JP2000212916A - Steel-concrete-composite railway bridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the economic efficiency by reducing the manufacturing man-days and massproducing girders having the same size while using relatively costless round steel pipes which can be easily obtained in the market, in a steel-concrete-composite railway bridge. SOLUTION: In a steel-concrete-composite railway bridge in which a steel girder and a concrete floor slab supported by the substructure of the viaduct are integrally combined, a round steel pipe 1 is used as the steel girder. The round steel pipe 1 is arranged right under the track 5 laid on the concrete floor slab to directly receive the load from the track 5 by the single round steel pipe 1. Single track structures in which one round steel pipe 1 for a track is used for the main girder are parallelly laid and repective tracks 5 are supported by these respective round steel pipes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel-concrete composite railway bridge in which a concrete slab is integrated with an upper part of a steel girder and supported by a substructure such as a pier or a pillar. Suitable when the length is continuous over multiple diameters.

[0002]

2. Description of the Related Art Conventionally, an elevated section of a railway bridge, except a section that must be a long span due to crossing properties such as a river,
The concrete frame structure with short span is mainly used mainly from the viewpoint of economy.

[0003] In the case of a steel railway bridge, there are problems of noise caused by train running, problems of maintenance and management, and problems of cost. Development and practical use of a railway bridge having a composite structure in which a steel girder and a concrete floor slab are integrated. However, it has been considered that small and medium-sized bridges are difficult to adopt because they are less economical than concrete railway bridges.

On the other hand, Hosaka Tetsuya: "A trial of steel railway bridge pursuing economic efficiency", 1st Symposium on Steel Structures and Bridges (August 1998), published by Japan Society of Civil Engineers,
From page 89 to page 97, regarding railway bridges, the dead load is reduced by reducing as much as possible the concrete in the tensile region that does not contribute as a structure to the conventional welded H-beam embedded girder composite structure. A multi-T-shaped SRC girder pursuing economy by pursuing it, as shown in FIG. 3, a composite girder filled with steel pipe filled with concrete etc. in a commercially available round steel pipe, other intermittent composite girder, beach Unpainted 4-span continuous double composite girder for the district is introduced.

[0005]

As described above, steel girders are generally expensive during short spans, and are likely to be affected by vibrations in urban areas. Therefore, the possibility of selecting steel girders at the comparative design stage was low.

However, steel girders are superior in strength and stability and lighter in weight than concrete structures such as reinforced concrete and prestressed concrete, so that they are advantageous in terms of workability and economical efficiency. If so, it can be a reasonable structure.

That is, a lightweight steel girder is excellent in earthquake resistance and can contribute to simplification of a substructure shape. In addition, vibrations caused by train running and the like can be dealt with by comprehensive vibration damping measures such as sleepers, tracks and in-girder measures.

The present invention has been made in view of the above-mentioned background. For a railway bridge having a steel-concrete composite structure, a relatively inexpensive round steel pipe having marketability is used, and the number of manufacturing steps is reduced. The purpose of the present invention is to provide a steel-concrete composite railway bridge that can reduce costs, for example, by reducing the size and mass-producing girders of the same size.

[0009]

A steel-concrete composite railway bridge according to claim 1 of the present application has a concrete floor slab integrated with an upper part of a steel girder and supported by a substructure at a predetermined span.
In a steel-concrete composite railway bridge with a railway track laid on a concrete slab, a round steel pipe was used as a steel girder.
This round steel pipe is arranged immediately below a track laid on a concrete floor slab, and a single round steel pipe is directly subjected to a load from the track.

[0010] The round steel pipe has a marketability, and it is possible to use a commercially available one or to easily mass produce it by an existing pipe manufacturing technique. Therefore, for example, when applied to a continuous girder of the same span length, cost reduction can be achieved by commercializing.

The term "predetermined span" referred to in the present application means a span length determined by design, and the span lengths do not necessarily have to be the same. However, in consideration of the effect of commercialization, it is effective to set the length of the span to about 18 m at maximum, including workability and transportability.

[0012] By arranging the round steel pipe immediately below the track on which it is laid, the train load traveling on the track is efficiently transmitted, and the bending moment generated at the floor slab can be reduced. Further, in the case of a round steel pipe, it is easy to cope with the diameter of the steel pipe between railroad gauges. Further, in a short span railway bridge, since the sectional force is relatively small, the steel pipe diameter can be reduced, and the stiffener can be omitted depending on the relationship between the diameter and the plate thickness.

According to a second aspect of the present invention, in the steel-concrete composite railway bridge according to the first aspect, a girder having a single-line structure constituted by disposing a single round steel pipe as a steel girder immediately below a single track is provided. In this case, a plurality of girder portions having a double-track structure are arranged in parallel, and these are supported by a substructure.

That is, one round steel pipe is used as a main girder for one railroad track, a single-line structure is used as a bridge structure, and a double-line structure is formed by paralleling a single-line structure. Since each track is assigned to each round steel pipe, design is easy, and a simple structure in which stiffeners and the like are omitted is possible, so that workability is good.

