On March 12th, after more than 30 consecutive hours of pouring, the No. 0 block of the first main pier (No. 6 pier) of the Xuantian Lake Double-Line Bridge along the Chengyu Central High-Speed Rail Line was successfully poured, marking the transition from the substructure to the superstructure construction for this bridge with the highest environmental protection requirements along the whole line.
The Chengyu Central High-Speed Rail Line starts from Chongqing North Station in Chongqing hub, heading westward through Yubei District, Shapingba District, Bishan District, Tongliang District, and Dazu District of Chongqing, as well as Ziyang City and Chengdu City of Sichuan Province, leading into Chengdu hub’s Chengdu Station. The main line is 292 kilometers long with a designed speed of 350 km/h. The Xuantian Lake Double-Line Bridge is located in Tongliang District, Chongqing, spanning across the 4A-level Xuantian Lake scenic area, which is a habitat for swans. The bridge is about 460 meters long with 8 piers and 2 abutments, among which piers No. 4, 5, and 6 are in the Xuantian Lake with a maximum water depth of 13 meters, posing high environmental protection requirements and construction difficulties.
According to the introduction, the No. 0 block of the main pier No. 6 at the Xuantian Lake Bridge measures 12 x 12.6 x 10.25 meters (length x width x height), with about 610 cubic meters of concrete. The on-site construction adopted the cantilever casting method. The successful pouring of the No. 0 block provides an assembly platform for the subsequent use of an intelligent cantilever bridge machine, laying a solid foundation for the construction of the main continuous beam body.
Furthermore, the project team optimized the alignment by reasonable route selection and detailed modeling calculations, designing the shortest viaduct crossing the Xuantian Lake and reducing 27 steel pipe piles in the water, minimizing the impact on the water environment during construction. To ensure the normal construction of the water piers and pier bodies, three giant lock-type steel pipe pile cofferdams were used to isolate the construction area from the water body, preventing any wastewater from flowing into Xuantian Lake. Additionally, the project department is equipped with a new environmental monitoring system that conducts real-time monitoring of water quality, temperature, humidity, noise, wind speed, and air quality, with AI monitoring and early warning capabilities. So far, the local water conservancy authorities have conducted multiple inspections in the area, all indicating no changes in water quality.
According to the construction plan, the main body of the entire bridge is expected to be completed within this year. The Chengyu Central High-Speed Rail Line is an important part of China’s “Eight Vertical and Eight Horizontal” high-speed rail network along the Yangtze River corridor. Upon operation, it will further improve the transportation network structure in the Chengdu-Chongqing region, significantly reducing travel time between the two cities and greatly facilitating travel for residents along the line. It holds great significance in supporting the construction of the Chengdu-Chongqing Economic Circle and forming a new landscape for the development of western China.