JP3110985B2 - Construction method of column capital of overhang 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 for constructing a column head of an overhanging girder bridge, which is a base point for overhanging a prestressed concrete (PC) bridge.

[0002]

2. Description of the Related Art An overhanging construction method of a bridge, which is constructed by using an installation work vehicle and dividing the bridge body from the top of a pier at intervals of 3 to 5 m in the bridge axis direction and alternately extending the bridge body from side to side, is known. It is suitable for erection of bridges and is not restricted by under-girder space conditions. This overhang construction method,
First, a column capital that serves as a base point (overhang start point) is constructed at the head of the pier, and then two erection work vehicles are assembled and mounted on the column capital via a moving rail so as to be able to move forward and backward. From this construction work vehicle, formwork and scaffolds are suspended and supported, steel bars are assembled in the formwork, concrete is cast, and the bridge body is laid in a yajirobei style while balancing the bridge body block from left to right from the base point. Build a cantilever overhang.

FIG. 8 shows an example of a method of erection and erection, in which a pier head 1 and a column capital 2 are constructed at the upper end of a pier 3, and blocks 60 are sequentially constructed from the column capital 2 to the left and right. The erection work vehicle 50 moves forward on the bridge body that has been sequentially erected,
Overhang and hold the scaffolding and formwork of the next block and pour concrete. And each pier 3, 3, ...
And the bridge body is connected in the middle of the piers 3, 3 to complete the bridge body erection.

In the case of the above-mentioned overhanging method, the capital 2 is usually constructed by assembling a scaffold from the ground along the pier, providing a scaffold for the construction of the capital, and attaching a support bracket for the construction of the capital to the pier. It was done. Sometimes the pier can reach more than 50m above ground level, so the pier head 1 can be overstretched at high elevations,
Work such as installation of a work scaffold, assembling the formwork of the column capital 2 and placing concrete of the capital of the capital is required, and also requires careful work from the viewpoint of safety.

Conventionally, when constructing an overhanging girder bridge, the construction of the bridge body (superstructure) and the pier (substructure) are generally performed by different technical staffs. A part of the upper part (bridge pier) 2 to 3 m is assigned to the supervising engineer. This means that it is necessary to embed temporary materials such as anchor bolts for supporting the bridge body, anchor bars to cope with unbalanced moments during overhanging, temporary steel rods, etc. Because of this, prior to the construction of the capital of the superstructure, the scaffolds used during the substructure construction and the pier from which the support was removed were re-hung, and the support (bracket) for the construction of the pier head and the capital was constructed. ) Was installed at a high place and required work such as assembling the formwork. Furthermore, after the completion of the capital, assembling the erection work vehicle for the overhanging erection, suspending the overhanging scaffolding,
It is necessary to assemble the formwork with a narrow capital, and there is still room for improvement from the viewpoint of work efficiency and safety.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is to assemble objects that can be constructed in ground work on the ground as much as possible, to reduce work in high places, and to share or divert materials and members. In addition, an object of the present invention is to provide a method of constructing a column head of an overhanging girder bridge in which unnecessary lifting and hanging down can be omitted.

[0007]

Means for Solving the Problems The present invention, Ann stigma portion
Bridge pier with a shaped steel vent structure made of shaped steel that also serves as a carver steel frame
Installed on the head, a vertical beam parallel to the bridge axis and a horizontal beam orthogonal to the vertical beam are erected on this vent structure, a lifting machine is suspended from the horizontal beam and / or the vertical beam, and a hanging material is suspended from each beam. Suspended suspension materials, work scaffolds and equipment assembled on the ground are lifted by a hoist, and transferred to and supported by the lifting materials. After that, the supports are attached and formwork is assembled on the scaffolds, and the pier head and capital After placing the concrete in the part and constructing the capital,
This is a method of constructing a column head of an overhanging girder bridge, which is diverted to a cross beam of an erection work vehicle .

