JP2000104220A - Erection of combined truss bridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the term of works by hanging steel truss beams from bridge piers, mounting the moving forms on top chords and bottom coards of the beam, applying the concrete, and hanging the beam on the top chords by a crane. SOLUTION: A steel truss beam is hung by one span from a bridge piear, the moving forms are installed on the truss top chord 3 and the truss bottom chord 4 of the beam, and the concrete is applied to the forms 10 to construct the top and bottom concrete floor boards. Then a beam is hung between the span and a next span by the crane 12, and the concrete is applied to the form 10 to construct the top and bottom concrete floor boards. Then the crane 12 is moved to hang the beam of a next span by the crane 12, and the concrete is applied to the form 10 to construct the top and bottom concrete floor boards. The same processes are repeated until the spans of the bridge are combined by the beams. Further the fixed forms are installed while removing the execution equipment by the crane 12, and the concrete is applied to construct the top concrete floor board. Whereby the term of works can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a composite truss bridge which can be overhanged and a method of erection.

[0002]

2. Description of the Related Art As a prior art relating to the present invention, Japanese Patent Application Laid-Open
The invention described in No. 10-140525 is known.

In the present invention, as one form of a composite truss bridge which can be overhanged, a slab having a plurality of concrete webs is joined to a steel truss as shown in FIG.

[0004] Thus, the girder becomes rigid, and it becomes possible to erection erection. In addition, the span length of the bridge is larger than that of a conventional composite truss girder that is rigidly connected to a pier consisting of a prestressed concrete slab that forms the bridge surface and a steel truss girder that does not include the truss upper chords joined to the lower surface. However, it is possible to prevent the steel material from being enlarged, and it is convenient to transport the material.

[0005]

However, the prior art has the following problems.

In the prior art, a truss structure is not formed only by steel materials. Therefore, it is necessary to increase the rigidity of the entire slab by increasing the rigidity of the floor slab, and the cross section of the floor slab must be increased in size and complexity. Also, since the truss structure was not formed before concrete hardening, the concrete slab was joined with a crane above the pier and joined, or the concrete was poured while the formwork was lifted with a crane above the pier. There is a need.

Therefore, in the prior art having a large weight per unit length, there is a problem that it is difficult to join a long section of slab or to cast concrete in a long section at a time, so that the construction period becomes long. .

The present invention has been made in view of such a problem, and an object of the present invention is to provide a method of erection of a composite truss bridge capable of shortening a construction period.

[0009]

SUMMARY OF THE INVENTION The present invention has the following arrangement to solve the above-mentioned problems.

[0010] The gist of the present invention is to provide a steel truss girder having a steel upper chord, a lower chord and a diagonal member, and a concrete slab forming a bridge surface constructed on the upper surface of the steel truss girder. A method of erection of a composite truss bridge comprising: a step of extending a steel truss girder by one span in the direction of erection from two erected piers on which the composite truss girder is erected; Installing a movable formwork on the upper chord material and the lower chord material, placing concrete in the movable formwork and constructing a floor slab, and in parallel with the step, on the upper chord material in a bridge axis direction. A step of projecting a steel truss girder of the next span using a mobile crane installed movably, and performing the steps and the steps until the steel truss girder is connected. It depends on how to build the bridge. The gist of the invention according to claim 2 includes a steel truss girder having steel upper chord, lower chord and diagonal, and a concrete slab forming a bridge surface constructed on the upper surface of the steel truss girder. A method of erection of a composite truss bridge, comprising: a step of extending a steel truss girder by one span in a direction of erection from two erected piers on which the composite truss girder is erected; , And installing a movable formwork on the lower chord material, a step of constructing a floor slab by casting concrete in the movable formwork, and a step of introducing a prestressing force to the floor slab after the concrete has hardened. In parallel with this step, a step of projecting a steel truss girder of the next diameter using an erecting moving crane installed movably in the bridge axis direction on the upper chord member is provided, and the steel truss girder is connected. Up to the above steps are repeated. In the construction method of a composite truss bridge. The gist of the invention according to claim 3 includes a steel truss girder having steel upper chord, lower chord and diagonal, and a concrete slab forming a bridge surface constructed on the upper surface of the steel truss girder. A method of erection of a composite truss bridge,
The composite truss girder is erected, a step of extending a steel truss for one span in the erection direction from the two erected piers, and installing a movable formwork on the upper chord and the lower chord of the overhanging steel truss girder. A step of placing concrete in the movable formwork to construct a floor slab; a step of introducing a prestressing force to the floor slab after the concrete is hardened; A step of projecting a steel truss girder of the next span using a erection moving crane installed movably in the bridge axis direction on the material, and repeatedly performing the above-described steps from the above until the steel truss girder is connected The present invention resides in a method for erection of a composite truss bridge. The gist of the invention according to claim 4 lies in the method of erection of a composite truss bridge according to claims 1 to 3, wherein the overhang of the steel truss girder is performed symmetrically across the pier. The gist of the invention described in claim 5 resides in a composite truss bridge which is constructed by the method for constructing a composite truss bridge according to any one of claims 1 to 4.

