JP2008274636A - Construction method for truss bridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rational construction method for a truss bridge, reducing the term of construction for a concrete truss bridge. <P>SOLUTION: A precast concrete segment 11 of an upper chord material on which a metal connector 12 connected to a single item diagonal member 31 is projected, a precast concrete segment 21 of a lower chord material on which a metal connector 22 connected to the single item diagonal member 31 is projected, and the single item diagonal member 31 having connecting end parts to the metal connectors 12, 22 at both ends thereof are respectively individually manufactured in advance, and at a construction place, the precast concrete segment 11 of the upper chord member, the precast concrete segment 21 of the lower chord member, and the single item diagonal member 31 are connected to one another. The precast concrete segment 11 of the upper chord member and the precast concrete segment 21 of the lower chord member are connected to the adjacent already constructed upper and lower chord members 10, 20, respectively by PC stretch material to construct the truss bridge. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for constructing a truss bridge.

  A truss is a structure in which an upper chord member and a lower chord member are connected by a large number of diagonal members, and is often used in buildings, beams or girders of structures, bridges, and the like. The upper chord material and the lower chord material are often parallel, but one has a bowed shape. There are bridges in which an upper floor slab is placed on two parallel trusses that are parallel to the left and right, and the upper surface is used as a load surface, and another one that uses a parallel two trusses as side walls and a lower floor slab as a load surface. Examples of the structural material constituting the truss include steel, concrete, and a composite structure in which these are combined.

  For example, steel pipes are used for the truss diagonal, and the lower end of the diagonal is embedded in the lower chord material of the lower concrete structure, and the upper end of the diagonal is embedded in the upper upper chord material made of concrete. A technology to construct a pony bridge with a substantially U-shaped cross-section by installing truss diagonals on both ends of the concrete floor slab that has been constructed, and repeatedly placing the lower chord material and upper chord material concrete by a unit length sequentially. Yes (see, for example, Patent Document 1).

  In this technology, upper and lower chord materials are constructed with cast-in-place concrete and then extended sequentially.

  In addition, there is a technique for overhanging a box-type concrete composite truss bridge whose main girder is made of steel pipe using a construction work vehicle (see, for example, Patent Document 2).

  This technology is also a technology in which upper floor slab concrete and lower floor slab concrete are constructed on-site, and box-type concrete composite truss bridges are sequentially extended and installed.

  Since these truss bridges are constructed with cast concrete on the upper and lower chord materials (or upper and lower floor slabs), there is a problem that requires a long time for construction.

  Also known is a technique of manufacturing a rectangular full-section box-type precast segment using a connecting steel pipe on the main girder web and constructing a bridge by sequentially connecting the segments (see, for example, Non-Patent Document 1). ).

This technology is not a truss bridge but a box-type steel-concrete composite bridge in which the web is formed of steel pipes. In this technique, a segment in which the entire cross section of the box-type bridge is integrated is manufactured by precast, so that the segment member size is large and transportation is difficult.
JP 2003-193424 A (page 3-5, FIG. 1) Japanese Patent Laying-Open No. 2003-193430 (page 2-5, FIG. 1) http: // en. structure. de / photos / index. cfm? JS = 4542 France Bronnet Viaduct (Viaducs du Boulonnais)

  An object of the present invention is to provide a rational truss bridge construction method that shortens the construction period of a concrete truss bridge.

  The truss bridge erection method of the present invention that achieves the above object comprises an upper chord member and a lower chord member made of a precast concrete segment projecting a connecting fitting for connecting to an oblique member, and connecting ends of the connecting fitting at both ends. The upper and lower chord members and the diagonal member are connected to each other in advance, and the upper chord member and the lower chord member are connected to the adjacent existing upper and lower chord members with PC tension members, respectively. It is characterized by erection of a bridge.

  In the construction method of the truss bridge of the present invention, the upper chord material and the lower chord material are made of precast concrete segments having a portable size, and the upper chord material and the lower chord material are provided with connecting members with diagonal materials so as to connect the diagonal materials. However, the segments will be connected in sequence. It is preferable that the diagonal material is made entirely of metal or both ends, and the coupling method, the coupling strength, and the like with the coupling metal are determined according to the axial force applied to the diagonal material. For example, it is performed by flange connection, welding connection, pin connection or the like. If the diagonal material is made of precast concrete, it is only necessary to attach metal connection parts to both ends of the diagonal material. The connecting bracket and the diagonal member may be connected by connecting the protruding reinforcing bars, assembling the formwork at the connecting portion, and placing concrete.

  The upper chord material and the lower chord material are precast concrete segments, and are connected to adjacent existing upper chord material and lower chord material by PC tension materials, respectively.

  In the truss bridge erection method of the present invention, the upper chord material may be integrated with the upper floor slab of the truss bridge, and the lower chord material may be integrated with the lower floor slab of the truss bridge. Further, for example, in a box bridge, both the upper chord material and the lower chord material may be integrated with the upper floor slab and the lower floor slab, respectively. In such a preferable form, construction is further simplified according to the conditions of each truss bridge, which contributes to shortening the construction period.

  According to the present invention, the upper chord material, the lower chord material, and the diagonal material of the truss bridge are manufactured in advance as members of a size that can be transported, and these are assembled while being assembled at the installation location. Compared with the conventional method of construction, the construction period can be significantly shortened. The upper and lower chords can be produced in a factory with good quality control, and excellent products can be obtained. Further, the upper and lower chord members and the diagonal member can be connected by flange connection, weld connection, pin connection, etc., and can be reasonably constructed in a short time. The upper and lower chord members and the diagonal members can be appropriately designed in terms of the structure, dimensions, etc. of the upper and lower chord members and the connecting metal fittings, and since they are embedded in the lower chord member on the precast, an excellent structure is obtained.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIGS. 1-3 show one Embodiment about the construction method of the truss bridge of this invention, and are typical side views of a truss.

