At 18:15 on June 18, at the construction site of the Hefei Qingxi Road railway-related project undertaken by China Railway 24th Bureau, the country's first synchronous incremental launching of three linked steel box girders with a total weight of 10,000 tons crossed over a high-speed railway station yard, marking the successful completion of the steel box girder launching construction of Hefei's Qingxi Road over the downline "throat area" of Hefei West Railway Station, and laying a solid foundation for the next step of achieving full-line connectivity.

Launching construction completed (Photo by Li Kangkang)

The steel box girder bridges of the Qingxi Road main line bridge, Ramp A and Ramp D launched this time are located in the "throat area" at the north end of the newly built Hefei West Railway Station yard, vertically crossing 5 tracks including the existing Hewu, Hefu and Shibagongli dedicated lines, with a maximum launching distance of about 62 meters and a maximum longitudinal slope of 4.5%. The total launching weight of the three linked steel box girders exceeded 10,000 tons. The successful completion of the synchronous launching construction of the three linked steel box girders crossing the high-speed railway station yard provides valuable experience and reference for similar projects in China.

As the core part of the Qingxi Road railway-related municipal road project, the steel box girder launching construction across the railway must accurately and efficiently complete the set tasks within the limited daily 4-hour and 15-minute railway blockade period. The synchronous launching of three linked steel box girders across the high-speed railway station yard involves complex construction, difficult alignment control and high safety risks. How to ensure the construction safety of the railway operating line and achieve precise control of synchronous launching became a major challenge and key difficulty faced by the project.

During construction, the project department adopted the walking-type launching process, using three-dimensional jacks and a hydraulic synchronous control system to perform vertical lifting, horizontal launching and lateral deviation correction of the steel box girders, repeatedly "lifting, launching, correcting, lowering and returning" the three linked steel box girders at a launching speed of 1.5 to 2 meters per hour, and successfully completed the launching task in 13 days over a total of 3,315 minutes.

To ensure the construction safety of the operating line, the project department, with the operating line innovation studio as the carrier, carried out in-depth scientific research cooperation with Tongji University, installed 60 strain gauges inside the steel box girders, and used the BeiDou satellite positioning system to conduct real-time monitoring, dynamic perception and timely deviation correction of the posture, alignment and stress state of the steel box girders during launching, controlling the accuracy within 5 millimeters and minimizing the impact of steel box girder launching on high-speed railway operations.

The railway-related municipal road project in the New Hefei West Railway Station area (Qingxi Road), as a supporting municipal project of the New Hefei West Railway Station, connects to the Silihe Road elevated road in the north and to the connecting ramp of the north drop-off platform in the south. After completion, the project will achieve a rapid connection between the north and south drop-off platforms of the new high-speed railway west station, effectively relieve the traffic pressure at regional crossings, build a fast-in and fast-out pattern for the road network around the New Hefei West Railway Station area, further improve the traffic in the area, and is of great significance for promoting station-city integration and the development of western Hefei.