CN100482892C - Lower chord opening beam type corrugated steel web combination beam - Google Patents

Abstract

The lower chord open truss type corrugated steel web composite beam belongs to the bridge support component. The lower chord open truss type corrugated steel web composite beam is composed of an upper flange concrete slab, a corrugated steel web and a lower chord open truss rectangular steel pipe concrete member. Compared with the combined section of the steel truss web, the present invention adopts the corrugated steel web with higher shear strength instead of the steel web, which has a high shear bearing capacity. The lower chord of the open truss is composed of two rectangular steel pipes placed in parallel, concrete poured inside, horizontal supports between the rectangular steel pipes, and diagonal braces. The lower chord adopts this kind of steel tube concrete member, which can also overcome the problems of the lower flange concrete slab in the traditional corrugated steel web box girder and steel truss web combined section, which requires a large amount of construction work such as scaffolding, formwork, and concrete pouring. It can effectively improve the crack resistance of the structure, avoid the exposure of cracks, etc., and the durability of the structure can be significantly improved. Its lower chord is an open structure supported and connected, with simple structure and quick and convenient construction.

Description

Bottom Chord Open Truss Type Corrugated Steel Web Composite Beam

technical field

The invention relates to a lower chord open truss type corrugated steel web composite beam applicable to railway bridges and highway bridges, belonging to the technical field of bridge structures.

Background technique

The traditional steel truss web composite section is developed from the concrete box section, which uses steel truss instead of the concrete web of the box section, thus forming a concrete slab consisting of upper flange, steel truss and lower flange concrete The structural system of the joint stress of the plates is shown in Figure 1. When steel trusses are used for the webs of this type of structure, in order to avoid buckling of the steel trusses under compression, it is often necessary to pour concrete into the compression trusses, and sometimes it is necessary to apply prestress to the tension chords in order to reduce the level of tensile stress. A lot of work. At the same time, the composite section of the steel truss web is similar to the traditional corrugated steel web box girder (see Figure 2). The pouring of the lower flange concrete slab requires on-site erection of scaffolding and support formwork, which involves on-site workload and construction difficulties. Big and other issues. On the other hand, the concrete floor is prone to cracking under the action of positive bending moments, and the cracks will reduce the bearing capacity, stiffness and durability of the structure.

Contents of the invention

The purpose of the present invention is to significantly reduce the construction workload of the composite box girder pouring concrete and setting up scaffolding, supporting formwork, etc., and propose a lower chord open truss corrugated steel that can improve the structural bearing capacity, stiffness and crack resistance Web composite beam.

Technical scheme of the present invention is as follows:

A lower chord open truss-type corrugated steel web composite beam, characterized in that: the composite beam is composed of an upper flange concrete slab, a corrugated steel web and a lower chord rectangular steel tube concrete member, and the lower chord rectangular steel tube concrete member adopts open Open truss structure, the open truss structure is composed of two rectangular steel pipes placed in parallel, concrete poured inside, and horizontal supports and diagonal braces arranged between the two rectangular steel pipes; In the steel pipe, holes are reserved for tensioning and prestressing tendons.

The technical feature of the present invention is that the corbel A and the corbel B are welded on the inside of the rectangular steel pipe to connect the horizontal support and the diagonal brace between the two rectangular steel pipes.

Another technical feature of the present invention is: reserve concrete pouring holes on the upper surface of the rectangular steel pipe.

Compared with the prior art, the present invention has the following advantages and outstanding effects: ①Compared with the combined section of the steel truss web, the corrugated steel web with higher shear strength is used instead of the steel web, which has high shear resistance Carrying capacity. ②The lower chord is made of concrete filled steel tube, which can overcome the problem that the pouring of the lower flange concrete slab in the combined section of the traditional corrugated steel web box girder and steel truss web requires a large amount of construction work such as erecting scaffolding and formwork. Due to the use of steel pipe concrete, it can also effectively improve the crack resistance of the structure, avoid crack exposure, etc., and the durability of the structure can be significantly improved. ③The structure adopts the lower chord open truss type, and the rectangular steel pipes are only connected by supports. ④ The lower chord horizontal support and diagonal brace of the structure can also provide support for the pouring of the upper flange concrete slab, which reduces the workload of formwork engineering and concrete wet work and the formwork support process, and has a high degree of industrialization. The steel structure part is mainly prefabricated in the factory, and the quality is easy to guarantee.

Description of drawings

Figure 1 is a schematic diagram of a traditional steel truss web composite section box girder.

