JP2011042997A - Method for constructing joint between column and foundation, and method for arranging ring reinforcement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To arrange a ring reinforcement around an erected steel frame without setting up a scaffold etc. <P>SOLUTION: In this method for constructing a joint of a foundation structure 20 in which a bridge pier 10 of concrete construction internally undergoing the embedment of a vertically-elongated steel pipe 30 and the lower end of the bridge pier 10 are connected together, a prefabricated bar 40 is constructed by connecting the annular ring reinforcements 42 at spacings by means of a vertical reinforcement 41; the end of the steel pipe 30 is inserted into the prefabricated bar 40; the prefabricated bar 40 is fixed to the steel pipe 30; a lower section of the foundation structure 20 is constructed; the steel pipe 30 is erected on the lower section of the foundation; concrete constituting an upper section of the foundation structure 20 is poured; and concrete constituting the bridge pier 10 is poured. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  In the present invention, for example, a method for constructing a connection portion between a pillar and a foundation in which a steel frame such as a pier is embedded and a plurality of ring bars are embedded so as to surround the lower end of the steel frame, and the ring bars are arranged around the steel frame. It relates to the method of making a line.

  Conventionally, as a method of constructing piers, a plurality of steel pipes are erected in the vertical direction at positions corresponding to the inside of the piers, and vertical main bars are arranged around these steel pipes, and the vertical main bars are surrounded. As described above, a hybrid slip foam method is used in which a PC strand is wound and a reaction force is taken at the upper end of the steel pipe to raise the slip foam, and concrete is placed in the slip foam to construct a pier ( For example, see Patent Document 1).

  In the pier constructed by the above construction method, a large load acts on the concrete constituting the foundation around the lower end of the steel pipe. For this reason, in order to reinforce the concrete around the steel pipe, the lowermost steel pipe is erected, and then an annular ring bar is arranged around the concrete steel pipe.

  Conventionally, the ring reinforcement work is performed on the scaffold by assembling a scaffold around the lowermost steel pipe. However, in such a method, assembling and dismantling work of the scaffold is time-consuming, and when a rectangular scaffold material is used, there is a gap between the steel pipe and the scaffold, resulting in work restrictions and workability. It was damaged.

  Therefore, as a ring reinforcement arrangement method, in order to improve workability, for example, as described in Patent Document 1, a plurality of hoop reinforcements are connected in advance by a vertical reinforcement and assembled into a cylindrical shape, It is conceivable to apply a method of building this cylindrical assembly rebar so that a steel pipe is inserted therein.

Japanese Patent Laid-Open No. 11-152899

However, in the above method, the assembled rebar needs to be lifted and built by a crane, but the gap between the assembled rebar and the steel pipe is narrow, and when the assembled rebar is built, an operator can assemble it at the upper part of the steel pipe. Since it is necessary to adjust the position of the reinforcing bar, work at high places will occur.
In addition, a support member for supporting a scaffold provided around the steel pipe is usually protruded from the surface of the upper part of the steel pipe during welding work, and this support member interferes with the assembly rebar when building the assembly rebar. Resulting in.

  The present invention has been made in view of the above problems, and an object of the present invention is to enable ring reinforcement to be arranged around a steel frame embedded in a pillar without assembling a scaffold or the like.

  The method for constructing a pillar-to-foundation connecting portion according to the present invention is a concrete pillar in which a steel frame extending in the vertical direction is embedded, and a foundation connecting portion to which the lower end of the pillar is connected, Reinforcing bar assembling step for assembling a cylindrical assembling rebar by fixing a plurality of ring bars with vertical bars spaced apart from each other; and Relative movement of the steel frame, and in this state, the fixing step of fixing the assembled rebar to the steel frame, the foundation lower part construction step of constructing the lower part of the foundation, and the foundation on which the constructed steel frame is fixed A step of erection on the lower part of the foundation, a step of constructing the upper part of the foundation for placing the concrete constituting the upper part of the foundation, and a concrete placing for placing the concrete constituting the column A step, characterized in that it comprises a.

In the above-described method for constructing the connection portion between the pillar and the foundation, the fixing step may be performed in a state where the steel frame is laid sideways, and the pillar may be a bridge pier.
Further, in the fixing step, the assembled reinforcing bar and the steel frame may be relatively moved while the steel frame is laid down, and the assembled reinforcing bar may be fixed to the steel frame in this state. In the concrete placing step, concrete may be placed using slip foam.

Also, the ring reinforcement arrangement method of the present invention is a method of arranging a plurality of ring reinforcements at intervals in the vertical direction so as to surround a steel frame erected in the concrete so as to extend in the vertical direction. A rebar assembling step for assembling a cylindrical rebar by fixing the plurality of ring bars to the vertical bars at intervals, and the assembly rebar so that the end of the steel frame is inserted into the rebar And a step of fixing the assembled rebar to the steel frame in this state, and a step of building the steel frame to which the assembled rebar is fixed.
In the above-described ring reinforcement arrangement method, the fixing step may be performed in a state where the steel frame is laid sideways.

