JP2003328320A - Construction method of precast capital part and bridge pier capital part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a construction method of a precast capital part and a bridge pier capital part that can considerably shorten a construction period. <P>SOLUTION: The precast capital part 10 is composed of a lower floor slab 12, an upper floor slab 11 and a web 13, and the lower floor slab 12 is provided with an opening part 14 which bridge pier main reinforcements 22 projecting from the head part of the bridge pier 20 penetrate. Reinforcement joint implements 15, 16 are embedded in the opening part side face of the lower floor slab 12, and the web 13. While the bridge pier main reinforcements 22 penetrate the opening part 14, the precast capital part 10 is installed at a bridge pier 20. Main reinforcements 18 and lateral reinforcements 31 are connected to the reinforcement joint implements 15, 16 for assembly, and concrete 50 is placed to integrate the bridge pier 20 and the precast capital part 10. <P>COPYRIGHT: (C)2004,JPO

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 precast stilt and a pier sill, and more particularly to a method for constructing a precast stilt and a pier stilt for a rigid frame bridge having a rigid connection between the pier and the pier.

[0002]

2. Description of the Related Art In the case of constructing a pier column head a of a ramen bridge, an erection bracket c is installed on the pier b after the pier b is constructed.
Is fixed, and the support work d is installed on it (Fig. 10 (A))
(Refer to Fig. 1), and support e is installed from the ground along the pier b (Fig. 1).
(Refer to 0 (B)), the rebar of the stilt a and the form f are installed,
In general, concrete is placed so that the reinforcing bars g extending from the bridge pier b to the pillar head a are rolled in, and the bridge pier b and the pillar head a are rigidly connected.

[0003]

However, in the above-mentioned conventional construction method, a large-scale bracket c and a support work d,
e, formwork f is required, and the construction of stigma a for a long time (about 3
Months). In addition, construction costs will increase significantly for long sea bridges with many spans. On the other hand, there is also a method of precasting the stilt head a to shorten the construction period, but in order to integrate the pier b and the stilt head a, it may be fixed with a PC cable or a PC rope h as shown in FIG. Conceivable. However, the stilts a made of precast blocks are
When connecting to the pier b with only the cable or the PC rope h and rigidly connecting it, the arrangement is such that it avoids the trough (support), so it is not possible to secure a sufficient arrangement space and it is difficult to integrate it with high rigidity. In many cases.

[0004]

SUMMARY OF THE INVENTION The present invention has been conceived in view of the above-mentioned conventional problems, and an object of the present invention is to provide a method for constructing a precast stilt head and a pier stilt head capable of significantly shortening the construction period. And It is another object of the present invention to provide a method for constructing a precast stilt head and a pier stilt head in which the integrity of the pier and the stilt head is improved. A further object of the present invention is to provide a method of constructing a precast stilt head and a bridge pier head which can be installed even at a long sea bridge with a large number of spans at an economical construction cost. The present invention achieves at least one of these objectives.

[0005]

In order to achieve the above object, the precast stilts of the present invention are precast stilts rigidly connected to the head of a pier, and include an upper deck and
It is composed of a lower floor slab and a web, the lower floor slab is provided with an opening through which the main rebar protruding from the head of the pier penetrates, and a reinforcing bar coupling tool is embedded in the opening side surface and the web of the lower floor slab. It will be done.

Further, the construction method of the bridge pier head portion of the present invention is
A construction method for integrating a pier and a precast pillar head, wherein the precast pillar head is installed on the pier while the main rebar protruding from the head of the pier is inserted into the opening of the precast pillar head. By connecting the rebar to the, the horizontal rebar of the column head girder and the main rebar of the lower deck slab are assembled, and the concrete is placed and the pier and the precast pier are integrated.