  The truss 1 includes an upper chord member 10, a lower chord member 20, and an oblique member 30 that connects the upper chord member 10 and the lower chord member 20. Conventionally, in the concrete truss bridge, the upper chord material 10 (or the upper floor slab) and the lower chord material 20 (or the lower floor slab) have been constructed with on-site cast concrete.

In the present invention, the upper chord member 10 and the lower chord member 20 are individually manufactured as precast concrete segments in advance, and the diagonal member 30 is individually manufactured as an individual diagonal member in advance and assembled at the construction site of the truss bridge.

  As shown in FIG. 1, a connecting metal fitting 12 that is connected to a single diagonal member 31 is projected in advance on a precast concrete segment 11 made of an upper chord material. The connecting metal fitting 12 is structurally connected to the rebar in the precast concrete segment 11 of the upper chord material at the tail end to form an appropriate grading structure, and the protruding end is connected to the end of the single diagonal member 31. is there. For example, a flange connection, a butt welding connection, a welded structure via a sleeve or a sheet metal, a pin connection, and the like.

  The precast concrete segment 21 that is the lower chord material is also provided with a projection 22 in advance that is connected to a single diagonal member 31. The connecting metal fitting 22 is structurally connected to the reinforcing bar in the lower chord material precast concrete segment 21 to form an appropriate grading structure, and the protruding end is connected to the end of the single diagonal member 31. is there. For example, a flange connection, a butt welding connection, a welded structure via a sleeve or a sheet metal, a pin connection, and the like.

  The single diagonal member 31 may be made of steel, for example, a steel pipe, a shaped steel, or the like, and may be made of precast concrete in some cases. The end portion is provided with a metal connecting portion 32 so that it can be easily connected to the connecting fitting 12 of the precast concrete segment 11 made of the upper chord material and the connecting fitting 22 of the precast concrete segment 21 made of the lower chord material. For example, when the single diagonal member 31 is made of precast concrete, metal connection portions 32 are attached to both ends.

  As shown in FIG. 1, the upper chord material precast concrete segment 11 is moved as indicated by an arrow 13 so that its end face 14 is brought into contact with the already-prepared upper chord material 10, and the PC tension material is used as the upper chord material precast concrete segment. 11 is inserted into the upper chord material 10 which has already been constructed, and is tensioned to integrate the precast concrete segment 11 of the upper chord material with the already constructed upper chord material 10. Similarly, the precast concrete segment 21 of the lower chord material moves in the direction of the arrow 23 and is connected to the already-constructed lower chord material 20.

  Next, as shown in FIG. 2, a single diagonal member 31 is inserted between the connection fitting 12 and the connection fitting 22 as indicated by an arrow 33, and both ends thereof are connected to the connection fitting 12 and the connection fitting 22.

  FIG. 3 shows a state where the extension of the truss 1 is completed after the connection of the precast concrete segment 11 of the upper chord material, the precast concrete segment 21 of the lower chord material, and the single diagonal member 31 is completed. The connecting portion 15 between the upper chord material precast concrete segment 11 and the single diagonal member 31 and the connecting portion 25 between the lower chord material precast concrete segment 21 and the single diagonal member 31 are firmly connected by flange connection, welding connection, pin connection or the like. Combined with

  As described above, according to the present invention, it is possible to construct a truss bridge with excellent quality and performance in a short period of time by using precast concrete segments without requiring concrete casting of upper chord material and lower chord material.

  4 to 6 illustrate a cross section of a concrete truss bridge to which the present invention is applied.

As shown in FIG. 4, the upper chord material 10 and the upper floor slab 40 may be formed of an integral precast concrete segment, and as shown in FIG. 5, the lower chord material 20 and the lower floor slab 50 are integral with the precast concrete. It may be formed of segments. As shown in FIG. 6, the upper chord member 10 and the upper floor slab 40, and the lower chord member 20 and the lower floor slab 50 may be formed of a single precast concrete segment.

It is a typical side view of a truss. It is a typical side view of a truss. It is a typical side view of a truss. 1 illustrates a cross section of a concrete truss bridge to which the present invention is applied. 1 illustrates a cross section of a concrete truss bridge to which the present invention is applied. 1 illustrates a cross section of a concrete truss bridge to which the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Truss 10 Upper chord material 11 Precast concrete segment of upper chord material 12 Connection metal fitting 13,23,33 Arrow 14 End surface 15 Connection part 20 Lower chord material 21 Precast concrete segment of lower chord material 22 Connection metal fitting 25 Connection part 30 Diagonal material 31 Single diagonal material 32 Connecting part 40 Upper floor slab 50 Lower floor slab

Claims (3)

  The upper chord material and the lower chord material made of precast concrete segments projecting connecting metal fittings to be connected to the diagonal material, and the diagonal material provided with the connecting end portions of the connecting metal metal at both ends are individually manufactured in advance and installed at the installation site. The truss bridge is constructed by connecting the upper and lower chord members and the diagonal member, and connecting the upper chord member and the lower chord member to the adjacent existing upper and lower chord members with PC tension members, respectively.   2. The truss bridge erection method according to claim 1, wherein the upper chord material is a precast concrete segment integrated with an upper floor slab of the truss bridge.   2. The truss bridge erection method according to claim 1, wherein the lower chord material is a precast concrete segment integrated with a lower floor slab of the truss bridge.

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