CN1676753A - Self-anchored cable-stayed-suspension collaborative bridge - Google Patents

Abstract

This invention relates to the design of big span bridge in the bridge construction. It combines the merits of cable stayed bridge and suspension bridge, and by using self-anchored architecture, it comes out to be a kind of design program of big span bridge. During the process of construction, when the kingpost of the cable stayed bridge has been consolidated, we fix the main cable's temporary anchor onto the steel frame made up of several abutment pier and lift the girder of the steel box in the middle. After the main girder is closed, the architecture changing should be finished to form permanent self-anchored architecture, and then adjust the strength of the cables of the whole bridge. This invention has great effects and merits of solving the problem of the design and construction of big span bridge. It also fully uses the material, saving big position holdings and decreasing the cost of the project. At the same time, the working time is reduced, decreasing the risk during the working process.

Description

Self-anchored cable-stayed-suspension collaborative bridge

technical field

The invention belongs to the technical field of construction engineering and relates to the design of bridges in bridge engineering, in particular to the design of long-span bridges.

Background technique

Currently, three types of bridges are commonly used in the design of long-span bridges:

One is the cable-stayed bridge scheme. The cable-stayed bridge with the largest span that has been built now is the Tatara Bridge in Japan, with a span of 890m. However, when the cantilever span of the cable-stayed bridge reaches about 500m during construction, its aerodynamic stability is really worrying. At the same time, its axial horizontal pressure will increase rapidly with the increase of the cantilever span. Buckling instability will occur near the tower.

Another bridge type scheme is the suspension bridge scheme. The suspension bridge with the largest span that has been built now is the Akashi Kaikyo Bridge in Japan, with a main span of 1991m. However, the amount of steel used for the main cable and girder of the suspension bridge is large, which increases the construction cost. At the same time, the long-span suspension bridges are all anchored in the ground, requiring huge anchorage, and their volume increases rapidly with the increase of the span. According to reports, the cost of a suspension bridge with a main span of 1000m is 16.7% higher than that of a cable-stayed bridge with the same span. In addition, aerodynamic stability is also a restrictive factor for the development of suspension bridges with large spans.

There is also a ground-anchored cable-stayed-suspension cooperative bridge. The first bridge of this type in the world, Guizhou Wujiang Bridge, has been built in China, with a main span of only 288m. Many domestic and foreign sea-crossing bridges, such as the Lingdingyang Bridge and the Bering Strait Bridge, have proposed this scheme. At present, the bridge type is mainly in the scheme design stage. The proposed schemes are all ground anchor systems, which require huge ground anchors, are difficult to construct, and cost high.

Contents of the invention

The purpose of this invention is to propose a kind of large-span bridge type design scheme.

The technical solution of the present invention is to first construct the cable-stayed bridge part, then hang the main cable, temporarily anchor the main cable on the frame formed by a plurality of side piers, then hoist the steel girder of the suspension bridge part, and complete the ground anchor system to the self Conversion of anchor systems.

The specific steps are:

1. After the cable tower and side hole piers are completed, the cantilever assembly of the concrete main girder of the cable-stayed bridge begins;

2. After the cantilever is assembled to the side hole, the main cable is suspended, and its two ends are respectively anchored on the anchor block at the outer end of the concrete beam, and the anchor block is pulled on the frame formed by multiple pier columns of the approach bridge with temporary anchor cables;

3. Use a cable crane to hoist the steel girders of each section of the mid-span;

4. After closing, remove the temporary anchor cables in batches, and the main cable is completely anchored at both ends of the main girder to become a self-anchored main cable, completing the system conversion from temporary ground anchor to self-anchor;

5. Complete the bridge deck pavement, railing construction, and adjust the cable force of the whole bridge to complete the bridge.

From this point of view, the two systems of cable-stayed bridge and suspension bridge exist separately in the construction process, and they cooperate with each other after the bridge is completed, and the bridge is a self-anchored system, so the bridge type is named "self-anchored cable-stayed-suspension bridge". Cable Collaboration Bridge".

Effect and benefit of the present invention are:

1. The use of self-anchoring system saves huge anchorage, not only reduces the cost, but also shortens the construction period;

2. The load of the cable-stayed bridge part is transmitted to the tower foundation through the bridge tower, unlike in the suspension bridge, this part of the load is transmitted to the tower foundation through the main cable, which reduces the diameter of the main cable and saves materials;

3. During the construction process, the cantilever of the cable-stayed bridge is shortened, and the range of the suspension bridge is also reduced after the completion of the bridge. Therefore, the aerodynamic stability during the construction process and after the completion of the bridge has been significantly improved, reducing the risk during the construction process ;

4. The part of the cable-stayed bridge is shortened, and the axial pressure at the root of the main beam near the tower is reduced. While ensuring the stability of the main beam, it can also reduce the area of the concrete main beam and reduce the project cost;

5. Concrete girders are used in the cable-stayed bridge section, while steel girders are used in the suspension bridge section to give full play to the material properties and greatly save the cost.

Description of drawings

Figure 1 is a schematic diagram of the temporary ground anchor of a self-anchored cable-stayed-suspension cooperative bridge.

In the picture: 1 main cable, 2 main girder, 3 suspender, 4 stay cable, 5 main tower, 6 side piers.

Figure 2 is a schematic diagram of the completion scheme of the self-anchored cable-stayed-suspension collaborative bridge.

In the figure: 1 main cable, 2 main girder, 3 suspender, 4 stay cable, 5 main tower, 7 anchor block.

Detailed ways

The best embodiments of the present invention will be described in detail below in conjunction with the technical solutions and accompanying drawings.

After the main girder of the cable-stayed bridge is assembled in place, the main cable is suspended, and the main cable is anchored on the anchor block at the end of the concrete beam, and is anchored on the frame structure composed of multiple pier columns of the approach bridge through the temporary anchor cable. The middle steel box girder is hoisted, and after the main girder is closed, the system conversion is completed to form a permanent self-anchored system, and then the cable force of the whole bridge is adjusted.

Main girder section: part of the main girder of the cable-stayed bridge adopts the concrete box girder section, and the part of the suspension bridge adopts the steel box girder section.

Material properties: C50 concrete is used for part of the main girder and wet joints of the cable-stayed bridge, and C30 concrete is used for pier piles; Q345 steel is used for part of the main girder of the cable-stayed bridge.

Load class: Highway—Class I.

Material characteristics of stay cables and main cables: Stay cables and main cables are twisted cables with extruded sheath.

Claims (1)

1. Self-anchored cable-stayed-suspension cooperative bridge, which is characterized in that the cable-stayed bridge part is constructed first, then the main cable is suspended, the main cable is temporarily anchored on the frame structure formed by multiple side piers, and then the part of the suspension bridge is hoisted The steel main girder, after the main girder is closed, completes the transformation from the ground anchor system to the self-anchored system, forming a permanent self-anchored system.

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