JPH0959932A - Construction method of column head of overhanging erection girder bridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of high elevation work and contrive a common use or conversion of materials and members when constructing a column head of an overhanging erection girder bridge. SOLUTION: A section steel bent structure 10 is set up on the head 1 of a bridge pier where a vertical beam and a horizontal beam 12 are erected on the bent structure 10. From the respective beams, there hang a crane and a hoist material. Support materials, scaffoldings and equipment materials assembled on the ground are hoisted and shifted to and provided on the hoist material 15. The section steel of the bent structure 10 is employed for a concrete reinforcing material as it is and converted as a horizontal beam of an erection work car.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a stilt head of an overhanging girder bridge, which serves as a base point for overhanging a prestressed concrete (PC) bridge.

[0002]

2. Description of the Related Art A bridge overhanging method for constructing a bridge by constructing a bridge by dividing it from the bridge pier into 3 to 5 m in the axial direction of the bridge and alternately projecting to the left and right is It is suitable for erection of bridges and is widely adopted because it is not restricted by the space conditions under girders. This overhang erection method is
First, a stilt head, which is a base point (overhanging start point), is built on the head of the pier, and then two erection work vehicles are assembled and mounted on the stanchion head via a rail for movement so as to be able to move forward and backward. , Suspend and support the formwork and scaffolding from this erection work vehicle, assemble the rebar etc. in the formwork, place concrete, and balance the bridge block left and right from the base point, and build the bridge body in Yajirobei style. Build a cantilever overhang.

FIG. 8 shows an example of an overhanging erection method in which a bridge pier head 1 and a pier head 2 are constructed at the upper end of a pier 3, and blocks 60 are sequentially extended from the pier head 2 to the left and right. The erection work vehicle 50 moves forward over the bridge body that has been successively overlaid,
The scaffolding and formwork of the next block are overhanged and held forward, and concrete is poured. And each pier 3, 3, ...
The pier is constructed with the base point as the base point, and the bridges are connected in the middle of the piers 3 to complete the bridge erection.

In the case of the above-mentioned erection erection method, the stilt head 2 is usually constructed by assembling scaffolds from the ground along the bridge piers, providing scaffolds for constructing the stilt heads, and attaching support brackets for stilt head construction to the piers. It was done. The pier may sometimes reach a height of 50 m or more above the ground, and the pier head 1 is added at a high position, and the support bracket for the pier head 2 is attached.
It requires work such as installation of work scaffolds, assembling of the form of the stilt head 2, pouring of stilt head concrete, and careful work from the viewpoint of safety.

Conventionally, when constructing an overhanging girder bridge, it has been common for different technical staff members to carry out the construction of the bridge body (superstructure) and bridge pier (substructure), respectively. A part of the upper part (the head of the pier) of 2-3 m is being shared by the technical staff in charge of superstructure. This is because it is necessary to bury bearing anchor bolts for supporting the bridge body at the head of the bridge pier, anchor bars for responding to the unbalance moment during overhanging, and temporary materials such as temporary steel rods. Because of this, prior to the construction of the stilts for the superstructure, the scaffolds and the scaffolds used during the construction of the substructure were re-attached to the scaffolds to support the construction of the pier head and stilts (brackets). ) Was installed at high places, and work such as assembling the formwork was required. Further, after the completion of the pillar head, assembling the erection work vehicle for erection erection, suspending the erection erection scaffolding,
There is room for improvement in terms of work efficiency and safety, since it is necessary to assemble the formwork with a narrow stigma.

[0006]

SUMMARY OF THE INVENTION According to the present invention, it is possible to assemble things that can be constructed by ground work on the ground as much as possible, reduce work at high places, and share or divert materials and members. It is an object of the present invention to provide a method of constructing a pillar head of an overhanging girder bridge that can omit unnecessary lifting and lowering.

[0007]

DISCLOSURE OF THE INVENTION The present invention relates to a pier head,
A shaped steel vent structure is installed, and a vertical beam parallel to the bridge axis and a horizontal beam orthogonal to the vertical beam are installed on this bent structure, and a lifting machine is hung from the horizontal beam and / or the vertical beam, and suspended from each beam. Suspend the materials and assemble the support materials, work scaffolds and equipment assembled on the ground with a hoisting machine, and replace them with the suspension materials to support them.After that, support installation on the scaffolding, formwork assembly, pier head And a method for constructing a pillar head of an overhanging girder bridge, characterized by placing concrete on the pillar head to construct the pillar head.