In the claims, the numerals... Do not indicate the same steps in the claims.

[0012]

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

As shown in FIGS. 1 and 2, the composite truss bridge according to the present embodiment has piers P, P erected on the ground G.
And a concrete slab 1 and a lower concrete slab 2 forming a bridge surface constructed on the steel truss girder C.

The steel truss girder C is roughly composed of a truss upper chord 3, a truss lower chord 4, and a truss slant 5.

In the upper concrete slab 1 and the lower concrete slab 2, concrete is cast into a movable form 10 which moves on the truss upper chord 3 and the truss lower chord 4, and the truss upper chord 3 and the truss lower chord 4 are laid. Each is rigidly connected, and both have a prestress. In the figure, reference numeral 7 denotes a prestress cable. Pavement 6 is constructed on the upper surface.

The construction crane 12 travels on a crane rail 16 laid on the truss upper chord 3 as shown in FIGS. The crane rail 16 is shown in FIG.
As shown in FIG. 5 and FIG. 16, it is composed of a rail 16a and a fixing portion 16b extending downward from the lower surface of the rail 16a. In order to fix the rail 16 to the truss upper chord 3, the fixing portion 16 a may be inserted into a steel pipe 1 a erected on the truss upper chord 3 as shown in FIGS. 17 and 18.
Both figures show a state in which the rail 16 has been withdrawn. That is, in the present embodiment, as described later,
Before laying the concrete, lay rails 16,
The concrete placing and the construction of the steel truss girder C of the next diameter are performed in parallel. Then, the rail 16a is withdrawn after the collection mobile crane 12 is collected.

FIG. 2i) shows a cross section with the lower concrete slab 2, and FIG. 2ii) shows a cross section without the lower concrete slab 2.

Next, a method of erection of the composite truss bridge B shown in FIG. 3 will be described with reference to FIGS. The composite truss bridge B shown in FIG. 3 is different from the composite truss bridge B shown in FIGS. 1 and 2 in that the steel lower chord 4 is on the arch, but the other components are the same.

First, the truss upper chord 3, the truss lower chord 4 and the like are carried into the site by the truck 9, and as shown in FIG. Installed by car 8.

Then, as shown in FIG. 5, a steel truss girder C is extended by one span in the bridge axis direction on both sides of the erection of the tower column rigid connection portion of the pier P.

Next, as shown in FIG. 6, the rail 16 for the crane is laid on the upper chord member 3 of the truss.

Next, as shown in FIG. 7, a moving crane 12 for erection is installed on the upper concrete slab 1.

Next, the movable formwork 10 is installed on the truss upper chord member 3 and the truss lower chord member 4 of the overhanging steel truss girder C, and concrete is poured into the movable formwork 10 to make the upper concrete floor slab 1 and the lower concrete slab 1 lower. A concrete slab 2 is constructed and the truss upper chord 3 and the truss lower chord 4 are separately synthesized.
The same applies to the following figures. In the figure, reference numeral 11 denotes a scaffold. The concrete placing device and the moving frame 10 are different from each other in the upper and lower concrete floor slabs 1 and 2. Therefore, the upper concrete slab 1 may be constructed first, or the lower concrete slab 2 may be constructed first. Further, the upper and lower concrete slabs 1 and 2 can be constructed in parallel. After the concrete has hardened, a prestressing force is introduced into the upper and lower concrete floor slabs 1 and 2.

