JPH08134848A - Execution method of steel pipe-concrete composite structure pier - Google Patents

Abstract

PURPOSE: To improve the efficiency of the execution of works by a method wherein a hollow steel pipe disposed in upright on a foundation is hung up, a sliding form device is arranged as a bearing base, concrete is placed on the inside of sliding forms and the periphery of the steel pipe is covered with concrete. CONSTITUTION: A hollow steel pipe 2 is installed in upright on a foundation while concrete 21 is placed on the inside of the lower section of the steel pipe 2, and concrete is placed around the steel pipe 2, thus forming a lower body 3a. The segments of the steel pipe 2 are built by a tower crane 7 installed onto concrete 21 and joined. When the steel pipes 2 are piled up up to specified height, a bracket 9 is fixed at the upper end section of the steel pipes 2, and sliding form devices 8 are suspended through wires 41. Reinforcements 5 are arranged around the steel pipes 2, and concrete is placed among forms 11 and the steel pipes 2 while lifting the sliding form devices 8. The driving of concrete, the arrangement of the reinforcements, the disposal of the forms 11 and the placing of concrete are repeated successively, thus forming a body 3.

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 steel pipe / concrete composite structure pier applied to, for example, a high pier.

[0002]

2. Description of the Related Art Conventionally, in order to construct a pier, a method of constructing a reinforcing bar by combining horizontal bars with main bars arranged on a foundation, arranging a formwork on the outer periphery of the reinforcing bar, and placing concrete Has been taken.

[0003]

However, although this type of construction method is suitable for piers having a relatively low height, when applied to construction of high piers, a large number of A large number of main bars are arranged because the main bars, lateral rebars, corner haunch bars, or assembly rebars are congested, and the load becomes large when arranging work, especially when constructing high piers, At that time, the work of assembling the horizontal rebars becomes more difficult, and the man-hours for assembling and dismantling formwork materials and separators, assembling and dismantling work scaffolds, etc. become enormous, and a large number of skilled workers are required. Since it is necessary, it is extremely disadvantageous in terms of short-term rapid construction, and the construction cost is extremely high. Although an embedded mold such as a precast mold may be used in order to omit the work of dismantling the mold, the trouble of assembling the mold and treating the joint is not eliminated.

The present invention has been made in view of the above circumstances, and has as its object to provide a method of constructing a steel pipe / concrete composite structure pier capable of rapidly constructing a pier having sufficient bending strength and shear strength. I do.

[0005]

In order to achieve the above object, the method for constructing a steel pipe / concrete composite structure pier according to the present invention is such that a hollow steel pipe is erected on a foundation, and then said A sliding formwork device is arranged as a hoisting support of a hollow steel pipe, and then concrete is placed inside the sliding formwork provided in the sliding formwork device to coat concrete around the hollow steel pipe. .

According to the method for constructing a steel pipe / concrete composite structure pier of the present invention, prior to the concrete placing step of claim 1, the hollow steel pipe is surrounded by an outer periphery thereof along the surface side of the structural cross section. The PC strand is wound.

The method for constructing a steel pipe / concrete composite structure pier according to the present invention comprises installing a tower crane in the hollow steel pipe of claim 1.

Further, in the method for constructing a steel pipe / concrete composite structure pier according to the present invention, a predetermined work scaffold is attached to the tower crane so as to be able to move up and down.

[0009]

In the method for constructing a steel pipe / concrete composite structure pier according to the present invention, first, the hollow steel pipe is erected in advance using a crane, a predetermined reinforcing work is performed, and then the hollow steel pipe is used as a lifting support. Since the sliding form device is arranged and then concrete is continuously poured inside the sliding form while the sliding form device is raised, rapid construction is possible, and the characteristics of the slip form method can be improved. ,
The work of assembling, dismantling, and removing scaffolds and forms is eliminated.

[0010] When the PC strand is wound around a vertical streak to form a horizontal streak, the above-mentioned rapid construction ability is further improved.

When a tower crane is installed in a hollow steel pipe, a considerable area can be covered by the crane alone, and the number of crane installations can be reduced.

Further, when the work scaffold is attached to the tower crane so as to be able to move up and down, joining of the hollow steel pipe segments,
Each operation such as mounting of the reinforcing metal holding bracket and changing of the bracket can be performed safely and securely and efficiently.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for constructing a steel pipe / concrete composite structure pier according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a flow chart showing the procedure of a method for constructing a steel pipe / concrete composite structure pier according to this embodiment. In this embodiment, first, as shown in FIG. 2 (a), a rising portion of a hollow steel pipe 2 is erected on a foundation 1 and concrete 21 is cast inside the lower part of the hollow steel pipe 2 to form a connection with the foundation 1. And a concrete 22 is cast around the hollow steel pipe 2 using a normal formwork or the like to construct the lower skeleton 3a (FIG. 1, step 101).