At this time, it is preferable that a part of the shaped steel vent structure is a shaped steel that also serves as an anchor bar steel frame of a column head that resists an unbalance moment during overhanging. Also,
After constructing the stilts, the horizontal beam of the vent structure is made into a shaped steel that can be diverted to the horizontal beam of an erection work vehicle used for overhanging and erection, so that the minimum required lifting of equipment can be achieved.

[0009]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory view showing the concept of the present invention, and shows a state in which a pillar head 2 is constructed using a vent structure 10 whose lower end is buried in the concrete of the bridge pier head 1. The left half of FIG. 1 illustrates a case in which the bridge pier head 1 and the column head 2 are integrated into a rigid frame structure. In this case, as will be described later, the vent structure 10 uses the pier head portion 1 as a structural material that connects the pier head portion 2 with the pier head portion 2. FIG.
The right half of the figure shows the case of a continuous girder type in which the pier head portion 1 and the pier head portion 2 are separated. In the case of the continuous girder type, the bridge pier head 1 and the pillar head 2 are fixed with the temporary steel rods 23 through the temporary recess 21 when the pillar head 2 is constructed, and temporarily after the bridge body is completed. Remove the sinker 21 and replace it with the sinker 22. At this time, the vent structure 10 is also cut. The cross beam 12 provided on the vent structure 10 suspends the scaffolding and the suspending material 15 for suspending the formwork.

2 to 6 show the construction process of the present invention. Vent structure 1 using H-section steel on the ground near the pier 3
0 is assembled and installed on the top of the pier with a crane. Next, FIG.
As shown in FIG.
A cross beam 12 is erected, and a lifting machine 17 for lifting work scaffolds and materials, and a suspending member 15 for suspending and supporting scaffolds and supports are attached to the vertical beams 11 and cross beams 12.

Next, the work gantry 31 which also serves as a work scaffold is assembled on the ground, hoisted by the hoist 17 to the bridge pier head building position, and fixed to the hanging material 15 (FIG. 3). Next, using this work gantry 31, a frame and reinforcing bars (not shown) of the pier head 1 are assembled, and concrete is poured to construct the pier head 1. When the concrete of the pier head 1 is hardened, the scaffolding position is adjusted by the lifting machine 17 (chain block), the pillar head support 35 and the form support 32 are adjusted, and the form, rebar and PC steel not shown Then, the concrete of the pillar head 2 is placed (Fig. 4). At this time, part of the H-shaped steel of the vent structure 10 is integrally embedded in the concrete of the pier head 1 and the pillar head 2, respectively. When the structure of the bridge is a rigid frame structure, as shown in the left half of Figure 1, the pier head 1
When the structural type of the bridge is a continuous girder, the bottom formwork of the pillar head 1 is applied as shown in the right half of FIG. 1, and the main shoe 22 and the temporary timber are provided on the upper surface of the pier. 21 is installed and the bridge pier head 1 and the pier head 2 are cut off to construct.

After the concrete of the pillar head 2 hardens, a rail 52 for moving the erection work vehicle is laid, and as shown in FIG. 5, the rail is moved to the front position in the overhanging direction and the rear end of the rail is temporarily fixed with an anchor. To install the erection work vehicle main frame 50. The main frame 50 is lifted by a truck lane (not shown) or a cable crane, incorporated from the front of the vent structure (bridge center direction span center side), placed on the moving rail via wheels, and extended with the moving rail. It moves backward to the first block construction position (position in FIG. 4), the horizontal beam 12 of the vent structure 10 is replaced with the erection work vehicle 50, and the support 35, the form support 32, and the work gantry 31 are erected from the vent structure 10. The work vehicle 50 bears the burden. Similarly, the erection work vehicle for overhanging on the opposite side is incorporated, but since there is no space for incorporating two erection work vehicles at the same time, the first block 60 is overhanged and constructed, and the erection work vehicle is moved forward to extend on the opposite side. In the same manner, a work vehicle for erection and erection is incorporated, and a transverse beam is similarly replaced from the vent structure, and then erection and erection are alternately carried out while balancing left and right from the pillar head 2 by a known method to successively construct the bridge block 60.

