Chinese constructors set another world record

On September 9, at 7:20 a.m., the third pier of the Nanniwan Airport Bridge on the Yan'an East Ring Expressway, constructed by China Railway Seventh Group Co Ltd, completed a successful 90-minute rotation.

The bridge features a 67 meters height, a 33.6 meter-wide deck and a 54.5 meter tall single thin-walled hollow pier. Weighing 25,000 tons, it is the world's tallest, heaviest, and longest-span upper-rotating bridge.

The bridge pivot system is located 47.7 meters away from the pier body, right next to the operating Baotou-Xi’an Railway. The project faces high risks, complex construction procedures, and various technical challenges.

Faced with difficulties and challenges, the project construction team has overcome various technical difficulties through BIM (Building Information Modeling), structural calculation, and dynamic simulations of the construction process. Their efforts ultimately resulted in one provincial-level construction method and one nationally authorized invention patent.

Guo Jiye, project manager of the Yan'an Cross Railway Bridge Project Department of China Railway Seventh Group Xi'an Company, said that the core technology of bridge rotation lies in the key rotation process. The construction team adopts the internationally advanced "support-type ball joint + intelligent control" technology. The ball joint, considered the "heart" of the rotation system, weighs 33 tons and is precisely positioned under the supervision of digital monitoring and BIM simulation technologies. Its high-performance sliding surface ensures low friction and high load-bearing capacity, laying a solid foundation for smooth rotation.

Hundreds of builders worked day and night for 900 days to successfully complete this bridge, marking a milestone in China’s highway construction.

The Yan'an East Ring Expressway project is located in the southeast of Yan'an City, Northwest China's Shaanxi province, passing through Baota district and Ganquan county.

Upon completion, it will form a high-speed ring around the central urban area of Yan'an together with Baotou-Maoming and Changzhi-Yan'an expressways, serving as a new north-south corridor between Yulin and Xi'an, and playing a  significant role in the urban and economic development of the Yan'an Revolutionary Base Area.