[0008] before Kikatachiko vent structure shall be the shape steel, which also serves as the anchor bar steel frame of the stigma part to resist the unbalanced moment at the time of the overhanging erection. In addition, after building the capital, by using the cross-section steel beam of the vent structure as a cross-section steel beam that can be diverted to the cross beam of the erection work vehicle used for the overhanging erection, it is possible to lift the minimum necessary equipment and materials. .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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 column cap 2 is constructed by using a vent structure 10 whose lower end is buried in concrete of a pier head 1. The left half of FIG. 1 illustrates a case where the bridge pier head 1 and the column head 2 have an integral rigid frame structure. In this case, as will be described later, the vent structure 10 uses the pier head 1 as a structural material for connecting the pier head 2 with the pier head 2. FIG.
The right half shows the case of a continuous girder type in which the pier head 1 and the column head 2 are separated. In the case of the continuous girder type, when constructing the column cap 2, the pier head 1 and the column cap 2 are fixed with temporary steel rods 23 through the temporary shoes 21, and after all the bridge bodies are completed, Remove the shoe 21 and replace it with the actual shoe 22. At this time, the vent structure 10 is also cut. The cross beam 12 provided in the vent structure 10 suspends a scaffold, a hanging material 15 for formwork suspension, and the like.

FIGS. 2 to 6 show the construction process of the present invention. Vent structure 1 using H-section steel on the ground near pier 3
Assemble No. 0 and install it on the pier top with a crane. Next, FIG.
As shown in FIG.
A cross beam 12 is erected, and a hoisting machine 17 for lifting work scaffolds and materials and a suspending member 15 for suspending and supporting the scaffolds and supports are attached to the vertical beams 11 and the cross beams 12.

Next, the work gantry 31, which also serves as a work scaffold, is assembled on the ground, lifted to the bridge pier head construction position by the hoisting machine 17, and fixed to the hanging members 15 (FIG. 3). Next, using the work gantry 31, a formwork and a reinforcing bar (not shown) of the pier head 1 are assembled, and concrete is cast to construct the pier head 1. When the concrete of the pier head 1 is hardened, the scaffold position is adjusted by the hoisting machine 17 (chain block), and the column cap support 35 and the form support material 32 are adjusted to form a form, a reinforcing bar, and a PC steel, which are not shown. And concrete of the column capital 2 is poured (FIG. 4). At this time, a part of the H-shaped steel of the vent structure 10 is embedded in the concrete of the pier head 1 and the column head 2 respectively. When the structure type of the bridge body is a ramen structure, as shown in the left half of FIG.
When the bridge type is a continuous girder, the bottom formwork of the capital part 1 is applied as shown in the right half of FIG. 1 and the main shoe 22 and the temporary shoe are provided on the pier upper surface. 21 is installed and the bridge pier head 1 and the column cap 2 are cut off and constructed.

After the concrete of the column capital 2 is hardened, 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 extending direction, and the rear end of the rail is temporarily fixed with an anchor. The installation work vehicle main frame 50 is prepared for installation. The main frame 50 is lifted by a truck lane or a cable crane (not shown), assembled from the front of the vent structure (the center of the span in the direction in which the bridge is extended), mounted on a moving rail via wheels, and extended with the moving rail. It is retracted to the first block construction position (the position shown in FIG. 4), the cross beam 12 of the vent structure 10 is replaced with an erection work vehicle 50, and the support 35, the form support material 32, and the work gantry 31 are supported from the vent structure 10. The work vehicle 50 is charged. Similarly, an installation work vehicle for the opposite side overhang is installed. However, since there is no space for installing two installation work vehicles at the same time, the first block 60 is extended and constructed, and the installation work vehicle is advanced, and the opposite side overhang is performed. An outrigger work vehicle is installed, the cross beam is similarly replaced from the vent structure, and then the bridge block 60 is successively constructed by alternately overhanging the bridge from the column capital 2 while keeping the balance from side to side in a known manner.