  According to the present invention, since the steel frame is built in a state where the end of the steel frame is inserted into the assembled steel frame assembled in a cylindrical shape in advance and the assembled reinforcing bar and the steel frame are fixed, the ring reinforcement is arranged. A work scaffold is not required.

The column base part of the pier constructed | assembled applying the ring reinforcement arrangement method of this embodiment is shown, (A) is a vertical sectional view, (B) is a horizontal sectional view. It is FIG. (1) for demonstrating the construction method of a pier. It is FIG. (2) for demonstrating the construction method of a pier. It is FIG. (3) for demonstrating the construction method of a pier. It is FIG. (4) for demonstrating the construction method of a pier. It is a figure (the 1) which shows the method of attaching an assembly reinforcing bar to a steel pipe. It is a figure (the 2) which shows the method of attaching an assembly reinforcing bar to a steel pipe.

Hereinafter, an embodiment of a ring reinforcing method according to the present invention will be described in detail with reference to the drawings.
1A and 1B show a base 11 of a pier 10 constructed by applying a method for arranging ring bars 42 according to the present embodiment, in which FIG. 1A is a vertical sectional view and FIG. 1B is a horizontal sectional view. In FIG. 1A, the left half shows the II cross section in FIG. 1B, and the right half shows the II-II cross section. As shown in the figure, the pier 10 is provided with a steel pipe 30 embedded in a state where a plurality of steel pipes 30 are vertically connected in a concrete member 12 constructed in a substantially rectangular column shape, and is arranged on the outer periphery of the plurality of steel pipes 30. The plurality of vertical bars 51, and the PC strands 52 wound so as to surround the plurality of steel pipes 30 and the vertical bars 51 from the outer peripheral side. The steel pipes 30 are arranged in a plurality of rows vertically and horizontally in the concrete member 12 in plan view.

  The lowermost steel pipe 30 has a lower portion embedded in the foundation structure 20, and the lower outer circumferential surface of the lowermost steel pipe 30 has unevenness in order to improve adhesion strength with the concrete 21 constituting the foundation. It is formed (hereinafter, this portion is referred to as an uneven portion forming portion 31). An assembly reinforcing bar 40 including a plurality of ring bars 42 and vertical bars 41 connecting the ring bars 42 is arranged so as to surround the periphery of the unevenness forming part 31.

Hereinafter, the construction method of this pier is demonstrated, referring FIG. 2A-FIG. 2D and FIG.
First, as shown in FIG. 3A, a plurality of ring bars 42 are arranged at intervals in the vertical direction and assembled so as to be held by the vertical bars 41 to construct an assembled reinforcing bar 40.
Next, as shown in FIG. 3 (B), the lowermost steel pipe 30 is laid on the holding member 110 so that a gap is formed between the concavo-convex forming portion 31 below the steel pipe 30 and the ground surface. Hold.

  Next, as shown in FIG. 3 (C), the assembly rebar 40 is moved in the horizontal direction so that the unevenness forming portion 31 of the lowermost steel pipe 30 is disposed inside. Then, as shown in FIG. 4, at least in the upper and lower parts of the assembly reinforcing bar 40, a space 61 is provided between the vertical bar 41 and the surface of the steel pipe 30 in the circumferential direction. The spacer 61 is attached to the steel pipe 30 by welding. Further, a setup bar 60 bent in an L-shape is welded to the surface of the steel pipe 30, and the vertical bar 41 of the assembly reinforcing bar is fixed to the setup bar 60 with a binding wire or the like.

  In parallel with the above steps, as shown in FIG. 2A, a portion of the foundation structure 20 up to a depth corresponding to the lower end of the steel pipe (hereinafter referred to as a foundation lower portion 20A) is constructed. The construction work of the lower foundation 20A is performed by excavating the ground to form the excavation hole 22, placing a reinforcing bar in the excavation hole 22, and then placing the concrete 21 to a predetermined depth.

  Next, the lowermost steel pipe 30 with the assembled rebar 40 attached is installed on the upper part of the foundation lower part 20A. At this time, since the assembled rebar 40 is connected to the steel pipe 30 via the setup bar 60, the assembled rebar 40 does not fall even when the steel pipe 30 is raised substantially vertically, and the assembled rebar 40 and the steel pipe 30 are not dropped. Since the spacer 61 is interposed therebetween, the gap between the assembled reinforcing bar 40 and the steel pipe 30 is maintained.

  Next, as shown in FIG. 2B, the steel pipes 30 are sequentially connected upward. The steel pipe 30 is connected by first placing a new steel pipe 30 above the already built steel pipe 30, temporarily fixing it in place using a temporary fixing jig, and temporarily fixing the steel pipe 30 up and down. This is performed by welding between 30. In addition, the vertical bars 51 are arranged so as to surround the steel pipe 30 in parallel with the connection work of the steel pipe 30.

