the upper ends of the overhang girder lower part 5b and the branch girder lower part 2b are joined to the overhang girder upper part 5a and the branch girder upper part 2 which are joints on the superstructure side.
A is fastened via the fastening means 9. Finally, concrete 6 is placed inside the lower frame structure 8 and the upper frame structure 11 formed at the top end of the bridge pier 3 and composed of the main girder 1 and the cross girder 4, and at the same time, the pier 3 Also, concrete 6 is cast until it reaches the top.

According to the above-mentioned structure, the main girder 1 and the transverse girders 4 are fastened using the frame 8 embedded in the top of the pier 3 and the fastening means 9, and the fastening portions are made of concrete 6 struck. The structure is not only embedded and integrated, but also a rigid structure with a composite structure is formed, so that a simple and rational structure can be obtained.

Further, since the reinforcing bar 3b of the pier 3 is arranged inside the frame 8 and is cast by the concrete 6, the reinforced concrete in the rigid connection portion has an enhanced confining effect, and has load-bearing and seismic resistance. It has become possible to improve.

Since the frame 8 is first arranged on the top of the bridge pier 3 and the main girder 1 and the cross girder 4 are fastened to the frame 8, sufficient precision adjustment can be performed when the frame 8 is installed. It is possible to improve the property.

Since it is not necessary to embed the main girder 1 itself in the pier 3, it is possible to provide a sufficient space between the top end 1b of the main girder 1 and the top end 4b of the transverse girder 4, and the floor slab It becomes possible to use the inner surface formwork device generally used for construction, and it becomes possible to improve construction efficiency.

The tensile force due to the bending moment from the superstructure can be smoothly transmitted from the main girder 1 and the cross girder 4 to the reinforcing bar 3b through the stud dowel 7.

[0027]

According to the invention as set forth in claim 1, it is composed of a plurality of branch girders joined to the lower side of the lower flange of the main girder and an overhang girder joined to the lower part of the transverse girder. The lower frame structure and the upper frame structure composed of the main girder located at the top end of the bridge pier and the pair of transverse girders are integrated by being fastened via fastening means, The inside of the pier is filled with pier concrete to form a composite structure, which makes it possible to create a simple and rational rigid connection structure, and the reinforced concrete of the rigid connection part has a higher confined effect. It is possible to improve load resistance and earthquake resistance.

According to the second aspect of the present invention, since the space required for the movable formwork device for floor slab construction to pass through is provided at the upper end of the cross girder, the workability of the entire bridge is improved. It is possible to shorten the construction period.

According to the third aspect of the present invention, the upper frame structure and the lower frame structure are provided with stud dowels, and the flanges of the transverse girder and the projecting girder are disposed on the pier. Since there is a fixing means to fix the main rebar, the tensile force due to the bending moment from the superstructure can be smoothly transmitted to the rebar from the main girder and cross girder via the stud dowel. And

According to the invention as set forth in claim 4, the lower frame structure is arranged on the upper part of the pier, and after concrete is placed and fixed again, the main girders and the lateral girders constituting the upper frame structure are fixed. Since the fastening is performed through the fastening means, sufficient accuracy adjustment can be performed when the frame is built, and thus workability can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall condition of an upper and lower integrated structure of a continuous girder bridge according to the present invention.

FIG. 2 is a diagram showing details of an upper and lower integrated structure of a continuous girder bridge according to the present invention.

FIG. 3 is a diagram showing a transverse girder of an upper and lower integrated structure of a continuous girder bridge according to the present invention.

FIG. 4 is a diagram showing a main girder of an upper and lower integrated structure of a continuous girder bridge according to the present invention.

[Explanation of symbols]

1 main girder 1a Crown 2 branch girders 2a Upper part of branch girder 2b Lower part of branch girder 3 piers 3a side 3b rebar 4 horizontal girders 4a Cutting 4b Crown 5 overhang girder 5a Overhang girder upper part 5b Overhang girder bottom 6 concrete 7 Stud Gibel 8 Lower framework structure 9 Fastening means 10 floor slab 11 Upper framework structure

Claims (4)

[Claims] 1. An upper and lower integrated structure of a continuous girder bridge in which a plurality of main girders constituting the superstructure of the continuous girder bridge and a pier made of reinforced concrete are rigidly connected, and projecting inside the pier. A branch girder joined to the lower side of the lower flange of the main girder, and a frame-shaped projecting girder connecting the branch girders joined to the lower part of the cross girder located on the side surface of the pier. The lower frame structure, the upper frame structure composed of the plurality of main girders located at the top end of the bridge pier, and the pair of transverse girders are integrated by being fastened via joints. In addition, the upper and lower integrated structures of a continuous girder bridge, characterized in that a concrete structure is filled inside the upper and lower frame structures to form a composite structure. 2. The upper and lower integrated structure of the continuous girder bridge according to claim 1, wherein the upper end of the cross girder has a space necessary for a movable formwork device for floor slab construction to pass through. Integrated structure of upper and lower parts of continuous girder bridge. 3. The upper and lower integrated structures of the continuous girder bridge according to claim 1, wherein the upper frame structure and the lower frame structure are provided with stud dowels, and flanges of the transverse girder and the overhang girder are provided. The upper and lower integrated structure of a continuous girder bridge, characterized in that it is provided with fixing means for fixing the main reinforcing bars arranged on the pier. 4. After placing concrete up to substantially the upper part of the pier where the reinforcement has been completed, the lower frame structure formed by the overhanging girder of the transverse girder and the branch girder of the main girder is arranged on the upper part of the pier. After placing and fixing concrete again, the main girder that constitutes the branch girder and the upper frame structure,
Upper and lower parts of a continuous girder bridge characterized in that the projecting girder and the cross girder constituting the upper frame structure are fastened via fastening means, and concrete is placed inside the upper frame structure and the lower frame structure. Construction method of integrated structure.