On August 15, 2021, the maintenance and renovation project of the Shengli Yellow River Bridge undertaken by the China Railway 14th Bureau Group was completed to ensure that the full bridge will be opened to traffic at the end of 2021. The Shengli Yellow River Bridge has a total length of about 2.8 kilometers and is divided into a main bridge and a north-south approach bridge. It was completed on October 1, 1987. It was the longest steel cable-stayed bridge in Asia at that time.

The main bridge of the bridge is a double-tower five-hole continuous steel cable-stayed bridge with a total length of 682 meters. The cables are arranged as a double-cable fan-shaped multi-cable system. There are 88 cable stays in the whole bridge with a cable distance of 12 meters, except for the farthest distance from the tower. The stay cables are two, and the rest are single cables, each of which is a group of 4, a total of 20 groups, and each of the two main towers in the north and south has 10 groups. With the extension of the use time, the safety hazards of the Shengli Yellow River Bridge have become more prominent. After a comprehensive inspection, the main bridge is assessed as a category four bridge, and the approach bridge is assessed as a category five dangerous bridge.

In order to adapt to the healthy development of the surrounding areas, to create an ecological community in the lower Yellow River, and to effectively improve and eliminate hidden traffic safety hazards, the China Railway 14th Bureau Group will repair and renovate the bridge in November 2020. "The core of the maintenance and reconstruction of the Shengli Yellow River Bridge is the main bridge, and in the main bridge related projects, the cable replacement is one of the most critical points." The person in charge of the project introduced that the Shengli Yellow River Bridge has been in service for 33 years. Compared with the design, there are different degrees of deviation, and the largest change is about the weight of 100 scalpers weighing 400 kg.

Kenli District, Dongying City, where the bridge is located, is located in a temperate monsoon climate zone, close to the Bohai Sea, with high summer temperatures, high humidity and concentrated precipitation. The high temperature, high humidity and high salt climatic environment greatly damages the steel structure of the bridge; the steel box, the main stress member of the main girder The bottom plate, joints and the secondary stress-bearing components of the bridge deck are severely corroded, and the bridge deck is partially welded and the force is poor.

The complicated climatic environment, the extremely poor overall condition of the bridge, and the tight construction period posed great challenges to the replacement of stay cables.

In order to ensure the success of the cable exchange, the project department invited well-known experts at home and abroad to "pulse consultation" together. It is finally determined that the replacement of stay cables adopts the construction plan of replacing the same number of stay cables on the four cable faces of the same bridge tower at the same time, which mainly involves the release of old cables, the removal of old cables, the installation of new cables, the tension of new cables, and the cable force. Adjust five steps. According to the project leader Li Wei, 33 years ago, the Shengli Yellow River Bridge used foreign technology and technology. 33 years later, the repair and reconstruction of this bridge all used domestic advanced technology and technology.

The new cable adopts high-strength parallel steel cable with a standard tensile strength of 1860Mpa, which has excellent steel wire strength performance. In order to ensure the synchronization of the force of the 4 cables during tensioning, it is divided into 5 levels according to the monitoring instructions, and each level is finely controlled and graded. A single tower is equipped with 4 sets of tensioning and tensioning systems, and 4 cables on the same layer. The cable is synchronized, graded, symmetrically stretched and stretched.

In order to meet on-site construction, the engineering and technical personnel of the project department also independently designed and transformed the tower top hoisting bracket system, construction hanging basket platform, and circulating steel wire rope suspension system in combination with the original structure of the bridge, which greatly improved the construction efficiency and safety of cable replacement. Coefficient, the system summarizes a set of bridge cable replacement technology suitable for the construction conditions of the lower Yellow River.

As the first steel cable-stayed bridge in the country, the Shengli Yellow River Bridge has made great contributions to local economic development and the transportation between the two sides of the Yellow River. After the completion of the repair and renovation, it will rejuvenate its youth, effectively alleviate the current situation of heavy traffic pressure across the Yellow River, and continue to play the role of the north. Connecting the Beijing-Tianjin area and Dongying Port and most of the oilfields, the Nanlian oilfield base, the Jinan-Qingdao Expressway and the Jiaodong area are important traffic arteries, providing a safe and smooth traffic environment for regional economic and social development. Editor/Tian Zengpeng