JP2006144533A - Precast prestressed reinforced concrete bottom plate, bridge provided with it, and execution method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a precast prestressed reinforced concrete bottom plate which can be easily adapted to a bridge of large bridge width because of ease in transportation and handling. <P>SOLUTION: A reinforced concrete slab is divided and installed on the casting mold 100 of the bridge in the bridge axis direction and the direction at right angles to the bridge axis. Then both ends of the reinforced concrete slab are placed on the casting mold, and are integrated with the casting mold. Then at least one or more sheath pipe 204 is buried to which prestressed concrete strand is inserted from outside in the direction at right angles to the bridge axis within the slab. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a precast prestressed reinforced concrete bottom plate, a bridge provided with the same, and a construction method thereof.
In particular, it is mounted separately on the bridge mold in the bridge axis direction and the bridge axis perpendicular direction, both ends are placed on the mold and integrated with the mold, and at least the PC strand is inserted into the main body from the outside in the bridge axis perpendicular direction. The present invention relates to a precast prestressed reinforced concrete bottom plate in which one or more sheath pipes are embedded.

In a conventional bridge, in order to provide a bottom plate on a bridge mold, a formwork is manufactured on site, a reinforcing bar is placed on the formwork, concrete is placed on it, and after a long period of concrete curing, the baseplate is preloaded. The bottom plate was completed by introducing stress.
However, the conventional bridge construction method as described above has difficulty in quality control due to on-site production of the bottom plate, and requires a lot of time for formwork production, concrete curing, etc., so that the construction period is prolonged. There was a problem. In addition, the number of construction personnel has increased due to the reinforcement of the rebars at the site. Especially when building bridges in the city center, a large work space is required for many site operations. There were problems such as the occurrence of traffic obstacles.

  In order to solve the above problems, a precast prestressed reinforced concrete bottom plate bridge was developed. In this bridge, after manufacturing a bottom plate made of reinforced concrete slab in advance, not at the site, carrying it to the bridge construction site and placing it on the bridge mold, introducing prestress and integrating the bottom plate, The bridge was completed by placing a shearing joint and synthesizing the bottom plate and the mold.

In order to solve such a problem, in Patent Document 1 below, a protective wall installation portion to which a protective wall fixing steel rod inserted and inserted into the protective wall is fixed at both lateral ends of the bottom plate is formed. The bottom plate is configured with a recess so that the end of the longitudinal tension member arranged in the bottom plate is exposed and tensioned by a hydraulic jack, and the longitudinal tension member is tensioned and fixed by the hydraulic jack. After that, the hydraulic jack installation part filled with the filler is formed, and the side of the bottom plate is filled with resin to prevent the end of the tensioned lateral tension material from coming into contact with the outside air A precast reinforced concrete bottom plate in which a recess is formed is disclosed.
Republic of Korea Published Patent No. 2001-45640

However, according to the above technique, there are many disadvantages.
First of all, when the bridge width is very large, for example, for bridges with a width of 10 m or more, the bottom plate may exceed the capacity of the transportation equipment, which may make transportation impossible, and handling on site There is a problem that it becomes difficult.
Further, since the lateral tension members are arranged in a straight line, they cannot efficiently cope with the bending moment and the shearing force.

Further, when the mold and the bottom plate are joined, a shear stud and a stud fixing groove should be provided and a non-shrink mortar should be used, so that workability is poor and uneconomical. In addition, sliding may occur between the mold and the bottom plate.
In addition, in order to obtain unity between adjacent bottom plates, bridge axial prestress should be introduced, which complicates the work and makes it uneconomical.

Accordingly, an object of the present invention is to provide a precast prestressed reinforced concrete bottom plate that can be easily applied to a bridge having a large bridge width due to ease of transportation and handling.
Another object of the present invention is to provide a precast prestressed reinforced concrete bottom plate that can efficiently cope with tensile stress and compressive stress.
Another object of the present invention is to provide a bridge provided with the above-described bottom plate and a method for constructing the bridge.
The objects and features of the present invention will become more apparent from the preferred embodiments described below.

  According to an aspect of the present invention, there is provided a reinforced concrete slab that is divided and mounted on a bridge mold in a bridge axis direction and a direction perpendicular to the bridge axis, and both ends are placed on the mold and integrated with the mold. A precast prestressed reinforced concrete bottom plate is disclosed in which at least one sheath pipe into which a PC strand is inserted from the outside in a direction perpendicular to the bridge axis is embedded.

  Preferably, the sheath pipe can be extended along a position that cancels the tensile stress and the compressive stress applied to the slab.

