Mixed tensioning light prefabricated small box girder structure and construction method

Abstract

The invention discloses a mixed tensioning light prefabricated small box girder structure and a construction method. A small box girder comprises a top plate, web plates and a bottom plate; the web plates and the bottom plate are both of a span medium-thickness structure; the bottom plate is provided with steel strands; the steel strands are linearly arranged and are constructed by adopting a pre-tensioning method process; the web plates are provided with a plurality of slow-bonding steel strands; the projection of each slow-bonding steel strand on the vertical face of the corresponding web plate is arranged in a curve mode and anchored to the beam end of the corresponding beam; the diameter of each slow-bonding steel strand is larger than that of the steel strands, and a post-tensioning process is adopted for construction. The construction method comprises the steps of 1 prefabricating a single beam; 2 erecting the single beam; 3 carrying out cast-in-place of inter-beam diaphragm plates; 4 carrying out wet connection on bridge deck slabs between the cast-in-place beams; and 5 carrying out cast-in-place paving. The structural weight of the small box girder can be reduced by about 15% compared with that of a traditional structure, the economical efficiency is reduced by about 10% compared with that of an original traditional small box girder, construction is more flexible, the field influence is smaller, and weight reduction and prefabrication of a lower structure are better facilitated through weight reduction.

Description

technical field [0001] The invention relates to the technical field of box girder construction, in particular to the construction and construction method of a lightweight prefabricated small box girder with mixed tension. Background technique [0002] Prefabricated small box girder has become a conventional post-tensioned prefabricated bridge structure that is widely used in new urban viaducts due to its mature technology, relatively economical cost, and convenient construction. [0003] At present, the side girders of prefabricated small box girders are usually prefabricated and assembled together with anti-collision guardrails, and are installed as a whole on site. Although the problems of safety in the construction of anti-collision guardrails and on-site images have been solved, due to the slightly larger self-weight of the single girder, combined with the overall prefabrication of the anti-collision guardrails , the weight increases, the construction flexibility is also...

AI Technical Summary

Problems solved by technology

[0003] At present, the side girders of prefabricated small box girders are usually prefabricated and assembled together with anti-collision guardrails, and are installed as a whole on site. Although the problems of safety in the construction of anti-collision guardrails and on-site images have been solved, due to the slightly larger self-weight of the single girder, combined with the overall prefabrication of the anti-collision guardrails , the weight increases, the construction flexibility is also reduced, the requirements for mechanical equipment are increased, and the impact on the site is correspondingly increased

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