Core Viewpoint - The successful completion of the steel box girder rotation for the upgrade of the Shenhai Expressway marks a significant technical achievement, laying a solid foundation for the project's full connectivity [1][5]. Group 1: Project Overview - The Shenhai Expressway spans 359.079 kilometers within Shandong Province and is being upgraded to a dual eight-lane highway with a design speed of 120 km/h [3]. - The bridge, constructed by China Railway 10th Bureau, is located near the northern outer ring of Jiaozhou City and measures 275 meters in length [3]. - The steel box girder used in the bridge weighs 5,286 tons, making it the largest unequal span railway crossing steel box girder project in Shandong Province [3]. Group 2: Material and Structural Innovations - The entire bridge is made of weathering steel, which eliminates the need for traditional rust-proof coatings, thus saving construction time and extending the bridge's lifespan while reducing future maintenance costs [3][4]. - The bridge employs a fully welded structure, moving away from traditional bolt connections to mitigate risks associated with bolt loosening and replacement difficulties [3][4]. Group 3: Construction Challenges and Solutions - The bridge crosses two major railway lines, with over a hundred passenger and freight trains passing through the construction area daily, necessitating precise operations within limited time windows [4]. - Advanced technologies such as hole detection instruments and electronic curtain systems were utilized to ensure safety and precision during the critical rotation process [4]. - The project team implemented intelligent construction techniques to accurately calculate traction and safety factors, establishing a dynamic correction model to support the precise rotation [4][5]. Group 4: Strategic Importance - The Shenhai Expressway upgrade is a key project under Shandong Province's "14th Five-Year Plan" for comprehensive transportation, connecting several strategic development zones and important transportation hubs [5]. - Upon completion, the project is expected to enhance regional transportation service levels, optimize network structure, and promote economic integration in the Jiaodong Economic Circle [5].