Industrial Design and Economic Analysis of Steel Box Girder Bridge with Conventional Span

To improve the industrial construction level of steel bridges, a prefabricated continuous steel box girder bridge was designed in this study, which is suitable for bidirectional four lanes and six lanes with spans ranging from 40 m to 80 m. The overall dimensions and local structures of the steel box girder bridge were determined according to the specifications and engineering experience, and the load-bearing capacity was checked. Modular industrial products were designed by defining the vertical and horizontal modular divisions for the steel box girders, resulting in 21 standardized modular components. Based on the concept of life cycle, an economic analysis of the prefabricated steel box girder bridge was carried out. Research results show that the overall dimensions and local structures of the prefabricated steel box girder bridge are reasonable. The modular product design improves the versatility of steel box girder bridges across different spans and lanes, greatly simplifying the construction process to meet industrial construction requirements. When considering the whole life cycle and the recovery of steel materials, the average annual cost of prefabricated steel box girder bridges is only about 30% of that of concrete girder bridges. Additionally, its carbon emissions during the construction phase are lower than those of concrete girder bridges, providing a significant economic advantage over the entire life cycle.