Large-section simply-supported box girder precasting and assembly process under conditions of strong wind and high altitude

Abstract

The invention discloses a large-section simply-supported box girder precasting and assembly process under the conditions of strong wind and high altitude, wherein construction simply-supported box girders are single-hole girders or porous girders, each hole girder in the simply-supported box girders is formed by assembling a plurality of box girder sections, and each hole girder is supported and fixed by two bridge abutments arranged at the bottoms of the left end and the right end of the hole girder. The process includes the following steps: 1. concentrated precasting for the box girder sections: including production and installation for frameworks of steel reinforcements, form erecting, concreting and closed girder section life preserving; 2. assembly construction for the first hole girders in the single-hole girders or the porous girders: including girder section transfer, linear adjustment and girder section assembly; 3. construction for the next hole girders; and 4. repetition ofthe step 3 for multiple times till all construction processes of the construction simply-supported box girders are completed. The process is reasonable in design, simple in the steps, convenient in implementation and good in construction effect, the construction shaped simply-supported box girders are high in quality, and therefore, the process is especially suitable for large-section simply-supported box girder precasting and section assembly construction under the conditions of strong wind and high altitude.

Description

technical field [0001] The invention belongs to the technical field of segmentally assembled simply supported box girder construction, and in particular relates to a prefabrication and assembly process of a large cross-section simply supported box girder under conditions of strong wind and high altitude. Background technique [0002] Nowadays, the segmental assembly wet joint construction process of the segmental assembly bridge building machine is as follows: first, the prefabricated beam section is transported and hoisted to align, and the prefabricated beam section is transported by the beam transport vehicle from the beam section prefabrication yard to the tail of the bridge building machine , the beam section is hoisted to the installation position by the gantry crane of the bridge building machine, and the three-dimensional position of the prefabricated beam section is adjusted to make it reach the designed line shape. In the adjustment of the beam section, the most im...

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Problems solved by technology

[0004] During actual construction, under the extreme climatic conditions of dryness, strong wind, and large temperature difference in the Gobi region of Xinjiang, when prefabricating each box girder segment, it is difficult for the concrete to obtain moisture from the outside during the curing period, and the internal moisture will be large It is lost to the outside, which makes the cement hydration insufficient, and accelerates the plastic shrinkage, autogenous shrinkage, drying shrinkage and other shrinkage deformation of the concrete during the construction stage and the later hardening stage, resulting in poor early stability of the concrete and cracking. Therefore, the prefabricated quality of the box girder not easy to guarantee

In addition, during the construction of box girder segments, especially when controlling the alignment of the beam body, there are many practical problems such as complicated operation, inconvenient control, and difficulty in meeting the design requirements for the alignment of the beam body in the bridge state.

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