FIG. 6 is a plan view of FIG. 5, and the left half of FIG.
The view on the arrow and the right half show the view on the arrow B in FIG. The main frame 50 is suspended from the front of the overhang, 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 a continuous girder, after the overhanging is completed and the bridge between the piers is connected, the bent H-shaped steel between the column cap 2 and the upper surface of the pier is cut off and the bridge body weight is added to the main shoe 22. The temporary shoe 21 is removed and supported (Fig. 1, right).

[0014]

According to the method of the present invention, a vent structure equipped with a lifting machine is first erected, and a work gantry assembled on the ground is lifted to minimize work at a high place, thereby improving safety. At the same time, beams, support materials, formwork, etc. are diverted one after another to the pier head, bridge column head, and overhang bridge body, and the unbalance moment when part of the vent structural steel is overhanged It can also be used for the anchor bar corresponding to, and it is possible to obtain tremendous effects such as saving by effective use of equipment and materials, improvement of safety and improvement of work efficiency.

The effects of the present invention will be described below in detail. (1) The pier head construction scaffold and the bracket assembly scaffold are
In the past, scaffolding was assembled from the ground along the piers, but assembling from the ground is no longer necessary, brackets for capital construction are not required, work efficiency is significantly improved, and work safety management is improved. It becomes very easy. (2) Work floors, formwork materials, etc. used for construction of capitals,
It can be diverted as it is to erection work of erection work vehicle. If the main frame for the construction work vehicle is arranged and the cross beam is replaced, the construction of the overhang construction work can be started as it is. Diversion of the equipment is increased, and the number of trucks and unloading of the equipment can be reduced. (3) Anchor and PC for fixing capital support bracket
Steel bars are not required. In the structure type in which the temporary shoe is used to receive the capital, a bent steel bar can be used for the temporary steel bar and the H steel for the stopper, so that the entire work is streamlined. (4) Since the lifting and lowering of the work floor is performed by the hoist, the vertical movement of the scaffold can be easily adjusted. (5) The construction period of the pier head and the column capital can be shortened, the overhanging work can be started earlier, and the total number of working days can be shortened.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a method for constructing a capital of an embodiment.

FIG. 2 is an explanatory view of a method for constructing a capital of an embodiment.

FIG. 3 is an explanatory view of a method for constructing a capital of an embodiment.

FIG. 4 is an explanatory view of a method for constructing a column capital according to an embodiment.

FIG. 5 is a side view of an installation work vehicle.

FIG. 6 is a view as seen from arrows A and B in FIG. 5;

FIG. 7 is a diagram viewed from arrows C and D in FIG. 4;

FIG. 8 is an overall explanatory diagram of the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Bridge pier head 2 Column head 3 Bridge pier 10 Vent structure 11 Vertical beam 12 Cross beam 13 Column 15 Suspension material 17 Lifting machine (Electric chain block) 18 Chain 21 Temporary shoe 22 Hontsutsu 23 Temporary steel rod 31 Work gantry 32 Form support 34 Chain 35 Shoring 50 Construction Work Vehicle (Main Frame) 51 Front of Main Frame 52 Rail 60 Block

Claims (1)

(57) [Claims] (1) A section steel which also serves as an anchor bar for a column capital
Installation structural steel vent structure a pier head consisting of, in the vent structure bridged the cross beam orthogonal to the parallel longitudinal beams and said longitudinal beams in bridge axis, suspended the crane from the lateral beam and / or said longitudinal beams Then, suspend the hanging material from each beam, lift the supporting material, work scaffolding and equipment assembled on the ground with a lifting machine, transfer it to the hanging material and support it, and then attach the supporting work on the scaffold, formwork Assemble and cast concrete for pier head and column head
A method of constructing a column head of an overhanging girder bridge , wherein the cross beam is converted to a cross beam of an erection work vehicle after the column capital is constructed.