  According to another aspect of the present invention, a plurality of molds extending in the direction of the bridge axis are fixed on the pier in parallel with the direction perpendicular to the bridge axis, and both ends are placed on the mold adjacent to the direction perpendicular to the bridge axis. The bottom plate is a reinforced concrete slab integrated with a mold, and at least one sheath pipe into which a PC strand is inserted from the outside in a direction perpendicular to the bridge axis in the slab. In the space between the bottom plates that are embedded and arranged in a form that resists positive and negative moments, the bottom plates are interconnected using reinforcing bars, and the embedded sheath pipe communicates throughout the direction perpendicular to the bridge axis. Precast bottom in which concrete is placed in this space, a PC strand is inserted into the sheath pipe and pulled and fixed, and protective walls are provided on the bottom plates at both ends in the direction perpendicular to the bridge axis Bridge equipped with is disclosed.

  Preferably, the bottom plates at both end portions are constructed by concrete placement on site.

  According to another aspect of the present invention, in a state where a plurality of molds extending in the bridge axis direction are fixed on the pier in parallel to the bridge axis perpendicular direction, both ends of the mold adjacent to the bridge axis perpendicular direction are arranged at both ends. Placing a plurality of bottom plates such that the bottom plate is a reinforced concrete slab integrated with a mold, and at least the PC strand is inserted into the slab from the outside in a direction perpendicular to the bridge axis. One or more sheath pipes are embedded in a form that resists positive and negative moments; the bottom plates are joined together using reinforcing bars in the space between the arranged bottom plates, and the embedded sheath pipes are in the direction of the bridge axis intuition. A pre-comprising comprising: connecting in communication throughout; placing concrete in space; and inserting and pulling a PC strand into the sheath pipe to fix Method of constructing bridges with a strike bottom plate is disclosed.

  Preferably, the bottom plate at both end portions is formed by being cast together at the time of placing the concrete in a direction perpendicular to the bridge axis, and may further include providing a protective wall on the bottom plate at both end portions.

As described above, the present invention has various advantages.
First, even when the bridge width is very large, the size of the bottom plate to be installed can be set as appropriate, so that it is easy to transport and handle on site.
In addition, since the sheath pipe embedded in the direction perpendicular to the bridge axis is extended along a position where the tensile stress and the compressive stress applied to the bottom plate are offset, it can efficiently cope with the tensile stress and the compressive stress. That is, it is possible to efficiently deal with positive moments and negative moments.
Furthermore, when the mold and the bottom plate are joined, since they are simply joined by placing concrete, the workability is excellent and economical.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a perspective view showing a precast prestressed reinforced concrete bottom plate according to an embodiment of the present invention.
The bottom plate 200 is composed of a reinforced concrete slab 201 embedded so that the reinforcing bar 202 is exposed from the side surface. The bottom plate 200 is separately mounted on the bridge mold in the bridge axis direction and the bridge axis perpendicular direction, and is integrated with the mold.
In the reinforced concrete slab 201, at least one sheath pipe 204 is embedded in a direction perpendicular to the bridge axis, and a PC strand is inserted from the outside.
Preferably, the sheath pipe 204 can be extended along a position that cancels the tensile stress and the compressive stress applied to the reinforced concrete slab 201. Of course, it can also be extended in a straight line in the reinforced concrete slab 201 in the horizontal direction.

FIG. 2 is a perspective view schematically showing a bridge constructed using the bottom plate of the present invention, and FIGS. 3 and 4 are sectional views taken along lines III-III and IV-IV in FIG. 2, respectively.
A large number of molds 100 extending in the direction of the bridge axis are fixed on the pier 1 in parallel to the direction perpendicular to the bridge axis, and adjacent molds 100 are connected to each other in the direction perpendicular to the bridge axis (indicated by arrow A in FIG. 2). Girder 150 is provided at regular intervals in the bridge axis direction.
The bottom plate 200 is divided into a bridge axis direction and a bridge axis perpendicular direction, and is mounted on the mold 100. Both ends of the bottom plate 200 in the bridge axis perpendicular direction are placed on the adjacent mold 100, respectively.
A casting bottom plate 250 made by placing concrete on the outside is extended from a bottom plate 200 placed on the mold 100 located at both ends, and a protective wall 300 is provided on the casting bottom plate 250. The placement bottom plate 250 is provided at the time of construction on the site, and a precast protective wall manufactured in advance can be used as the protective wall.

Referring to FIGS. 3 and 4, the reinforcing bars 202 protruding from the side surfaces of the bottom plates 200 between the adjacent bottom plates 200 after being placed on the mold 100 are coupled to each other in an appropriate manner, and are externally exposed in a direction perpendicular to the bridge axis. The exposed sheath pipes 204 are connected by a coupler 206.
Concrete 240 is placed in the space between adjacent bottom plates 200 to integrate the entire bottom plate 200.

Below, the construction method of a bridge with the above structures is demonstrated.
After a large number of molds 100 are fixed on the pier 1, precast prestressed reinforced concrete bottom plates 200 according to the present invention are arranged in a direction perpendicular to the bridge axis and in the bridge axis direction.
As described above, the precast prestressed reinforced concrete bottom plate 200 is arranged such that certain portions are placed on the mold 100 at both ends in the direction perpendicular to the bridge axis.
After the bottom plates 200 are arranged, the adjacent bottom plates 200 are joined using the reinforcing bars 202 protruding from the side surfaces of the bottom plates 200. At this time, although not shown, the reinforcing bars protruding upward from the mold 100 can also be coupled together. The sheath pipe 204 exposed between the bottom plates 200 adjacent in the direction perpendicular to the bridge axis is communicated using a coupler 206.