As shown in FIG. 8, a steel truss girder C is extended to the next diameter in parallel with the concrete placement.

Then, as shown in FIG. 9, the next second span steel truss girder C is
The movable formwork 10 is installed on the truss upper chord material 3 and the truss lower chord material 4 and concrete is poured into the movable formwork 10 to construct the upper and lower concrete floor slabs 1 and 2.

Next, after the concrete of the second span has hardened, a prestressing force is introduced into the upper and lower concrete slabs 1 and 2, and as shown in FIG. The steel truss girder C of the next third span is overhanged by using the moving crane 12 for erection, and the upper and lower concrete slabs 1 and 2 are constructed by the movable formwork 10.

From the top of one or a plurality of pier columns, simultaneously, the upper and lower concrete slabs 1 and 2 of the composite truss bridge B are simultaneously driven into a portion where the strength of the girder cannot be maintained unless combined. Perform multiple times.

As shown in FIG. 11, the steel truss girder C is repeated until the span of the bridge is connected, and the span is connected.

Thereafter, while the moving crane 12 returns to the pier P from the center of the span, as shown in FIG.
3 and formwork 10 'for the upper concrete slab 1
(Not the movable formwork 10). Finally, concrete is poured into the fixed formwork 10 'at a stretch, and the upper concrete floor slab 1 is constructed. In addition, the usual fixed formwork 10 '
Instead, the movable mold 10 can be used.

Since the composite truss bridge and the method of erection thereof according to the embodiment are configured as described above, the following effects can be obtained.

Since the composite truss girder B to which the present invention is applied is provided with the truss upper chord member 3, the steel truss C itself has a large rigidity. Therefore, the floor slabs 1,
Since 2 can have a simple flat plate structure, the workability is good and the construction period can be shortened.

After the rigid overhang truss C is completed, the truss C itself has a large supporting force, so that the concrete can be cast only by installing the movable formwork 10 on the truss upper chord 3. .

Since the steel truss C has high rigidity even before being combined with the upper and lower floor slabs 1 and 2, it is possible to install the erection equipment on the steel truss C.

Therefore, the step of placing the upper and lower floor slabs 1 and 2 and the step of erection of the steel truss B can be performed simultaneously. That is, it is possible to reduce the construction period by half.

Further, since the concrete placing section can be made as long as one span of the truss at a time, the construction period can be further shortened.

Therefore, the installation of the truss upper chord member 3 employed in the present embodiment makes it possible to greatly shorten the construction period as compared with the conventional overhang erection.

Further, the steel truss girders C can be extended to the right and left sides.

The present invention is not limited to the composite truss bridge according to the above-described embodiment, but can be applied to a bridge suitable for applying the present invention.

Further, the truss girder C of the next diameter was overhanged in parallel with the concrete placement, but in parallel with the introduction of the prestress or in parallel with the concrete placement and the introduction of the prestress. Overhang of the steel truss girder C can also be performed.

The rail 16a can be used for a fence or the like.

The girders were expanded symmetrically.
It can also be applied to cantilever overhangs.

Further, the number, position, shape, etc. of the above-mentioned constituent members are not limited to the above-mentioned embodiment, but can be set to a suitable number, position, shape, etc. for carrying out the present invention.

In the drawings, the same components are denoted by the same reference numerals.

[0044]

Since the present invention is configured as described above, the following effects can be obtained. Casting concrete for constructing floor slabs, or introducing the casting and prestressing, and extending the steel truss to the next span are performed in parallel. The construction period can be shortened.

[Brief description of the drawings]

FIG. 1 is a side view of a composite truss bridge according to an embodiment of the present invention.

2] i is an end view taken along the line MM in FIG. 1, and ii) is a line n- in FIG.
It is an n end view.

FIG. 3 is a perspective view of a composite truss bridge according to another embodiment of the present invention.

