Recently, the first hole box girder of Section 8 in front of the Chongqing section of the Yifu High speed Railway, which was constructed by CRFG, successfully completed the pouring operation on the Changshou North Right Connection Line Extra Large Bridge. This move has accelerated the construction of the upper structure of the bridge in this section. The first hole box girder poured this time is a 32.6-meter single line prestressed simply supported box girder, constructed using the MSS32 upward moving formwork in-situ casting process. The formwork system weighs about 280 tons and has outstanding advantages such as high mechanization, excellent safety performance, and strong terrain adaptability. It can efficiently complete the cyclic operation of in-situ pouring of box girders and formwork hole displacement, effectively solving complex construction problems such as multiple bridges crossing roads and adjacent existing railways in the project.

Thoroughly deploy and build a solid foundation for construction

To ensure the smooth progress of the first hole box girder pouring work, the project department has planned in advance and fully completed the full process preparation work such as formwork assembly, grading preloading, and system debugging. At the same time, the pre compression test was completed according to the standard of 1.2 times the construction load, and the elastic deformation and non elastic deformation data were accurately calculated. The pre arching degree was scientifically set, providing a solid guarantee for the smooth progress and construction quality of the box girder pouring.

Strictly control quality to ensure that pouring meets standards

During the pouring operation, the project department strictly implements the requirements of safety penetration management, comprehensively carries out safety technical disclosure work, and conducts acceptance and verification of key links such as lifting equipment, hydraulic systems, and electrical systems one by one. Management personnel monitor the entire process on-site, while technical, safety, and testing personnel stand by to strictly control the construction quality of concrete mixing, transportation, pouring, vibration, and other aspects. The construction process adopts symmetrical fabric and layered pouring to ensure that the box girder is solid inside and beautiful outside. After continuous and uninterrupted operation, the first hole box girder was successfully formed, and all technical indicators met the design standards and specification requirements. Keywords: China Railway First Group, Yifu High speed Railway, pouring

The total length of Section 8 of the Chongqing section of the Yifu high-speed railway is 26.059 kilometers, with a bridge tunnel ratio of 85.8%. A total of 182 holes of mobile formwork cast-in-place beams need to be completed. The successful pouring of the first hole box girder marks a new stage of large-scale construction of the upper structure in the bridge construction of this project, and also accumulates valuable mature experience for subsequent large-scale box girder construction.Editor/Gong Ziwei