JP2000248510A - Bar arrangement structure of box-shaped main girder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase efficiency in execution work, and to improve safety by respectively arranging plural lattice reinforcements preassembled in a lattice shape as reinforcing reinforcements in upper/lower flange parts and left/right springing-out parts. SOLUTION: Left/right webs 4 are arranged between both edge parts of upper/lower flange parts 2, 3 arranged above and below at a prescribed interval, and springing-out parts 5 are respectively projected in a cantilever shape in the edge part of the upper flange part 2 to constitute a box-shaped main girder 2. Lattice reinforcements 6 preassembled in a lattice shape on the ground as reinforcing reinforcements are respectively arranged in the upper/lower flange parts 2, 3 and the left/right springing-out parts 5. The lattice reinforcements 6 assembled in a lattice shape or plural reinforcements are also arranged in a lattice shape in the webs 4. Bar arrangement of the lattice reinforcements 6 can be extremely efficiently and safely performed by construction heavy machinery such as a crane, so that labor of bar arrangement work can be sharply reduced, and safe execution work can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to upper and lower flange portions which are vertically arranged at predetermined intervals, and left and right web portions and upper and lower flange portions which are respectively disposed on both sides of the upper and lower flange portions. The present invention relates to a reinforcing structure of a box-shaped main girder constructed having left and right protruding portions provided.

[0002]

2. Description of the Related Art A box-shaped main girder is known as a main girder for a viaduct or the like. The box-shaped main girder has a closed cross-sectional structure composed of upper and lower flange portions arranged vertically at predetermined intervals and left and right web portions arranged between both sides of the upper and lower flange portions, and the cross section is concentrated on the upper and lower flange portions. Is an efficient shape,
Be able to withstand large compressive forces due to bending moments,
The continuous girder has such characteristics that a large amount of reinforcing steel can be arranged, and that the torsional rigidity is large, so that the protruding part can protrude largely as a part of the sidewalk on both edges of the upper flange part. It is suitable for long bridges such as bridges and ramen bridges, and is also suitable for curved bridges.

[0003] In addition, as a construction method, besides a method of constructing the main girder at a time or one span at a time by a erection method using a fixed or movable shoring method, an overhanging erection method or an extrusion method for a continuous PC girder. Construction methods are known.

[0004]

However, it is necessary to arrange reinforcing bars one by one in any of the construction methods.
There were problems such as not only being forced to arrange reinforcement by skilled rebar workers, but also extremely poor workability.

[0005] In addition, since reinforcing bars of this type generally have a large diameter, a human accident may occur due to weather, excessive fatigue, and the like, and there is also a problem in safety. The present invention has been made to solve the above problems,
An object of the present invention is to provide a box-shaped main girder reinforcing structure in which reinforcement of reinforcing bars can be extremely efficiently and safely performed, and workability and safety can be greatly improved.

[0006]

As a means for solving the above problems, a reinforcing structure of a box-shaped main girder according to the present invention is characterized in that the upper and lower flange portions of the box-shaped main girder are bounced left and right. Lattice reinforcements assembled in a lattice shape in advance as reinforcement reinforcements are arranged on the stockings.

According to a second aspect of the present invention, in the box-shaped main girder reinforcing structure of the first aspect, a plurality of lattice reinforcing bars or a plurality of reinforcing bars previously assembled in a lattice shape as strong reinforcing bars on the left and right web portions are arranged one by one. Arrange them in a shape.

According to a third aspect of the present invention, in the reinforcing structure of the box-shaped main girder according to the first or second aspect, a plurality of tension members are continuously provided in the upper flange portion and the left and right projecting portions in a direction perpendicular to the axis of the main girder. Insert.

[0009]

1 to 3 show an embodiment of the present invention. A box-shaped main girder 1 comprises upper and lower flange portions 2, 3 which are arranged at predetermined intervals above and below and upper and lower flange portions 2, 3. Of the reinforced concrete (hereinafter referred to as "R") having left and right web portions 4 disposed between both edge portions thereof and a spring portion 5 respectively protruding in a cantilever manner at the edge portion of the upper flange portion 2.
C) structure or a prestressed concrete (hereinafter, referred to as “PC”) structure.

Particularly, in the case of a box-shaped main girder having a PC structure, a plurality of PC steel members (not shown) are provided on the upper and lower flange portions 2 and 3 and, if necessary, on the left and right web portions 4. A prestress is introduced in the axial direction of the box-shaped main girder 1 by continuously inserting the PC steel material in the axial direction and continuously inserting the PC steel material.

An upper flange portion 2 and a left and right spring portion 5 are provided.
, A plurality of PC steel materials are continuously inserted in the direction perpendicular to the axis of the box-shaped main girder 1, and the PC steel material is tensioned to introduce prestress in the direction perpendicular to the axis of the box-shaped main girder 1.

