Wide-width large-span hybrid beam extradosed cable-stayed bridge system and construction method thereof

Abstract

The invention discloses a wide-width large-span hybrid beam extradosed cable-stayed bridge system and a construction method thereof. The wide-width large-span hybrid beam extradosed cable-stayed bridge system comprises hybrid beams which are composed of concrete box girders and corrugated web steel box-concrete composite beams and arranged on two sides in a transverse bridge direction, wherein the concrete box girders are positioned on two sides of a middle fulcrum and are integrally poured with a bridge tower; the composite beams are located in side span and middle span; the concrete box girders and the composite beams are connected through a steel-concrete combined section; the steel-concrete combined section is formed by pouring combined section concrete in a corrugated web steel box; the hybrid beams are transversely composed of middle fulcrum concrete cross beams, truss type steel cross beams, I-shaped steel cross beams and end cross beams which are connected; a bridge deck is arranged on the hybrid beams; and the hybrid beams are supported by main piers and transition piers. The hybrid beam extradosed cable-stayed bridge system is reasonable in structural design, convenient to construct, good in using effect and capable of being used for wide and large-span bridges. Meanwhile, the invention further discloses a matched construction method. The matched construction method comprises the steps of bridge tower construction, concrete box girder construction, composite beam construction, steel-concrete combined section construction and the like. The construction method is complete, and construction progress is fast.

Description

technical field [0001] The invention relates to the technical field of bridge structures, in particular to a wide-width and long-span composite beam low-tower cable-stayed bridge system and a construction method thereof. Background technique [0002] The low-tower cable-stayed bridge, also known as a partial cable-stayed bridge, is a structural system between the continuous beam bridge and the cable-stayed bridge. Because it has both the structural advantages of the continuous beam bridge and the cable-stayed bridge, it has a wider application application. [0003] The main girder of traditional low-tower cable-stayed bridges mostly adopts single-box single-chamber or multi-chamber concrete box sections. Although such sections can provide greater rigidity, there are also inevitable technical problems: [0004] (1) For wide-width bridges, single-box multi-chamber sections are often used, which greatly increases the volume of concrete, which increases the negative bending mom...

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Problems solved by technology

[0004] (1) For wide-width bridges, single-box multi-chamber sections are often used, which greatly increases the volume of concrete, which increases the negative bending moment of the pier top of the main girder under the action of its own weight, which seriously affects the mechanical performance of the main girder, and is easily Cracks on the top surface of the main girder on the top of the pier

[0005] (2) For long-span bridges, the mid-span adopts concrete box section, which greatly increases the mid-span positive bending moment of the main girder and the negative bending moment of the pier top, which makes the mid-span box girder bottom plate and the mid-fulcrum box girder top plate very easy to crack, seriously It affects the mechanical performance and performance of the main girder. At the same time, due to the increase of the main girder bending moment, it is necessary to configure a large number of prestressed steel bars and large-sized cable-stayed cables, resulting in unnecessary waste of materials and increasing the cost of low-tower cable-stayed bridges. , affecting its economic performance

[0006] (3) Due to the stress characteristics of single-box single-chamber or multi-chamber concrete box sections, the pylons of short-tower cable-stayed bridges are mostly arranged in the central divider, and the central cable plane is used. For wide bridges, due to the transverse width The increase of the main girder will make the lateral force of the main girder more complex, and the shear lag effect will be obvious, resulting in a decrease in the mechanical performance of the main girder. At the same time, due to the limited position of the bridge tower, the structural form of the bridge tower is mostly a single-column tower with a single form. Not suitable for higher landscape requirements

[0007] (4) The structural system of the traditional short-tower cable-stayed bridge greatly limits its application to wide-width and long-span bridges, and also limits its diverse landscape development

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