JPH0742114A - Construction method for concrete-filled steel pipe multi-pillar type bridge pier - Google Patents

Abstract

PURPOSE:To safely construct a bridge pier in a short period with no reinforcing bar assembling work at a high position by combining a plurality of commercial standard steel pipes, and placing concrete into them. CONSTITUTION:Short foundation steel pipes are upright installed for the foundation of a bridge pier. Concrete is placed around them to construct the foundation. Short connecting steel pipes l are connected above the buried foundation steel pipes. Lateral bracings serving as horizontal members and braces serving as diagonal members are fitted to the connecting steel pipes in advance. When the connecting steel pipes 1 are fitted, adjacent lateral bracings and braces are connected together. Long steel pipe pillars 2 are hung above the connecting steel pipes 1 with a crane or the like, and end faces are welded together. The connecting steel pipes 1 and the steel pipe pillars 2 are stacked in turn. When they reach the desired height, concrete is pressed into a steel pipe group to complete the bridge pier.

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 concrete-filled steel pipe multi-column type bridge pier.

[0002]

2. Description of the Related Art Conventionally, when constructing a bridge pier, a method has been adopted in which the work of assembling a formwork and placing concrete inside thereof is repeated to start up. Namely scaffold assembly, rebar assembly, formwork assembly,
The method was to repeat the work of placing concrete, curing concrete, demolding the formwork, and reassembling the scaffolding.

[0003]

[Problems to be Solved by the Invention] The above-mentioned conventional method of constructing a bridge pier has the following problems. <A> In order to assemble the formwork and rebar up to a high place and start it up, and to pour concrete, it is necessary to assemble scaffolds around it, which is a great deal of work. <B> Assembling the formwork and the reinforcing bar is dangerous because it involves working in high places. In particular, there is a shortage of skilled workers, which may cause deterioration of quality in work at high places, which is uneasy. <C> Assembling a reinforcing bar and assembling a formwork is the most troublesome work and affects the process. However, it is difficult to shorten the work period because the conventional method cannot save labor.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned conventional problems, and minimizes the work at dangerous heights, and the laborious rebar assembly and formwork assembly work. It is an object of the present invention to provide a bridge pier construction method that can be omitted to shorten the process.

It is another object of the present invention to provide a method for constructing a bridge pier with a small cross section and a high yield strength by compensating the weak points of the respective materials of concrete and steel pipe.

[0006]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the method for constructing a concrete-filled steel pipe multi-column type bridge pier of the present invention is a structure in which a horizontal structure or a brace is attached to a short hollow steel pipe. Using a steel pipe and a long hollow steel pipe,
The structure steel pipe and steel pipe columns are alternately connected to the upper part of the foundation steel pipe vertically embedded in the foundation to raise the bridge pier, the concrete is pressed into the steel pipe from the lower end, and the steel pipe is filled with concrete. It is characterized by the construction method of concrete-filled steel pipe multi-column type piers.

[0007]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of a method for constructing a concrete-filled steel pipe multi-column type bridge pier according to the present invention will be described below with reference to the drawings.

<A> Member to be used In the construction method of the present invention, a general assembly form and assembly rebar are not used. Use steel pipes instead. The steel pipe consists of a short steel frame pipe 1 and a steel pipe column 2 having a longer length.
And are used in combination.

<B> Structure Steel Pipe 1 The structure steel pipe 1 has a structure in which a horizontal structure 11 as a horizontal member and a brace as a diagonal member are attached to the side surface of a hollow steel pipe having a short length. A steel pipe having a slightly smaller diameter is attached to the upper and lower ends of the fine steel pipe 1 so as to be jointed with the steel pipe column 2. The role of the horizontal structure and the brace is to reduce the buckling length of the steel pipe column 2 and to ensure the stability of the entire structural system.

<C> Steel Pipe Column 2 As the steel pipe column 2, a steel pipe having a length longer than that of the structural steel pipe 1 is used. The inside is also hollow and has the same diameter as the fine steel pipe 1. A scaffold 21 for work is provided around the upper end of the steel pipe column 2.
Is fixed. Furthermore, in some cases, reinforcing bars may be assembled in the internal space.

<D> Construction of foundation A short foundation steel pipe 3 is installed vertically on the foundation of the pier,
Concrete is cast around it to build the foundation. The diameter of the basic steel pipe 3 is the same as the structure steel pipe 1 and the steel pipe column 2 described above.
Use a diameter equal to the diameter of.

<E> Connection of Steel Pipe The above-mentioned steel structure pipe 1 is connected to the upper part of the basic steel pipe 3 vertically embedded in the foundation. A horizontal frame 11 and a brace are attached to each of the steel frame pipes 1 in advance. Therefore, when a large number of steel frame pipes 1 are attached, adjacent horizontal frames 11 and braces are connected to each other.