FIG. 6 is a plan view of FIG. 5, and the left half is A of FIG.
The arrow view, the right half shows the arrow B view of FIG. The main frame 50 is hung from the projecting front surface, mounted and mounted on the rail 52, and retracted to the position shown in FIG. 7 is a view taken in the direction of arrows C and D in FIG. 4, the left half is a view taken in the direction of arrow C in FIG. 4, and the right half is a view taken in the direction of arrow D in FIG. After the bridge is completed, cut the vent structure above the bridge surface. In the case of continuous girders, after the overhanging is completed and the bridges between the piers are connected, the vent structure H-shaped steel between the column head 2 and the upper surface of the piers is cut and removed, and the weight of the bridge is added to the main timber 22. Support and remove the temporary shoe 21 (right of Fig. 1).

[0014]

According to the method of the present invention, the vent structure equipped with the hoisting machine is first erected, and the work gantry assembled on the ground is hoisted to minimize the work in high places and to ensure the safety. At the same time, the beam material, supporting material, formwork, etc. are diverted to the bridge pier head, the bridge pillar head, and the overhanging bridge body one after another, and the unbalance moment when a part of the bent structural steel material is extended. By using it for the anchor bar corresponding to the above, it became possible to obtain a great effect on saving by improving the effective use of materials and equipment, improving safety, and improving work efficiency.

The effects of the present invention will be described in detail below. (1) The scaffold for bridge pier head construction and the bracket assembly scaffold are
Conventionally, scaffolds were assembled from the ground along the bridge piers, but assembling from the ground is no longer required, and the brackets for the pillar head construction are also unnecessary, work efficiency is significantly improved, and work safety management is improved. It will be extremely easy. (2) Work floors, formwork materials, etc. used to construct the pillar head,
It can be used as it is for overhanging construction work of erection work vehicles. If the main frame for the erection work vehicle is placed and the cross beam is replaced, the overhanging erection work can be started immediately. The diversion of equipment is increased, and the number of trucks and unloading of equipment can be reduced. (3) Anchor and PC for fixing the pillar support bracket
Eliminates the need for steel rods. In the structural type that receives the stilts at the temporary sink, temporary steel rods and shaped steel with a bent structure can be used for the H steel for the stopper, and the overall work becomes rational. (4) Since the lifting and lowering of the work floor is performed by a lifting machine, the vertical adjustment of the scaffold can be easily performed. (5) It is possible to shorten the construction period of the bridge pier head and the pillar head construction, to start the construction of the overhanging and erection work early, and to shorten the total number of work days.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a method of constructing a stigma of an example.

FIG. 2 is an explanatory diagram of a method of constructing a stigma of an example.

FIG. 3 is an explanatory diagram of a method of constructing a stigma of an example.

FIG. 4 is an explanatory diagram of a method of constructing a stigma of an example.

FIG. 5 is a side view showing the installation of the erection work vehicle.

FIG. 6 is a view as seen from arrows A and B in FIG.

FIG. 7 is a view taken in the directions of arrows C and D in FIG.

FIG. 8 is an overall explanatory diagram of an example.

[Explanation of symbols]

1 Bridge pier head 2 Pillar head 3 Bridge pier 10 Vent structure 11 Vertical beam 12 Horizontal beam 13 Column 15 Hanging material 17 Lifting machine (electric chain block) 18 Chain 21 Temporary grove 22 Main bar 23 Temporary steel bar 31 Work gantry 32 Form support material 34 chain 35 support work 50 erection work vehicle (main frame) 51 main frame front part 52 rail 60 block

Claims (3)

[Claims] 1. A shaped steel vent structure is installed on the bridge pier head,
A vertical beam parallel to the bridge axis and a horizontal beam orthogonal to the vertical beam are erected on the vent structure, a lifting machine is hung from the horizontal beam and / or the vertical beam, and a suspension member is hung from each beam, The supporting materials, work scaffolds, and equipment assembled on the ground are hoisted by hoisting machines, and the supporting materials are transferred to and supported by the lifting materials. A method for constructing a column head of an overhanging girder bridge characterized by constructing a column head by placing it. 2. Construction of a column head of an overhanging girder bridge according to claim 1, wherein the shaped steel vent structure is a shaped steel vent structure made of a shaped steel that also serves as an anchor bar steel frame of the stilt. Method. 3. The method for constructing a stilt head of an overhanging girder bridge according to claim 1 or 2, wherein after constructing the stilt head, the cross beam is diverted to a cross beam of an erection work vehicle.