Figure 2 is a schematic diagram of a traditional corrugated steel web box girder.

Figure 3 is a schematic diagram of the lower chord open truss type corrugated steel web composite beam.

Figure 4 is a schematic diagram of the construction stage of the lower chord open truss type corrugated steel web composite beam (when the upper flange concrete slab is not poured).

Figure 5 is a schematic diagram of the structure of the lower chord open truss type corrugated steel web composite beam.

In the figure: 1—concrete slab of upper flange; 2—steel truss; 3—concrete slab of lower flange; 4—corrugated steel web; 5—steel plate; 6—bolt; 7—rectangular steel pipe; A; 9—corbel B; 10—horizontal support; 11—diagonal brace; 12—temporary tie bar; 13—concrete pouring hole; 14—prestressed tendon tensioning channel; 15—concrete.

Detailed ways

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

The invention provides a lower chord open truss type corrugated steel web composite beam that can greatly reduce the construction workload of the composite box girder for pouring concrete, erecting scaffolding, supporting formwork, etc., and can improve the structural bearing capacity, stiffness and crack resistance . As shown in Figures 3 to 5, the composite beam is composed of an upper flange concrete slab 1, a corrugated steel web 4, and a lower chord rectangular concrete-filled steel tube member. The lower chord rectangular steel tube concrete member adopts an open truss structure. The structure is composed of two rectangular steel pipes 7 arranged in parallel and the concrete 15 poured inside them, as well as the horizontal support 10 and the diagonal brace 11 arranged between the two rectangular steel pipes 7; The corbel A8 and corbel B9 are used to connect the horizontal support 10 and the diagonal brace 11 between the rectangular steel pipes, and in the rectangular steel pipe 7, it is necessary to reserve the holes 14 for the tensioned prestressed steel tendons, and the upper surface of the steel pipe is separated by a certain distance. Concrete filling holes 13 are reserved.

Construction procedure of the present invention is:

The lower chord open truss type corrugated steel web composite beam of the present invention is composed of three parts: steel structure joint (welding), lower chord steel pipe concrete (including the connection of support) and upper flange concrete slab pouring. As shown in Figures 4 to 5, the corrugated steel web 4 is firmly welded to the steel plate 5 and the rectangular steel pipe 7 in the factory, and the shear connector studs 6 are welded on the steel plate 5, and are placed at regular distances inside the rectangular steel pipe 7. The corbel A8 and corbel B9 are welded, and concrete pouring holes 13 are reserved at regular intervals on the upper surface of the rectangular steel pipe 7 . Transport each steel member to the construction site, carry out the positioning of the steel structure, connect the two steel members through the corbel A8 and the corbel B9 with the horizontal support 10 and the diagonal brace 11 (such as I-beam or angle steel, etc.), At the same time, its upper flange is also connected by temporary tie rods 12. After forming a stable structure, a prestressed tendon tension channel 14 is reserved in the rectangular steel pipe 7, and concrete 15 is injected into the rectangular steel pipe 7 through the concrete pouring hole 13. After the concrete 15 reaches a certain strength, the formwork of the upper flange concrete slab 1 is supported, the steel bars are bound and the concrete is poured. During the construction process of the lower chord concrete-filled steel pipe, when the structure bears the construction load and the deformation does not meet the deformation requirements, temporary supports should be set at a certain distance at the bottom of the steel pipe according to the calculation and analysis.

Claims (3)

1. A lower chord open truss type corrugated steel web composite beam is characterized in that: the composite beam is composed of an upper flange concrete slab (1), a corrugated steel web (4) and a lower chord rectangular steel tube concrete member. The lower chord rectangular concrete-filled steel tube member adopts an open truss structure, which is composed of two parallel rectangular steel pipes (7) and internal poured concrete (15), and is arranged on the two rectangular steel pipes ( 7) The horizontal support (10) and the diagonal brace (11) between are composed; the prestressed tendon tension beam channel (14) is reserved in the rectangular steel pipe (7). 2. A lower chord open truss type corrugated steel web composite beam according to claim 1, characterized in that: the corbel A (8) and the corbel B (9) are welded on the inner side of the rectangular steel pipe (7) ), used to connect horizontal supports and diagonal braces between two rectangular steel pipes. 3. A lower chord open truss type corrugated steel web composite beam according to claim 1, characterized in that: a concrete pouring hole (13) is reserved on the upper surface of the rectangular steel pipe (7).

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