The hollow steel pipe 2 has a diameter of several meters, for example.
A thickness of about 10 and a few mm is used, but it is divided into segments of a predetermined size according to the diameter and the wall thickness,
It is advisable to join these on-site by welding or high-strength bolt joining. Such a segment may be in the shape of a round slice that continues in the height direction, or may be in the form of a panel that is further divided in the circumferential direction.

Next, as shown in FIG. 2 (b), the tower crane 7 is set on the concrete 21 in the hollow steel pipe 2,
Next, the panel-shaped segment 2a of the hollow steel pipe is erected at a predetermined position by using the tower crane 7, and sequentially joined by welding or the like (FIG. 1, step 102). The joining of the segments 2a is performed using a work scaffold 42 attached to the post of the tower crane 7 so as to be able to move up and down.
In addition, the tower crane 7 is appropriately climbed along with the installation of the hollow steel pipe segment 2a, and the work platform 42 is also moved upward.

Next, as shown in FIG. 3 (a), after assembling the hollow steel pipe 2 to a predetermined height, a bracket 9 is fixed near the upper end thereof, and a sliding die is formed via a wire 41 formed of a PC steel wire or the like. The frame device 8 is suspended (FIG. 1, step 10).
3). That is, the hollow steel pipe 2 functions as a hoisting support base for hoisting the sliding formwork device 8 while supporting it.

The hollow steel pipe 2 that has been built up is fitted with a reinforcing bar holding metal fitting 12 for fixing a vertical bar to be described later at a predetermined position by welding or the like. The rebar holding metal fitting 12 may be fixed to the segment 2a of the hollow steel pipe 2 on the ground in advance, or may be mounted at a predetermined position and then attached using the work scaffold 42.

The sliding formwork device 8 is provided with a hydraulic jack (not shown) such as a center hole jack so that the entire device can be lifted by using the wire 41 as a reaction force.

Next, as shown in FIG. 3 (b), the vertical bar 5a is suspended and positioned on the reinforcing bar holding fitting 12, and
It is connected to the pre-constructed vertical streak by mechanical joint, pressure welding, etc. (FIG. 1, step 104). Before suspending the vertical streaks 5a, it is preferable to assemble them on the ground to some extent.

On the other hand, after the vertical streaks 5a have been erected, as shown in the detailed view of FIG.
The C strand 5b is unwound, and is wound by the automatic winding machine 1
4, the wire is spirally wound around the vertical streak 5a at a predetermined pitch (step 105 in FIG. 1). The steel wire reel stand 13 travels on the rails provided on the work scaffold 10 while paying out the PC strand 5b, and can orbit the hollow steel pipe 2.

The PC strand 5b is preferably wound, for example, with a diameter of about 10 mm around the vertical streak 5a at a pitch of several hundred mm. By winding such PC strands 5b, the lateral sides of the concrete are restrained to improve the compressive strength of the concrete, and at the same time, cracking, skin drop or peeling of the concrete is prevented, and the toughness up to the destruction is increased to increase the earthquake resistance. It is possible to improve the sex.

Next, as shown in FIG. 3 (b), the above-described jack is operated to raise the sliding form device 8, and at the same time, the form 11 and the hollow steel pipe 2 provided on the sliding form device 8 are connected. Continuously cast concrete in between (Fig. 1, Step 10)
6).

It is preferable that a bellows formed in a substantially circular shape in accordance with the cross-sectional shape of the pier is attached to the back of the formwork 11 so that the pressure of the concrete is supported by the bellows. .

By repeating this procedure, an intermediate skeleton 3b of the pier shown in FIG. 5 is constructed. If the height of the pier is not so high, the hollow steel pipe 2 is assembled to the design height at a time, and then the sliding formwork device is placed and concrete is cast. If the pier is high, the hollow steel pipe is used. May be performed in parallel with the concrete placing, and the bracket 9 may be rearranged upward if necessary.

Finally, as shown in the figure, the upper frame 3c adjacent to the bridge girder 4 is constructed, and the construction of the frame 3 of the pier is completed. In order to increase the integrity of the hollow steel pipe 2 and the bridge girder 4 in constructing the upper skeleton 3c, a lid or the like (not shown) is previously provided inside the upper portion of the hollow steel pipe 2 and concrete is filled above the lid. Good to do.