FIG. 4 is a process diagram (side view) of the method of erection of the composite truss bridge shown in FIG. 3;

FIG. 5 is a process diagram (side view) of a method of erection of the composite truss bridge shown in FIG. 3;

6 is a process diagram (side view) of a method of erection of the composite truss bridge shown in FIG. 3;

FIG. 7 is a process diagram (side view) of the method of erection of the composite truss bridge shown in FIG. 3;

FIG. 8 is a process diagram (side view) of the method of erection of the composite truss bridge shown in FIG. 3;

9 is a process diagram (side view) of the method of erection of the composite truss bridge shown in FIG.

10 is a process diagram (side view) of the method of erection of the composite truss bridge shown in FIG. 3;

11 is a process diagram (side view) of the method of erection of the composite truss bridge shown in FIG. 3;

12 is a process diagram (side view) of the method of erection of the composite truss bridge shown in FIG. 3;

FIG. 13 is a front view (excluding a pier portion) of the construction mobile crane shown in FIG. 7;

14 is a side view of the mobile crane for erection shown in FIG.

FIG. 15 is a plan view of the installed upper slab shown in FIG. 7;

FIG. 16 is a front view (excluding a pier portion) of the process diagram shown in FIG. 7;

FIG. 17 is a front view (excluding a pier portion) of the process drawing shown in FIG. 7;

FIG. 18 is a front view (excluding a pier portion) of the process drawing shown in FIG. 7;

FIG. 19 is a cross-sectional view of a conventional bridge structure of a composite truss bridge which can be overhanged.

[Explanation of symbols]

 B Composite truss bridge C Steel truss girder G Ground P Pier 1 Upper deck 2 Lower deck 3 Truss upper chord 4 Truss lower chord 5 Truss diagonal 6 Pavement 7 Prestressed cable 8 Crane truck 9 Truck 10 Moving form 11 Scaffolding 12 Erecting Mobile crane 13 lining equipment 14 concrete filled steel pipe 16 rail for crane 16a rail 16b fixing part

Claims (5)

[Claims] 1. Construction of a composite truss bridge including a steel truss girder having steel upper chord, lower chord and diagonal, and a concrete slab forming a bridge surface constructed on the upper surface of the steel truss girder. A method, comprising: extending a steel truss girder by one span in the direction of erection from two erected piers, on which the composite truss girder is erected; A step of installing a movable formwork, casting concrete on the movable formwork to construct a floor slab, and, in parallel with the step, moving the erection on the upper chord member so as to be movable in a bridge axis direction. A method of erection of a steel truss girder of the next span using a crane, wherein the steps and the steps are performed until the steel truss girder is connected. 2. Construction of a composite truss bridge comprising a steel truss girder having steel upper chord, lower chord and diagonal, and a concrete slab forming a bridge surface constructed on the upper surface of the steel truss girder. A method, comprising: extending a steel truss girder by one span in the direction of erection from two erected piers, on which the composite truss girder is erected; Installing a movable formwork, placing concrete on the movable formwork to construct a floor slab, and introducing a prestressing force to the floor slab after the concrete has hardened; A step of projecting a steel truss girder of the next span using a erection moving crane installed movably in the bridge axis direction on the upper chord material, wherein the steel truss girder is connected until the steel truss girder is connected. Composite truss characterized by repeating the process How to build a bridge. 3. A composite truss bridge erection comprising a steel truss girder having steel upper chords, lower chords and diagonal members, and a concrete slab forming a bridge surface formed on the upper surface of the steel truss girder. A method of extending a steel truss for one span in the direction of erection from two erected piers on which the composite truss girder is erected, and moving the overhanging steel truss girder to an upper chord and a lower chord. Installing a formwork, casting concrete on the movable formwork to construct a floor slab, after hardening the concrete, introducing a prestressing force to the floor slab; And a step of projecting a steel truss girder of the next span using a erection moving crane installed movably in the bridge axis direction on the upper chord material, wherein the steel truss girder is connected until the steel truss girder is connected. The method is characterized by repeating the above steps. How to build a joint truss bridge. 4. The method for erection of a composite truss bridge according to claim 1, wherein the overhang of the steel truss girder is performed symmetrically across the pier. 5. A composite truss bridge constructed by the method for constructing a composite truss bridge according to claim 1.