What is the " extraordinary " of Zhanlin Yellow River Bridge，let us take a look!

Design sketch of Zhanlin Yellow River Bridge

In China, construction technology of bridge is developing. A new bridge in Shandong Province, Zhanlin Yellow River Bridge, is under construction. As the bridge with the largest span in the lower reaches of the Yellow River, it will be the first bridge by full section jacking construction in China.

Full section jacking construction of Zhanlin Yellow River Bridge

Extremely lightweight structural design

Zhanlin Yellow River Bridge is a key control project of Zhanlin Expressway. This bridge is a 962m double tower composite beam cable-stayed bridge, with a main span (crossing the Yellow River) of 442m, which is the largest span in the lower reaches of the Yellow River at present.

Design sketch of Zhanlin Yellow River Bridge

The bridge is located in the lower reaches of the Yellow River where is not navigable. The main span section can not be transported and hoisted by river.

The bridge is located in the lower reaches of the Yellow River where is not navigable. The main span section can not be transported and hoisted by river.

The "full section" jacking construction method is not disturbed by the terrain and water flow under the bridge. In the traditional jacking method, the beam without bridge cover plate is pushed first, and then the bridge cover plate is superimposed.

Compared with the traditional method, the full section jacking of Zhanlin Yellow River bridge can realize the integrated jacking with bridge beam and cover plate, which takes less time, but has higher requirements on the material performance and manufacturing process of bridge concrete components. The key is "UHPC cover plate".

UHPC cover plate

Why UHPC?

Compared with the traditional reinforced concrete, the mechanical properties of UHPC with appropriate reinforcement are close to the steel structure, which can not only avoid the risk of cover plate fracture during full section jacking, but also has ultra-thin and ultra-high performance, so that the span of 962m can be pushed at one time and formed directly.

The lighter and stronger UHPC plate makes the bridge jacking construction faster, which is highly in line with the green and low-carbon development.

Why use UHPC now?

In fact, as early as 1998, Professor Qin Weizu of Tsinghua University has carried out research and promotion of UHPC in China. However, it is an innovative practice to integrate UHPC with cover plate for direct jacking construction. Without rich experience and superb skills, there will be lots of difficulties.

Zhanlin Yellow River Bridge project team by the First Highway Bureau Group 

of the China Communications Construction Company(CCCC) 

The key of integration of UHPC and cover plate is accuracy. During the prefabrication stage, the size, thickness, position deviation of embedded parts, etc. of each UHPC cover plate must reach the "millimeter level" accuracy.

Customized production line

High standard production process

High temperature steam curing

The steel-concrete composite beam of Zhanlin Yellow River Bridge has a total of 80 segments, with a maximum length of 12m, width of 38m and maximum weight of 410 tons. One segment is composed of side box, longitudinal and transverse beam, air nozzle and 4 UHPC cover plates.

The project team transported the panels and steel members of the composite beam, and fabricated these members and components at the bridge head area, which greatly reduced the risk and construction cost.

Divide the whole into pieces and "build blocks" at the bridgehead

Advanced modern bridge construction technology

The "extremely lightweight" structural design and the application of high-strength materials make the full section jacking of steel-concrete composite beams a reality. However, the construction of 962m and 27000 tons is still difficult at the forefront of the industry. Ensuring linear accuracy and avoiding steel structure deformation and panel cracking are always the top priority of construction control.

Full-section jacking construction with bridge deck

Monitoring Center

The remote wireless stress monitoring system and Beidou satellite positioning system are the "health detector" of the composite beam in the pushing process. Through real-time monitoring and early warning, automatic data analysis and other functions to ensure the healthy "walking" of the composite beam at each step.

The remote wireless video monitoring and calling system is the "sky eye" of construction management. It carries out weather monitoring on the site, and cooperates with the remote calling function to make the construction process all-round visual and barrier free communication.

The builders of CCCC First Highway Bureau Group have adopted the advanced technology, built the mighty steel and concrete dragon on the Yellow River successfully.

It is expected that the successful practice of full section jacking of steel-concrete composite beams will bring a new leap to China Bridge in the near future!