On the other hand, a mold frame for the casting bottom plate 250 (cantilever portion bottom plate) is provided, and an extension sheath pipe 207 to be connected to the sheath pipe 204 of the bottom plate 200 at both end portions is embedded in the mold frame in advance.
Thereafter, concrete 240 is placed in the space between the bottom plates 200 and in the mold.
After curing the concrete, a PC strand (not shown) is inserted into one of the extension sheath pipes 207 exposed to the outside and protruded into the other extension sheath pipe 207, and then the PC strand is pulled and fixed to fix the ends. It fixes to the outer side of the casting bottom board 250 of both sides using the board 210. FIG. Preferably, a groove is formed on the outer side surface of the bottom plate 250 on both sides, and the end fixing plate 210 is positioned in the groove and then filled with epoxy to protect it from corrosion.

On the other hand, the fixing of the PC strand can be performed before the concrete is placed.
Thereafter, the protective wall 300 is provided on the placement bottom plate 250, and the bridge is completed by packaging on the surface made of the bottom plate 200 and the placed concrete 240.

On the other hand, when the precast bottom plate is used instead of forming the casting bottom plate 250, the process of providing a mold for the casting bottom plate 250 can be omitted.
Although the preferred embodiments of the present invention have been described above, various changes and modifications can be made without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the above-described embodiment, but should be determined by the appended claims.

It is a perspective view which shows the precast prestressed reinforced concrete bottom board by one Example of this invention. It is a perspective view which shows roughly the bridge constructed using the baseplate of this invention. It is sectional drawing which follows III-III of FIG. It is sectional drawing which follows IV-IV of FIG.

Explanation of symbols

100 mold 200 bottom plate (precast prestressed reinforced concrete bottom plate)
DESCRIPTION OF SYMBOLS 201 Reinforced concrete slab 202 Reinforcement 204 Sheath pipe 206 Coupler 207 Extension sheath pipe 240 Concrete 250 Placing bottom plate 300 Protective wall

Claims (6)

  A reinforced concrete slab that is split and mounted on a bridge mold in a direction perpendicular to the bridge axis and a direction perpendicular to the bridge axis, both ends being placed on the mold and integrated with the mold, and in the direction perpendicular to the bridge axis in the slab A precast prestressed reinforced concrete bottom plate, wherein at least one sheath pipe into which a PC strand is inserted from the outside is embedded.   The precast prestressed reinforced concrete bottom plate according to claim 1, wherein the sheath pipe is extended along a position that cancels a tensile stress and a compressive stress applied to the slab. A plurality of molds extending in the direction of the bridge axis are fixed on the pier in parallel to the direction perpendicular to the bridge axis,
A plurality of bottom plates are arranged so that both ends are placed on a mold adjacent to the direction perpendicular to the bridge axis,
The bottom plate is a reinforced concrete slab integrated with the mold, and at least one sheath pipe into which a PC strand is inserted from the outside in a direction perpendicular to the bridge axis in the slab has a positive moment and a negative moment. Buried in the form of resistance,
In the space between the arranged bottom plates, the bottom plates are interconnected using reinforcing bars, and the embedded sheath pipes are connected so as to communicate with each other in the direction perpendicular to the bridge axis,
A precast bottom plate, wherein concrete is placed in the space, a PC strand is inserted into the sheath pipe and pulled and fixed, and a protective wall is provided on the bottom plate at both end portions in a direction perpendicular to the bridge axis. Provided bridge.   The bridge provided with the precast bottom plate according to claim 3, wherein the bottom plate of the both end portions is constructed by concrete placement on site. In a state where a plurality of molds extending in the bridge axis direction are fixed in parallel to the bridge axis perpendicular direction on the pier, a plurality of molds are placed so that both ends are placed on the mold adjacent to the bridge axis perpendicular direction. Disposing a bottom plate, wherein the bottom plate is a reinforced concrete slab integrated with the mold, and at least one sheath pipe into which a PC strand is inserted from the outside in a direction perpendicular to the bridge axis in the slab. Embedded in a form that resists positive and negative moments;
In the space between the arranged bottom plates, the bottom plates are interconnected using reinforcing bars, and the embedded sheath pipes are connected so as to communicate with each other in the direction perpendicular to the bridge axis;
Placing concrete in the space; and
A method of constructing a bridge with a precast bottom plate, comprising the step of inserting a PC strand into the sheath pipe and pulling and fixing the strand. 6. The method according to claim 5, further comprising the step of forming a bottom plate on both side ends in the direction perpendicular to the bridge axis, and forming a protective wall on the bottom plate on both side ends. The construction method of the bridge provided with the precast baseplate as described in 2.

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