A giant dragon flies across the mountains of northern Guizhou! Tongzi River Bridge is completed and opened to traffic

Author: Li Chuanfu Shi Xiangqi

September 13, 2024 is a memorable day. The Jinsha-Renhuai-Tongzi Expressway (Jinrentong Expressway) in Guizhou Province is fully opened for trial operation. This 102.39-kilometer expressway is not only an important channel connecting western Guizhou and Chongqing, but also a masterpiece of engineering technology and innovation. Among them, the most eye-catching is the world's first high-low tower single-sided pile-free foundation large-span suspension bridge - Tongzi River Bridge.

On September 13, vehicles drove on the Tongzi River Bridge on the Jinrentong Expressway (drone photo). Photo by Xinhua News Agency reporter Liu Xu

1. Overview of Jinrentong Expressway

Jinrentong Expressway, as an important part of Guizhou Province's expressway network, is 102.39 kilometers long, 25.5 meters wide, and designed as a two-way four-lane road with a speed of 80 kilometers per hour. There are 60 bridges, 26 tunnels, 12 interchanges, 9 toll stations, 2 parking areas, 2 maintenance areas, and 2 pairs of service areas along the entire line. The completion of this expressway not only greatly shortens the time and space distance between western Guizhou and Chongqing, but also serves as an important link between the Qianzhong Economic Zone and the Chengdu-Chongqing Economic Zone.

2. Technical Innovation of Tongzi River Bridge

Tongzi River Bridge, located at the junction of Zunyi Renhuai City and Tongzi County, is the only technically complex special bridge on the Jinrentong Expressway. This steel truss suspension bridge with a total length of 1,422 meters and a main span of 965 meters is about 365 meters from the river valley. Its anchoring system uses a combination of tunnel anchors and gravity rock anchors. The high and low towers on both sides of the river adopt the form of pile group foundation and expanded foundation respectively. The most striking thing is that the Renhuai shore bridge tower adopts a pile-free foundation design, which is the first time in the world.

Technological innovations:

1. Pile-free foundation design: In the construction of the Renhuai shore bridge tower, due to the particularity of the karst landform, there is a large cave underground. In order to ensure safe construction, a pile-free foundation design was finally adopted. This design not only improves the stability of the bridge, but also reduces the impact on the environment.

2. High-strength galvanized aluminum parallel steel wire: The main cable adopts 1960Mpa high-strength galvanized aluminum parallel steel wire. The use of this material optimizes the number of cable strands from 114 to 91, significantly reducing the scale of tunnel anchors, shortening the construction period, and improving the durability of the bridge.

3. Steel truss design in the form of a corbel: The steel truss is designed in the form of a corbel, with the permanent hanging point cantilevered on the outside of the main truss. This design is both beautiful and practical, and improves the structural stability of the bridge.

III. Challenges and Responses during the Construction Process

The terrain along the Jinrentong Expressway is complex, with mountains and canyons interweaving, widespread karst landforms, dense high-gas sections in tunnels, and many faults, mud and water bursts and other unfavorable geological conditions. Faced with these challenges, the builders gave full play to the leading role of technical standards and actively promoted the application of "four new" technologies. They applied for 50 patents and 17 construction methods along the entire line, and a number of new equipment, new processes, new materials, and new technologies were used at different work sites along the entire line.

IV. Significance to Regional Development

The opening of Jinrentong Expressway has shortened the driving time from Tongzi County to Zunyi Maotai Airport from 2 hours to 45 minutes, and the driving time from Renhuai to Tongzi has been shortened by nearly half to less than 1 hour. This has not only greatly facilitated the travel of people along the route, but also played an important role in promoting the development and utilization of industries along the route and the rapid development of regional tourism.

The completion and opening of the Tongzi River Bridge is not only a major milestone in Guizhou's transportation construction, but also a leap forward in China's bridge engineering technology. This bridge is not only a major transportation route connecting the two places, but also a monument to China's wisdom and innovative spirit. In the days to come, it will continue to witness the development and changes of the mountainous areas in northern Guizhou, and become the pride of Guizhou and even China.