Further, in both the box-shaped main girder of the RC structure and the PC structure, the upper and lower flange portions 2 and 3 and the left and right protruding portion 5 are provided with lattice reinforcing bars 6 previously assembled in a lattice form on the ground as reinforcing reinforcing bars. Each bar is arranged.

The web 4 is provided with a reinforcing bar or a plurality of reinforcing bars pre-assembled in a grid shape as reinforcing reinforcing bars one by one in a grid shape. At that time, the reinforcing bars are doubled in principle in each case.

The lattice reinforcing bar 6 is formed by arranging a plurality of vertical reinforcing bars 6a continuous in the axial direction of the box-shaped main girder 1 and a plurality of horizontal reinforcing bars 6b continuous in the direction perpendicular to the axis of the box-shaped main girder 1 in a grid shape. It is formed in a plate shape.

A deformed reinforcing bar or a threaded reinforcing bar is mainly used for the vertical reinforcing bar 6a and the horizontal reinforcing bar 6b, and intersections of the vertical reinforcing bar 6a and the horizontal reinforcing bar 6b are integrally fixed by welding or the like. In addition, the diameter of the reinforcing bar of the vertical reinforcing bar 6a and the reinforcing bar pitch of the horizontal reinforcing bar 6b are set according to the design stress.

Further, the lattice reinforcing bars 6 arranged on the upper and lower flange portions 2 and 3, the left and right webs 4 and the rebounding portion 5 are connected to each other. In addition to the joints, the joints are connected by, for example, a collar crimp, a threes joint, or a screw joint. In addition, the joints of the reinforcing bars are provided so as to be appropriately shifted so as not to be concentrated at one place and disadvantageous in terms of stress.

Here, in the collar crimping, the ends of the rebars are inserted into a steel sleeve, and the steel sleeves are crushed from above, and the steel sleeves are strongly bite into the nodes of the rebar surface to connect the rebars. Is the way.

Further, the sleeve joint is a method in which an end of a reinforcing bar is inserted into a sleeve having a large number of irregularities inside, and the sleeve and the reinforcing bar are solidified with a filler such as resin mortar to connect the reinforcing bars. Further, the threaded joint is a method in which a male thread portion formed at an end of a reinforcing bar is connected with a long nut.

When arranging the reinforcing bars 6, the arranging of the reinforcing bars 6 is extremely efficiently performed by a heavy construction machine such as a crane. As described above, by arranging the lattice reinforcing bars 6 as reinforcing reinforcing bars of the box-shaped main girder 1, it is possible to perform the reinforcing arrangement work extremely efficiently and safely without any particular skill, and to perform the reinforcing arrangement work. Significant labor saving and safe construction can be achieved.

3 (a) and 3 (b) show another example of a box-shaped main girder. FIG. 3 (a) shows a multi-gear box-shaped main girder, and FIG. 3 (b) shows a multiple box-shaped main girder. In any of the above examples, for any box-shaped main girder, at least the upper and lower flanges 2 and 3 and the left and right protruding portions 5 are laid out in advance as grid reinforcing bars as reinforcing bars. Significant labor saving and safe construction can be achieved.

[0021]

The present invention has the above-described structure,
In particular, at least the upper and lower flanges and the left and right protrusions of the box-shaped main girder are provided with reinforcing bars that are pre-assembled in a grid shape as reinforcing bars, so this is far more than arranging reinforcing bars one by one. Significant labor saving and safe construction of muscle work can be achieved.

[Brief description of the drawings]

FIG. 1 shows a box-shaped main girder, (a) is a partial perspective view thereof,
(B) is a sectional view thereof.

FIG. 2A is a partial perspective view showing the arrangement of reinforcing bars of a box-shaped main girder, and FIG. 2B is a partial perspective view of a lattice reinforcing bar.

FIGS. 3A and 3B are cross-sectional views of a box-shaped main girder showing another example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Box main girder 2 Upper flange part 3 Lower flange part 4 Web part 5 Protruding part 6 Grid reinforcement

Claims (3)

[Claims] 1. Upper and lower flange portions arranged vertically at predetermined intervals, right and left web portions arranged on both sides of the upper and lower flange portions, and left and right bouncing portions projecting from both edges of the upper flange portion. In the reinforcing structure of the box-shaped main girder constructed to have each part, a plurality of lattice reinforcing bars previously assembled in a lattice shape as reinforcing reinforcing bars are arranged on the upper and lower flange parts and the left and right protruding parts. A bar-shaped main girder reinforcement structure. 2. A box-shaped main girder according to claim 1, wherein a plurality of lattice reinforcing bars or a plurality of reinforcing bars previously assembled in a lattice shape as reinforcing bars are arranged on the left and right web portions in a lattice shape. Reinforcement structure. 3. The box-shaped main girder according to claim 1, wherein a plurality of tendons are continuously inserted through the upper flange portion and the left and right projecting portions in a direction perpendicular to the axis of the main girder. Bar arrangement structure.