CN112832116A

CN112832116A - A plate-truss composite main beam suitable for large-span cable-stayed bridges in mountainous areas

Info

Publication number: CN112832116A
Application number: CN202110166174.5A
Authority: CN
Inventors: 田波; 周霆; 牟廷敏; 梁健; 谭邦明; 康玲
Original assignee: Sichuan Department of Transportation Highway Planning Prospecting and Design Research Institute
Current assignee: Sichuan Department of Transportation Highway Planning Prospecting and Design Research Institute
Priority date: 2021-02-07
Filing date: 2021-02-07
Publication date: 2021-05-25

Abstract

The utility model provides a be fit for mountain area stride cable-stay bridge's board purlin combination girder to effectively improve the efficiency of construction, overcome the easy technological problem who ftractures of steel bridge deck system bridge deck pavement, avoid the fatigue problem of traditional steel bridge panel moreover. The main girder is composed of a steel truss girder bridge deck structure, the bridge deck structure is a steel-concrete combined bridge deck plate composed of a steel bottom plate and cast-in-place steel fiber concrete, the steel bottom plate is arranged between an adjacent cross beam, an adjacent longitudinal beam, an upper chord of the main truss and the adjacent longitudinal beam, bearings are arranged at the welding connection positions of the steel bottom plate and the upper chord of the main truss, the longitudinal beam and the cross beam, and the cast-in-place steel fiber concrete is connected with the steel bottom plate, the upper chord of the main truss, the longitudinal beam and the cross beam into a whole through shear keys.

Description

Plate-truss combined main beam suitable for large-span cable-stayed bridge in mountainous area

Technical Field

The invention relates to bridge engineering, in particular to a plate girder combined main beam suitable for a large-span cable-stayed bridge in a mountainous area.

Background

When the cable-stayed bridge with the ultra-large span is built in a mountain area, a steel main beam is generally selected due to the structural stress requirement. Considering that the traffic and transportation conditions in mountainous areas lag behind and the transportation of large sections is difficult, the main beam is mostly in a steel truss beam form. The bridge deck is made of orthogonal deformed steel bridge deck or precast concrete bridge deck. The orthotropic bridge deck has high requirements on processing and manufacturing processes, fatigue cracks are easy to appear, the combination with bridge deck pavement is poor, and the bridge deck pavement is easy to cause diseases in the operation period. The prefabricated bridge deck is hoisted after being prefabricated, and finally is connected into an integral bridge deck through cast-in-place wet joints, so that the construction procedures are multiple, the requirements on the prefabrication and installation precision are high, the integrity is poor, and the joints after being poured are easy to crack.

Disclosure of Invention

The invention aims to provide a plate girder and truss combined main beam suitable for a large-span cable-stayed bridge in a mountainous area, so that the construction efficiency is effectively improved, the technical problem that a steel bridge deck system is easy to crack in bridge deck pavement is solved, and the fatigue problem of a traditional steel bridge deck is avoided.

The technical scheme adopted by the invention for solving the technical problems is as follows:

the invention relates to a plate girder combined main beam suitable for a large-span cable-stayed bridge in a mountainous area, which is formed by a steel girder bridge deck structure and is characterized in that: the bridge deck structure is a steel-concrete combined bridge deck plate composed of a steel bottom plate and cast-in-place steel fiber concrete, the steel bottom plate is arranged between adjacent cross beams, adjacent longitudinal beams, an upper chord of a main truss and the adjacent longitudinal beams, bearings are arranged at the welding joints of the steel bottom plate and the upper chord of the main truss, the longitudinal beams and the cross beams, and the cast-in-place steel fiber concrete is connected with the steel bottom plate, the upper chord of the main truss, the longitudinal beams and the cross beams into a whole through shear keys.

The invention has the advantages that the steel-concrete plate girder combined main girder structure is adopted to thoroughly solve the fatigue problem of the steel bridge deck and the problem of poor pavement and bonding of the steel bridge deck, thereby effectively preventing the steel bridge deck from cracking and pavement damage; compared with the traditional composite beam adopting the precast concrete deck slab, the steel-concrete plate girder composite main beam takes the steel bottom plate as a construction template, and the cast-in-place steel fiber concrete forms a whole, so that the construction efficiency is improved, and the defects of high construction precision requirement and complex process of the precast deck slab are overcome; the main beam is an ideal main beam form for the large-span cable-stayed bridge in the mountainous area under the construction conditions of narrow construction site and difficult transportation of large sections.

Drawings

The specification includes the following five figures:

FIG. 1 is a cross-sectional view of a plate girder combined main beam suitable for a large-span cable-stayed bridge in a mountainous area;

FIG. 2 is an enlarged view of portion A of FIG. 1;

FIG. 3 is a schematic structural diagram (between cross beams) of a bridge deck in a plate girder combined main beam suitable for a large-span cable-stayed bridge in a mountainous area;

fig. 4 is a schematic structural view (on a cross beam) of a bridge deck in a plate-truss combined main beam suitable for a large-span cable-stayed bridge in a mountainous area.