Here, the precast pillar head is temporarily installed on the pier, the position adjusting jack is set on the brackets provided on the pier and the precast pillar head, and the height of the precast pillar head is set by using the position adjusting jack. And the direction can be adjusted. Further, it is also possible to dispose the outer reinforcing bars on the outside of the web so as to project from the head of the pier, and to integrate the precast column heads and the outer reinforcing bars with concrete.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

<B> Structure of precast stilt head 10 (FIG. 3) The stilt head part rigidly connected to the head part (top end 21) of the pier 20 is a precast stilt head part 10 made of precast concrete manufactured in advance in a factory or a yard. is there. The precast stilt head 10 has a shape in which an upper floor slab 11 and a lower floor slab 12 are joined by a web 13. The precast pillar head 10 is installed on the top end 21 of the pier 20 to form a girder portion (see FIGS. 1 and 2).

<B> Lower floor slab 12 The lower floor slab 12 is provided with an opening 14. The opening 14 includes a large number of main reinforcements 22 for bridge piers (hereinafter referred to as main reinforcements 22) projecting upward from the top end 21 of the pier 20.
It is for penetrating inside 0, and has a size capable of penetrating these main reinforcing bars 22. A plurality of reinforcing bar fittings 15 are embedded in the side surface of the opening 14. As the reinforcing bar joint tool 15, for example, a screw type reinforcing bar joint can be used. This screw type rebar joint 15 is connected to the main rebar 18 for the lower floor slab (hereinafter referred to as the main rebar 18
) Are connected, the main reinforcing bars 18 are arranged in the lower floor slab 12 separated by the opening 14, and the lower floor slab 12 is post-struck.

<C> Web 13 The web 13 is arranged between the lower floor slab 12 and the upper floor slab 11 and substantially parallel to the direction of action of the load. Web 13
In the vertical direction, a plurality of rebar joint fittings 16 are embedded in front and rear two rows (see FIG. 1). As the reinforcing bar joint tool 16, for example, a screw type reinforcing bar joint can be used as described above. The screw-type reinforcing bar joint 16 connects a lateral reinforcing bar 31 for constructing a transverse beam 30 described later.

<D> Main Reinforcing Bar 22 for Pier The main reinforcing bar 22 projects upward from the top end 21 of the pier 20.
Therefore, when the precast stilts 10 are installed on the piers 20, the main reinforcing bars 22 penetrate into the precast stilts 10. The main rebars 22 project near the inside of the upper floor slab 11 and are orthogonal to the lateral rebars 31 and serve as RC structural members of the cross beam 30.

<E> Position adjusting jack 40 The bracket 23 is attached to the upper portion (near the top end 21) of the pier 20 and the position adjusting jack 40 is installed. The position adjusting jack 40 is, for example, of a hydraulic drive type, has a jack main body and a telescopic plunger 41, and the telescopic plunger 41 is directed vertically upward.
The lower end of the jack body is fixedly installed on the bracket 23. The bracket 17 is attached downward to the web 13 of the precast stilt head 10. The bracket 17 is in contact with the telescopic plunger 41 and can support the precast pillar head 10 by driving the position adjusting jack 40.
The height and direction of the precast stilt head 10 can be adjusted.

Next, a method of constructing the pier column head will be described.

<A> Manufacturing of precast stilts 10 The precast stilts 10 are manufactured in a factory or a yard. An opening 14 is provided in the lower floor slab 12 of the precast pillar head 10, and the lower floor slab 12 and the web 13 are preliminarily provided with the reinforcing bar fittings 15, 1.
6 is buried. The bracket 17 is attached to the web 13 downward (FIG. 4 (A)). Further, a bracket 23 for installing the position adjusting jack 40 is attached near the top end 21 of the pier 20 (FIG. 4 (A)).

<B> Temporary installation of the precast pillar head 10
(FIG. 4 (B)) The precast pillar head 10 is transported to the site, and although not shown, the precast pillar head 10 is hung by a crane or the like and temporarily installed on the top end 21 of the pier 20. Precast Pillar 1
When 0 is lowered by the crane, the main reinforcing bar 22 protruding upward is penetrated into the precast stilt head 10 through the opening 14. In the case of a long sea bridge, a crane ship is used for offshore work.

