In the early morning of April 12, the main span of the Yuanjiang Extra-long Bridge, the key control project of Changde-Yiyang-Changsha High-speed Railway Line, had a successful closure, marking the holing-through of the whole Changde-Yiyang-Changsha High-speed Railway Line designed by the overall designer CRCC SIYUAN.

The Yuanjiang Extra-long Bridge has a total length of 34.866 kilometers, with a 240-meter long main span. It is currently the world's largest high-speed railway bridge with a deep-water double-leg thin-wall pylon beam-pier consolidation system, being also a ballastless track continuous rigid frame cable-stayed bridge with the largest span in China’s 350 km/h high-speed railway.

The Yuanjiang Extra-long Bridge crosses the Yuanjiang River, the second largest river system of the Dongting Lake. With a high navigable grade and a large bridge span, the bridge’s design and construction difficulty ranks among the top in China. Wang Jie, who is in charge of the CRCC SIYUAN bridge discipline of Changde-Yiyang-Changsha High-speed Railway, introduced that the design finally adopts the scheme of continuous rigid frame for the main loading, meanwhile with the cable as stiffening, as a result, improving the overall stiffness of the structure, and ensuring the comfort and safety of the high-speed railway operation.

In the construction of the main pier of the bridge, the diameter of the double-wall steel cofferdam is 38.5 meters, the height is 46.4 meters, the depth of the cofferdam into the river bed is 15 meters, and the amount of concrete poured at the bottom of the bridge is 9,368 cubic meters. The hydrological and geological conditions at the foundation location of the bridge’s main pier are very complicated. "We use super-long bored pile with large diameter, and the actual bored depth reaches 128 meters. The design and construction difficulty of deep-water bored pile foundation + super-high double-wall steel cofferdam is rarely seen in China." Mr. Huang Zhongping, the director of CRCC SIYUAN bridge discipline said.

Changde-Yiyang-Changsha High-speed Railway Line, starting from Changde in the west, and ending in Changsha in the east, with a total length of 157.5 kilometers and a design running speed of 350 km/h, is jointly constructed by the following participants: China Railway 11th Bureau Group Corporation Limited, China Railway 11th Bureau Group Corporation Limited, China Railway 12th Bureau Group Corporation Limited, China Railway 20th Bureau Group Corporation Limited, China Railway 24th Bureau Group Corporation Limited, China Railway 25th Bureau Group Corporation Limited, China Railway Construction Electrification Bureau Group China Railway SIYUAN Group Corporation Limited, China Railway Fifth Survey and Design Institute Group Corporation Limited, China Railway Urban Construction Group Corporation Limited, etc. It is an important component of two major channels in the national "eight longitudinal and eight latitudinal" high-speed railway network, i.e. Xiamen-Chongqing, and Hohhot-Nanning. After the whole line put into traffic, it will only take 1 hour from Changde to changsha, and the integration between the city cluster of Changsha, Zhuzhou, Xiangtan and the industrial belt of Yiyang and Changde will be closer, which has a vital significance in optimizing Hunan’s northwestern transportation structure.