Stretching Method of Prestressed Tendons of Long-span Curved Girder Bridges

Abstract

The invention discloses a prestressed rebar tensioning method for a large-span curve girder bridge. Balanced and symmetric tensioning is conducted with the axis of a box girder as the center; according to the tensioning sequence of prestressed steel strands on one side of the box girder, transverse steel strands on a beam of the box girder are tensioned first, then prestressed steel strands on middle and side webs of the box girder are tensioned in a crossed mode, then prestressed steel strands on the outer sides of bottom and top plates of the box girder are tensioned in a crossed mode, and finally transverse steel strands on the top plate of the box girder are tensioned. By adopting the method for tensioning the prestressed rebars, the deflection and stress of a girder body change smoothly, no crack is generated in the girder body in the tensioning process, and the construction quality is improved.

Description

technical field [0001] The invention relates to a construction method, in particular to a method for stretching prestressed tendons of a large-span curved girder bridge. Background technique [0002] The curved prestressed concrete continuous box girder bridge can well adapt to the complex alignment requirements of high-grade highways and urban interchange projects, and at the same time ensure the smooth, smooth, and bright aesthetic requirements of the curved structure lines. It has high economic indicators and has become a modern traffic bridge. Important bridge types in engineering. With the rapid development of highways and urban roads, its applications are increasing, and its span is also increasing. [0003] The long-span curved prestressed concrete continuous box girder bridge has the characteristics of complex mechanical performance and great difficulty in design and construction. In particular, the upper structure of the curved girder bridge adopts a continuous bo...

AI Technical Summary

Problems solved by technology

In particular, the upper structure of the curved girder bridge adopts the continuous box girder structure of the prestressed concrete oblique web with curved variable cross-section. The prestressed tendons are arranged in waves according to the stress mode of the bridge, and the positioning during the construction process is also complicated.

The complexity of the prestressing construction process during construction can easily lead to bad engineering problems in the process of prestressing tension, such as the overturning of the box girder due to the excessive torque difference between the inside and outside of the beam body, and the cracking of the concrete caused by uneven stress distribution. Therefore, the prestressed tendons The tensioning sequence must be strictly in accordance with the design requirements

At present, there is a lack of relevant methods for optimizing the tensioning sequence of prestressed tendons in curved girder bridges

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