A third aspect of the present invention is a steel-concrete composite railway bridge according to the first or second aspect, wherein the case where a dowel is provided on the upper surface of the round steel pipe is limited. As the dowel, for example, there is a stud dowel by welding, but the type is not particularly limited as long as it can synthesize a round steel pipe girder and a concrete floor slab.

A fourth aspect of the present invention is a steel-concrete composite railway bridge according to the first, second or third aspect, wherein the span is 18 m or less. In the production of round steel pipe,
From the viewpoint of construction and transportation, it is desirable that the distance between the supports for supporting the round dies be within a maximum of about 18 m. Further, if the span length is made continuous, the cost can be further reduced.

[0017]

FIG. 1 shows the structure of a joint between a steel girder and a concrete floor slab using a round steel pipe 1 in an embodiment of a steel-concrete composite railway bridge of the present invention. .

In the example shown in the figure, a composite steel girder is formed by casting concrete 3 using a round steel pipe 1 and a steel sheet 2 joined to the upper side of the round steel pipe 1 and bent upward. The railroad track 5 for railroad is laid directly above it.

In the figure, reference numeral 4 denotes a welding wire mesh for reinforcing the concrete 3, and reference numeral 5 a denotes a rail constituting the track 5. This example is particularly applicable to one railway track.
The round steel pipe 1 is used as a main girder, the bridge structure is a single-line structure, and the overall structure is a double-line structure in which the single-line structures are arranged in parallel.

That is, for example, as shown in FIG.
The round steel pipes 1 respectively corresponding to one track supported by the rails are connected to each other by the horizontal connecting members 8 to form a three-dimensional rigid frame structure, thereby forming a railway bridge having a double track structure.

In addition, the substructure is not particularly limited, and there is a structure in which steel pipes or steel pipe-filled concrete pillars are juxtaposed, and these are connected by cross beams.

[0022]

According to the present invention, in a steel-concrete composite railway bridge, a round steel pipe as a steel girder is arranged immediately below a track laid on a concrete floor slab, and a load from the track is applied to a single round steel pipe. , The train load running on the track can be transmitted rationally and efficiently.

Since the concrete slab portion receives the girder action as a composite girder and does not directly receive the train load as the slab action, the arrangement of reinforcing bars can be simplified, and the efficiency of on-site construction can be improved. In addition, the on-site construction work period can be shortened by omitting the temporary support members and joining bolts of steel materials on site.

[0024] In the short span railway bridge to which the present invention is mainly applied, since the sectional force is relatively small, the diameter of the steel pipe can be reduced, and the stiffener can be omitted due to the relationship between the diameter and the plate thickness. In the invention according to claim 2, one round steel pipe is used as a main girder for one railroad track, the bridge structure is a single-line structure, and the overall structure is a double-line structure in which the single-line structure is arranged in parallel. Since each round steel pipe handles each track, design is easy, and a simple structure in which stiffeners and the like are omitted is possible, so that workability is good.

According to the third aspect of the present invention, the applicable span length is set to 18 m or less, which is desirable in terms of manufacturing, construction, and transportation. Can be.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view showing a structure of a joint portion between a steel girder and a concrete floor slab using a round steel pipe according to an embodiment of the present invention.

FIG. 2 is a perspective view when a round steel pipe according to an embodiment of the present invention is arranged in parallel to form a double-track structure.

Fig. 3 shows the outline of the structure of a conventional railway bridge using a composite girder made of concrete-filled steel pipes. (A) is a perspective view, (b) is a cross-sectional view in the direction perpendicular to the bridge axis (left half is The cross section of the fulcrum portion, and the right half is the cross section of the fulcrum portion).

[Explanation of symbols]

1: round steel pipe, 2: side steel plate, 3: concrete, 4:
Welding wire mesh, 5 ... track, 5a ... rail, 6 ... bearing part, 7 ...
Pillar, 8 ... horizontal connecting material, 11 ... concrete filled steel pipe

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yukio Abe 4-5-33 Kitahama, Chuo-ku, Osaka-shi, Osaka Sumitomo Metal Industries, Ltd. F term (reference) 2D059 AA14 AA17

Claims (4)

[Claims] 1. A steel-concrete composite railway bridge in which a concrete slab is integrated with an upper part of a steel girder, supported by a substructure at a predetermined span, and a railway track is laid on the concrete slab. Using a round steel pipe, the round steel pipe is disposed directly below a track laid on the concrete floor slab, and a load from the track is directly received by a single round steel pipe. Steel concrete composite railway bridge. 2. A single wire girder composed of a single round steel pipe as a steel girder disposed immediately below a single track, and a plurality of girders of a double wire structure are arranged in parallel to form a girder of a double wire structure. The steel-concrete composite railway bridge according to claim 1, wherein the substructure is supported by a substructure. 3. The steel-concrete composite railway bridge according to claim 1, wherein a dowel is provided on an upper surface of the round steel pipe. 4. The steel-concrete composite railway bridge according to claim 1, wherein the span is 18 m or less.