Chongqing -  A new high-speed rail link is reshaping connections across western China. With a key bridge on the Xi’an-Chongqing High-Speed Railway completed, travel between the two cities is expected to be cut to about 2.5 hours, opening new opportunities for tourism, business and regional cooperation.

Located in Chongqing’s Chengkou County, the 941.6-meter Miaojialiang Bridge was built to overcome challenging terrain along the route. The structure features a 136-meter-long main span and a 103.5-meter-high pier, reflecting the engineering challenges involved in building the high-speed railway through mountainous areas.

The Miaojialiang Bridge on China’s Xi’an-Chongqing High-Speed Railway was completed on Oct. 12. Its tallest pier stands 103.5 meters high. (Photo/Chongqing Daily)

Constructing such a structure requires exceptional precision. Working at heights of more than 100 meters, engineers must maintain millimeter-level accuracy in the bridge's alignment and structural measurements while overcoming complex construction conditions.

To tackle these challenges, the project team introduced an intelligent hydraulic climbing formwork system, which works like a "mobile 3D printer" for bridge piers. Powered by a hydraulic system, the equipment can automatically climb upward along the pier, eliminating the need for repeated removal and installation of conventional formwork.

The technology has significantly improved construction efficiency. Each 4.5-meter pier section can now be completed in about four and a half days, increasing efficiency by around 30% compared with conventional construction methods.

Digital technologies have also been integrated throughout the construction process. The team developed a smart construction platform that continuously tracks key data, including bridge alignment, elevation, and stress changes. The system enables real-time monitoring of construction conditions and helped ensure accurate alignment during bridge closure.

Safety management has also been enhanced through an AI-powered bridge construction control system. The platform integrates tower crane monitoring, elevator safety monitoring, and remote video surveillance to automatically identify unsafe practices, including workers failing to wear helmets or safety harnesses, as well as unauthorized welding operations.

Spanning 739 kilometers, the Xi’an-Chongqing High-Speed Railway is designed to operate at speeds of up to 350 kilometers per hour. Once completed, the railway will strengthen connections between northwest and southwest China, shortening travel times between major cities and facilitating the flow of tourists, talent, goods and investment. 

It is also expected to support closer cooperation between the Chengdu-Chongqing economic circle and the Guanzhong Plain urban cluster, boosting regional industries, logistics and cultural exchanges.

One example is Chengkou County, a mountainous area at the intersection of Chongqing, Sichuan and Shaanxi. The county has long been limited by difficult terrain and transport conditions. The Xi’an-Chongqing High-Speed Railway is expected to bring it into a faster regional transport network, making it easier for tourists, businesses and local products to reach wider markets.