FIG. 6 shows the skeleton 3 constructed by the above-mentioned procedure. The substantially circular hollow steel pipe 2 is covered with concrete 31, and the concrete 3 is further covered.
In the vicinity of the surface 1, a reinforcing bar 5 composed of a vertical bar 5 a and a PC strand 5 b as a horizontal bar is arranged.

As described above, according to the method for constructing a steel pipe / concrete composite structure pier of the present embodiment, first, a hollow steel pipe is erected first, a predetermined reinforcing arrangement is performed, and then the hollow steel pipe is countered to the hollow steel pipe. Since the concrete is continuously poured while the sliding form device is raised with the force, it is possible to build the pier frame in a short period of time, enabling rapid construction of tall piers. At the same time, due to the characteristics of the slip-form method, there is no need to assemble, disassemble, or remove the work scaffold or formwork.

In particular, if the PC strand, which is a hoop line, is wound around a vertical line using an automatic winding machine or the like,
Its rapid construction ability is further improved.

The pier formed by this method has a composite structure of a hollow steel pipe and concrete, and the hollow steel pipe can bear a large bending strength and a shear strength.

Since the tower crane is installed in the hollow steel pipe, it is possible to cover a considerable area with the working radius of one tower crane. There is no need to install three units.

Also, since the work scaffold is attached to the tower crane so as to be able to move up and down, the joining of the segments of the hollow steel pipe, the attachment and detachment of the bracket for suspending the sliding formwork apparatus, and the attachment of the reinforcing steel holding bracket. Can be performed securely and efficiently.

In the present embodiment, the longitudinal bars 5a are arranged. However, if all the bending strength and the like are borne by the hollow steel pipe 2 and the main bars 5a can be substantially omitted, the process of arranging the longitudinal bars is performed. May be omitted. In the case of such a configuration, it is possible to further shorten the entire construction period by omitting complicated arrangement work of the vertical streaks.

[0034]

As described above, according to the method for constructing a steel pipe / concrete composite structure pier of the present invention, a hollow steel pipe is erected on a foundation, and then the hollow steel pipe is used as a hoisting support stand for a sliding formwork device. Then, concrete was placed inside the sliding formwork provided in the sliding formwork device to coat the surroundings of the hollow steel pipe with concrete, so that it has sufficient bending strength and shear strength. It enables rapid construction of bridge piers.

[0035]

[Brief description of drawings]

FIG. 1 is a flowchart illustrating a procedure of a method for constructing a steel pipe / concrete composite structure pier according to the present embodiment.

FIG. 2 (a) is a diagram showing how a rising portion of a hollow steel pipe is constructed, and FIG. 2 (b) is a diagram showing how a segment of the hollow steel pipe is built prior to concrete pouring.

FIG. 3 (a) is a cross-sectional view showing a state in which a sliding form device is lifted up by using a built-in hollow steel pipe as a lifting support and concrete is continuously poured, and FIG. 3 (b) is a side view of the same.

FIG. 4 is a detailed side view of the same.

FIG. 5A is a cross-sectional view of a pier formed by the method of constructing a steel pipe / concrete composite structure pier according to the present embodiment, viewed from the bridge axis direction, and FIG. Side view.

FIG. 6 is a horizontal sectional view taken along line AA of FIG. 5;

[Explanation of symbols]

 101 Building process of hollow steel pipe rising part 102 Hollow steel pipe building process 103 Sliding form placing process 104 Reinforcing process 105 PC strand winding process 106 Concrete placing process 1 Foundation 2 Hollow steel tube 3 Body 4 Bridge girder 5 Reinforcing bar 5a Vertical bar 5b PC Strand 8 Sliding formwork device 9 Bracket 12 Reinforcing metal fittings 21, 22, 31 Concrete

Claims (4)

[Claims] 1. A hollow steel pipe is erected on a foundation, then a sliding formwork device is arranged by using the hollow steel pipe as a lifting support, and concrete is then placed inside the sliding formwork provided in the sliding formwork device. A method for constructing a steel pipe / concrete composite structure pier, which comprises casting and coating concrete around the hollow steel pipe. 2. The steel pipe according to claim 1, wherein before the concrete pouring step, the PC strand is wound along the surface side of the structural cross section while surrounding the outer periphery of the hollow steel pipe.
Construction method of concrete composite structure pier. 3. The method for constructing a steel pipe / concrete composite structure pier according to claim 1, wherein a tower crane is installed in the hollow steel pipe. 4. The method for constructing a steel pipe / concrete composite structure pier according to claim 3, wherein a predetermined work scaffold is attached to the tower crane so as to be able to move up and down.