Fig. 5 is a sectional view taken along line B-B in fig. 4.

The component names and corresponding labels are shown in the figure: the main truss comprises main truss upper chords 11, longitudinal girders 12, cross girders 13, a steel bottom plate 21, cast-in-place steel fiber concrete 22, PBL shear keys 23 and stud shear keys 24.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

Referring to fig. 1 to 5, the plate girder combined main girder suitable for the large-span cable-stayed bridge in the mountainous area comprises a steel girder and a bridge deck structure, wherein the upper part of the steel girder comprises a main girder upper chord 11, longitudinal girders 12 arranged at intervals in the transverse bridge direction and transverse girders 13 arranged at intervals in the bridge direction. Referring to fig. 1 and 2, the bridge deck structure is a steel-concrete combined bridge deck plate formed by a steel bottom plate 21 and cast-in-place steel fiber concrete 22, the steel bottom plate 21 is arranged between adjacent cross beams 13, adjacent longitudinal beams 12, a main truss upper chord 11 and adjacent longitudinal beams 12, supports are arranged at the welding joints of the steel bottom plate 21 and the main truss upper chord 11, the longitudinal beams 12 and the cross beams 13, and the cast-in-place steel fiber concrete 22 is connected with the steel bottom plate 21, the main truss upper chord 11, the longitudinal beams 12 and the cross beams 13 into a whole through shear keys.

The invention designs the bridge deck into a combined structure of the steel bottom plate and the concrete bridge deck, and combines the steel bottom plate and the concrete bridge deck with the main truss girder through the shear keys to form a plate truss combination system, and the plate truss combination system is stressed together, thereby not only overcoming the problem that the bridge deck pavement of the steel bridge deck system is easy to crack, but also avoiding the fatigue problem of the traditional steel bridge deck. During construction, the bridge deck steel bottom plate and the steel truss girder segments are assembled together, after the bridge deck steel bottom plate and the steel truss girder segments are installed in place, the steel bottom plate is used as a steel fiber concrete pouring template, and a combined beam integral bridge floor is formed after the steel fiber concrete is poured, so that the structural form of the traditional precast concrete slab is simplified, the integrity is good, the construction is rapid, and the difficult problems that the construction site is narrow and small and the precast site is difficult to lay under the condition of a mountain area are solved.

Referring to fig. 3 to 5, the shear key comprises PBL shear keys 23 arranged on the steel bottom plate 21 at intervals in the transverse bridge direction, and the PBL shear keys 23 extend along the bridge direction and are welded with the steel bottom plate 21. The shear key further comprises stud shear keys 24 which are arranged at intervals in the outer bearing transverse bridge direction and the bridge direction, and the stud shear keys 24 are welded with the upper chord 11, the longitudinal beam 12 or the cross beam 13 of the main truss.

The above description is only used to illustrate some principles of the plate girder combined main girder of the cable-stayed bridge suitable for mountain spans, and the present invention is not limited to the specific structure and the application range shown and described, so all the corresponding modifications and equivalents that may be utilized belong to the patent scope of the present invention.

Claims

1. A plate-truss composite main girder suitable for large-span cable-stayed bridges in mountainous areas, the main girder is composed of a steel truss girder and a bridge deck structure, and the upper part of the steel truss girder comprises an upper chord (11) of the main truss, and longitudinal beams arranged at intervals in the transverse bridge direction (12) and a beam (13) arranged at intervals along the bridge direction, characterized in that: the bridge deck structure is a steel-concrete composite bridge deck composed of a steel base plate (21) and a cast-in-place steel fiber concrete (22), and the steel base plate is composed of a steel-concrete composite bridge deck. (21) is arranged between the adjacent beams (13), the adjacent longitudinal beams (12), the main truss upper chord (11) and the adjacent longitudinal beams (12), the steel bottom plate (21) and the main truss upper chord (11) ), longitudinal beam (12) and cross beam (13) welded joints are provided with supports, and the cast-in-place steel fiber reinforced concrete (22) is connected to the steel base plate (21), the main truss upper chord (11), the longitudinal beam (12) through shear keys ) and the beam (13) are connected as a whole.

2. A plate-truss composite main girder suitable for a large-span cable-stayed bridge in mountainous areas as claimed in claim 1, wherein the shear key comprises a steel bottom plate (21) plate surface that is arranged at intervals in the transverse bridge direction. PBL shear key (23), the PBL shear key (23) extends along the bridge direction and is welded with the steel base plate (21).

3. The plate-truss composite main girder suitable for large-span cable-stayed bridges in mountainous areas as claimed in claim 2, characterized in that: the shear key also includes spacers arranged at intervals in the transverse bridge direction and along the bridge direction outside the support. The stud shear key (24) is welded with the upper chord (11), longitudinal beam (12) or cross beam (13) of the main truss.