<C> Adjustment by the position adjusting jack 40
(FIGS. 5 (A) and 5 (B)) The position adjusting jack 40 is set on the brackets 17 and 23 so that the telescopic plunger 41 is directed vertically upward. The position adjusting jack 40 is driven, and the telescopic plunger 41 is inserted through the bracket 17 into the precast pillar head 10.
While supporting, adjust the height and direction of the precast stigma 10.

<D> Assembly of main rebar 18 and lateral rebar 31
(FIGS. 6 (A) and 6 (B)) The main rebar 18 is connected to the reinforcing bar joint 15 which is embedded in the side surface of the opening 14 of the lower floor slab 12 in advance, and the lower floor is separated by the opening 14. The main reinforcing bars 18 are arranged on the plate 12.
In addition, the reinforcing bar joint tool 16 embedded in the web 13 in advance
The horizontal rebar 31 is connected to. The transverse reinforcing bars 31 intersect the main reinforcing bars 22, and the reinforcing bars for constructing the cross beam 30 are assembled. By arranging the transverse reinforcing bars 31 and the main reinforcing bars 22 so as to intersect with each other, the stress due to the load can be widely distributed.

<E> Placing concrete 50 (Fig. 7)
(A) and FIG. 7 (B)) Concrete 50 is placed on the lower floor slab 12 and the cross girder 30 in which the main rebars 18 and the lateral rebars 31 are assembled. Lower floor version 12
Concrete 50 placed in the opening 14 of the
It becomes integral with the top end 21 of the, and the precast pillar head part 10 and the pier 20 are integrated. In this way, if the precast pillar head 10 and the pier 20 are integrated, for example, a mobile work carriage in which the formwork and the support work are integrated is installed on the precast pillar head 10, and the mobile work carriage is removed from the precast pillar head 10. It is possible to construct a PC cantilever bridge overhanging.

Since the precast stilt head 10 of the present invention is manufactured in advance in a factory, it does not require a formwork on site and is excellent in quality as compared with the cast-in-place concrete method. Further, since the precast pillar head 10 is used, the construction of the pier 20 and the production of the precast pillar head 10 can be performed in parallel work, and the construction period can be greatly shortened to one third or less. Furthermore, according to the method of constructing the pier stilt head of the present invention, since the position adjusting jack 40 that is sufficient to support only the load of the precast stilt head 10 is installed, there is an advantage that the temporary structure can be relatively small.

[0021]

Embodiment 2 When a large force is applied in the direction perpendicular to the bridge axis (transverse direction orthogonal to the bridge axis), an outer reinforcing bar 24 projecting from the pier 20 can be arranged outside the web 13. That is, as shown in FIG. 8, circular arc portions 25 are provided on both sides of the pier 20, and the outer reinforcing bar 2 is provided from the top end 21 of the circular arc portion 25.
4 is projected upward (one arc portion 25 and the outer reinforcing bar 24 are hidden by the block 10A and cannot be seen in the figure). The precast stilt head 10 is divided into two blocks 10A and 10B and installed on the pier 20 so that the outer reinforcing bars 24 are located outside the web 13. In addition, precast stigma 1
The 0 may not be divided into two blocks and may remain as one unit. Outer reinforcement 24 and web 50 with concrete 50
Are placed and integrated (see FIG. 9). The first embodiment
Similarly, the main rebars 18 of the lower floor slab 12 and the lateral rebars 31 of the cross girders 30 are assembled and concrete 50 is placed to integrate the precast pillar heads 10 and the piers 10. In this example, since the circular arc portion 26 of the RC structure is formed so as to project on the precast pillar head 10, the integration is further enhanced and a large force in the direction perpendicular to the bridge axis can be resisted. The protruding shape is
The shape is not limited to the circular arc portions 25 and 26, and may be, for example, a rectangular shape.

