In the early hours of August 25, the swivel T-shaped structure of the Jianpozhai Grand Bridge on the Guiyang-Nanning High-Speed Railway's link into the Guiyang hub, built by China Railway No. 8 Engineering Group, successfully completed a 41.2-degree rotation after going through three stages—normal rotation, decelerated rotation, and inching rotation—and precise attitude adjustment, achieving closure with the bridge segments at both ends above the Shanghai-Kunming High-Speed Railway, making it the first bridge in Guizhou to be constructed using the swivel method over a high-speed railway.

The Jianpozhai Grand Bridge is located in Gui'an New Area, Guiyang, with a total length of 2,287.446 meters and a total of 78 piers and abutments, making it a major and difficult control project. The bridge is adjacent to an operating railway line, and construction adopted the "build first, then rotate" approach, with two piers spanning the railway line. Among them, the foundation pit of Pier 52 is only 21.65 meters in minimum plan distance from the centerline of the Shanghai-Kunming Railway. Overlooking the construction site, the three railway lines form a "≠" symbol shape within the limited space.

It is understood that the Shanghai-Kunming High-Speed Railway handles 75 trains per day, with a train passing roughly every 20 minutes or so, indicating high operating density and high safety risks for on-site construction. To avoid affecting the normal operation and traffic safety of the existing railway, the project department of China Railway No. 8 Engineering Group for the Guiyang-Nanning High-Speed Railway's link into the Guiyang hub established a safety team to strictly control the "red line" of construction adjacent to operating lines while accelerating project progress. Mechanical operations adhered to the "one machine, one guard" principle, and multiple mechanisms such as video monitoring and safety guards standing by were used to ensure safe and orderly construction.

"We used BIM technology to simulate the entire rotation construction process, collected various parameter data during rotation, formulated corresponding preventive and emergency measures for various situations that might arise during rotation, and organized all personnel to conduct construction rehearsals and rotation tests, ensuring controllable safety technology during rotation construction and ensuring the smooth progress of this rotation construction," introduced project manager Zhang Qiang. Before the rotation construction, the project department conducted multiple safety and technical training and briefings for on-site personnel, and used a tensioning jack system to carry out weighing, counterweight testing, and trial rotation of the swivel beam, ensuring zero-risk and high-efficiency completion of the rotation process.

At 0:11 a.m. on the 25th, with a command from the on-site chief commander, the bridge rotation construction began. Two jacks continuously pulled the 7,500-ton concrete box girder to rotate slowly counterclockwise. After 41 minutes of intense and orderly operation, the 160-meter-long T-shaped bridge precisely connected with the bridge body above the Shanghai-Kunming Railway and was successfully positioned. At this point, the minimum vertical distance between the bottom of the swivel beam and the catenary of the Shanghai-Kunming Railway was only 10.049 meters, and the side-span closure segment construction was only 7.83 meters from the Shanghai-Kunming High-Speed Railway.

The successful closure of the bridge body marks the basic completion of the offline works of the Gui'an section of the Guiyang-Nanning High-Speed Railway's link into the Guiyang hub. At this point, the addition of Gui'an Station to the Guiyang-Nanning High-Speed Railway "online" is just around the corner.