  After the connection work of the uppermost steel pipe 30 is completed, a work scaffold is provided in the uppermost steel pipe 30, and a plurality of ring bars are wound around the steel pipe 30 corresponding to the column head on the work scaffold at intervals in the vertical direction. . In addition, a ring line | wire is formed in the periphery shape and has a shape which an edge part overlaps, and it can attach to the circumference | surroundings of the steel pipe 30 by letting the steel pipe 30 pass between this overlapped parts.

  Next, as shown in FIG. 2C, a reaction force stand 200 is provided on the uppermost portion of the steel pipe 30, and the slip foam device 210 is installed so as to be suspended by the reaction force stand 200. Note that a delivery device 220 for winding the PC strand 52 is provided on the slip foam device 210.

Next, the PC strand 52 is wound around the longitudinal bars 51 in the upper part while the slip foam device 210 is raised. In parallel with this, the slip foam apparatus 210 is used as a mold, and the slip foam apparatus 210 is raised while placing concrete around the portion where the PC strand 52 is wound. After the concrete placement to the top of the pier 10 is completed and the placed concrete is hardened, as shown in FIG. 2D, the slip foam device 210 is lowered to the ground level and removed, and the reaction force platform 200 is removed. Is removed by the crane 100.
The construction work of the pier 10 is completed by the above steps.

  According to the present embodiment, since the assembly rebar 40 formed in a cylindrical shape is fixed in a state where the lowermost steel pipe 30 is laid down, a work scaffold becomes unnecessary, and workability can be improved. For this reason, work in high places does not occur and construction can be performed safely.

  Moreover, since the assembly rebar 40 can be assembled and attached to the steel pipe 30 in advance, the labor of bar arrangement can be reduced.

  In the present embodiment, when the pier 10 is constructed by the hybrid slip foam method, the case where the ring bars 42 are arranged around the lowermost steel pipe 30 has been described as an example. The present invention can be applied when it is necessary to stand and arrange the ring bars 42 around the steel pipe 30.

  Moreover, in this invention, although the case where the ring reinforcement 42 was arrange | positioned around the steel pipe 30 was demonstrated, it is applicable not only to this but when a ring reinforcement is arrange | positioned around H-shaped steel or square steel. The shape of the ring line is not limited to an annular shape, and may be a rectangular shape.

DESCRIPTION OF SYMBOLS 10 Pier 11 Pillar base 12 Concrete member 20 Foundation structure 21 Concrete 22 Drilling hole 30 Steel pipe 40 Reinforcement bar 41 Vertical bar 42 Ring bar 51 Vertical bar 52 PC strand 60 Set-up bar 61 Spacer

Claims (7)

A concrete column in which a steel frame extending in the vertical direction is embedded inside, and a construction method of a connecting portion of a foundation to which the lower end of the column is connected,
A rebar assembly step for assembling a cylindrical assembly rebar by fixing a plurality of ring bars with vertical bars spaced apart from each other;
A fixing step of relatively moving the assembled rebar and the steel frame so that an end of the steel frame is inserted into the assembled rebar, and fixing the assembled rebar to the steel frame in this state;
A foundation lower part construction step for constructing a lower part of the foundation;
A build-in step of building the steel frame on which the assembly rebar is fixed on the lower part of the constructed foundation;
A foundation upper construction step for placing concrete constituting the upper part of the foundation;
A concrete placing step for placing concrete constituting the pillar, and a method for constructing a connecting portion between the pillar and the foundation. A method for constructing a connecting portion between a pillar and a foundation according to claim 1,
The fixing step is performed in a state where the steel frame is laid down sideways.   The method for constructing a connection portion between a pillar and a foundation according to claim 1, wherein the pillar is a pier.   2. The fixing step includes interposing a spacer between the steel frame and the assembled reinforcing bar, attaching a setup bar to the steel frame, and fixing the setup bar and the assembled reinforcing bar. The construction method of the connection part of the pillar and foundation of any one of 3 to 3.   5. The method for constructing a pillar-to-foundation connection part according to claim 1, wherein in the concrete placing step, concrete is placed using slip foam. It is a method of arranging a plurality of ring bars at intervals in the vertical direction so as to surround a steel frame erected so as to extend in the vertical direction in the concrete,
Rebar assembling step for assembling a cylindrical assembling rebar by fixing the plurality of ring rebars to the vertical rebars at intervals;
A fixing step of relatively moving the assembled rebar and the steel frame so that an end of the steel frame is inserted into the assembled rebar, and fixing the assembled rebar to the steel frame in this state;
And a laying step for building the steel frame to which the assembly reinforcing bar is fixed. A ring reinforcement method according to claim 6,
The method of arranging a ring muscle, wherein the fixing step is performed with the steel frame lying on its side.

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