Next, the steel pipe column 2 is attached to the upper part of the steel pipe structure 1. The steel pipe pillar 2 is set on the fine steel pipe 1 by a crane. And the mutual welding work is performed on the steel pipe pillar 2
The scaffold 21 provided on the upper part of the
Since No. 1 is also installed in the factory in advance, it is faster and more reliable than the conventional method of scaffolding on site.

In this way, the structural steel pipe 1 and the steel pipe column 2 are attached to each other and rise vertically. At the height of the steel pipes 1, the adjacent steel pipes 1 are integrated with each other, so that the steel pipes 1 can be firmly assembled.

Then, a group of steel pipes is assembled, and a frame 4 for a bridge seat is attached to the uppermost part thereof. The bridge form 4 is composed of a bottom plate and side plates that surround the periphery thereof. Since this form can also be attached to the uppermost part of the steel pipe column 1 in advance at the factory, it is possible to improve the size and quality. High reliability can be expected.

When all the preparations are completed in this way, concrete is press-fitted into the steel pipe group from the lower end of the base steel pipe 3 or the structural steel pipe 1. As the press-fit concrete, known concrete having good fluidity such as concrete called high performance concrete can be used. In this way, concrete is pushed up from below to fill the inside of the fine steel pipe 1 and the steel pipe column 2.

For high piers that cannot be press-fitted, concrete may be poured into the steel pipe from above by a tremie pipe using the bridge seat portion. When the pouring of concrete is completed, the rebar cages assembled in the factory are lifted inside the bridge form 4 and set inside, and the concrete is filled.

[0018]

The method for constructing a concrete-filled steel pipe multi-column type pier according to the present invention is as described above, so that the following effects can be obtained. <a> Concrete is a method of filling the inside of a steel pipe that has already been installed vertically. Therefore, on-site formwork assembly and dismantling work are unnecessary. In this way, it is possible to efficiently shorten the process without assembling and disassembling the mold in a dangerous high place as in the past.

<B> By filling the inside of the steel pipe with concrete, the concrete portion bears a compressive force, and the steel pipe portion bends and pulls a tensile force. Therefore, as a reinforced concrete structure, the work of assembling the reinforcing bar can be omitted. Even when adopting the SRC structure, if the rebar is built in the steel pipe in advance,
Reinforcement work on site is hardly required.

<C> For concrete, a method of press-fitting from below the steel pipe is adopted. Therefore, as compared with the conventional method of placing concrete repeatedly at each assembling height of the formwork, the number of days of placing is reduced and the compacting work is not required.

<D> In this method, a factory-produced steel pipe, which is a commercially available standard product, is used instead of the formwork assembled on site. Therefore, good quality can be secured as compared with the formwork assembled on site.

<E> The work requiring a scaffold is only for the joint portion of the steel pipe. Therefore, the scaffold can be attached to the steel pipe in advance, and the work of assembling the scaffold can be omitted.

<F> The formwork of the bridge seat portion can also be previously fixed integrally with the steel pipe, and the formwork can be made of a steel plate. Therefore, it is possible to omit the work of assembling the mold and demolding.

<G> By adopting the above-mentioned structure, the self-weight can be reduced as compared with the conventional RC structure. Therefore, the structure and dimensions of the foundation can be reduced, which is economical.

<H> Concrete prevents local buckling of the steel pipe, while the steel pipe acts to restrain the concrete and give the confined effect to obtain higher compressive strength.
In this way, concrete and steel pipes complement each other's weaknesses, so that a pier with a small cross-section and high yield strength can be constructed.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of the order of a construction method of the present invention.

FIG. 2 is an explanatory diagram of the order of the construction method of the present invention.

FIG. 3 is an explanatory diagram of the order of the construction method of the present invention.

FIG. 4 is an explanatory diagram of the order of the construction method of the present invention.

FIG. 5 is an explanatory view of the order of the construction method of the present invention.

FIG. 6 is an explanatory diagram of the order of the construction method of the present invention.

Claims (2)

[Claims] 1. A structure steel pipe, which comprises a short and hollow steel pipe with a horizontal structure and braces attached to it, and a steel pipe column composed of a long and hollow steel pipe, which is vertically embedded in a foundation. The method of constructing a concrete-filled steel pipe multi-column type pier, in which the pier is started by alternately connecting the 2. A hollow steel pipe having a horizontal structure and braces attached thereto and a hollow steel pipe having a long hollow are used, and a steel pipe and a steel pipe column are provided above a basic steel pipe vertically embedded in a foundation. Alternately connect the bridges to raise the pier, attach the bridge formwork to the top, fill the steel pipe inside with concrete, and then fill the bridge formwork with concrete. Pillar pier construction method