[0022]

Since the present invention is as described above, the following effects can be obtained. <B> Because it is a precast pillar head, it is possible to construct bridge piers and precast pillar heads in parallel by prefabricating them in a factory or yard, and it is possible to shorten the construction period to a third or less. <B> Because of the RC structure in which the main reinforcing bars protruding from the head of the pier, the transverse reinforcing bars of the girder, and the main reinforcing bars of the lower deck are connected,
It is possible to provide a method of constructing a precast stilt head and a pier stilt head in which the integrity of the precast stake head and the pier is improved. <C> Normally, large-scale brackets and supporting work are required to construct the stilts of a ramen bridge. However, according to the construction method of the present invention, it is only necessary to mount an adjustment jack, so a temporary structure is required. Small scale is enough. <D> When applied to a long sea bridge with many spans,
Construction costs are extremely economical.

[Brief description of drawings]

FIG. 1 is a perspective view showing a cross section of a part of a precast column head installed on a pier.

FIG. 2 is a perspective view showing a state in which a pier and a precast pillar head are integrated.

FIG. 3 is a perspective view of a precast pillar head.

FIG. 4A is an explanatory diagram showing a precast stilt head and pier before temporary installation, and FIG. 4B is an explanatory diagram showing a precast stilt head and pier after temporary installation.

5A and 5B are explanatory views showing position adjustment by a position adjustment jack, in which FIG. 5A is a partially sectional side view and FIG. 5B is a sectional front view.

FIG. 6 is an explanatory view showing a state in which rebars are assembled, (A) is a side view, and (B) is a front view with a part thereof cross-sectioned.

FIG. 7 is an explanatory view showing a state where concrete is poured,
(A) is a side view, (B) is a cross-sectional front view.

FIG. 8 is a perspective view showing a precast stud and a pier in another embodiment.

FIG. 9 is a perspective view showing a state in which a pier and a precast pillar head are integrated in another embodiment.

FIG. 10 is an explanatory view of the related art, (A) is a diagram showing a bracket system, and (B) is a diagram showing a fixed support system.

FIG. 11 is an explanatory view showing a construction example of a conventional precast stilt head.

[Explanation of symbols]

10 ... Precast stigma 12 ... Lower floor version 13 ... Web 14 ... Opening 15, 16 ... Reinforcing bar fittings 18 ... Main rebar 20 ... Pier 22 ... Main rebar (main rebar for bridge pier) 24 ... Outer rebar 25, 26 ... Arc part 31 ... Lateral rebar 40 ... Jack for position adjustment 41 ... Telescopic plunger

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masakazu Horiguchi             1-25-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo Taisei             Construction Co., Ltd. (72) Inventor Hidehiko Inahara             1-25-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo Taisei             Construction Co., Ltd. F term (reference) 2D059 AA03 AA08 AA14 BB39 CC03                       CC04 CC06 DD06 GG55

Claims (4)

[Claims] 1. A precast stilt head rigidly connected to the head of a pier, comprising a top slab, a bottom slab, and a web, wherein the bottom slab has main rebars protruding from the head of the pier. A precast stilt head, which is provided with an opening penetrating therethrough, and in which a reinforcing bar joint tool is embedded in the opening side surface and the web of the lower floor slab. 2. A method for constructing a pier sill head that integrates a pier and a precast stilt head, wherein the precast stilt head according to claim 1 is provided with a main rebar protruding from the pier head. Install on the pier while penetrating, connect the rebar to the rebar joint tool, assemble the transverse rebar of the pillar head girder and the main rebar of the lower deck slab, and place the concrete to pier the pier and precast pillar head. This is a method of constructing the pier column head that is integrated. 3. The method of constructing a pier pole head according to claim 2, wherein the precast pier head is temporarily installed on the pier, and the position adjusting jacks are set on the brackets provided on the pier and the precast pier head, and the position is set. A method of constructing a pier column head, characterized in that the height and direction of the precast column head are adjusted using an adjusting jack. 4. The method of constructing a pier column head according to claim 2 or 3, wherein an outer reinforcing bar projecting from the head of the pier is arranged outside the web, and the outer reinforcing bar and the precast column head are made of concrete. A method of constructing a pier column head, characterized by being integrated.