The world's bridges look to China, and China's arch bridges look to Guangxi. On the morning of January 10, with the successful welding of the last arch rib connection point, the main arch rib of the "world's No.1 arch" Pingnan Third Bridge achieved high-precision closure. The alignment error of the chord tubes at the closure opening is less than 3 millimeters, the lateral deviation of the arch axis is less than 10 millimeters, and the deviation between the arch ring alignment and the target alignment is less than 30 millimeters.


　　Academician Zheng Jielian of the Chinese Academy of Engineering stated

　　In terms of the installation of the cantilever-assembled main arch ring, this precision is at the world's leading level, representing another advancement in the construction technology of long-span arch bridges. The successful closure of the bridge's arch rib provides reliable technical support for the further development of long-span arch bridges, or in other words, in the near future, we will be capable of building arch bridges with even larger spans.

　　The Pingnan Third Bridge has a main span of 575 meters, making it the largest span arch bridge currently under construction in the world. It is also a major bridge crossing the Xun River on the Pingnan North Interchange connection line of the Lipu-Yulin Expressway. It is designed and constructed under the leadership of Academician Zheng Jielian of the Chinese Academy of Engineering, invested by Guangxi Communications Investment Group, and constructed by Guangxi Road and Bridge Group, a subsidiary directly under Guangxi Beibu Gulf Investment Group. The bridge has a total length of 1035 meters and will become a new calling card for Chinese bridges upon completion and opening to traffic.

　　Du Hailong, Executive Deputy General Manager of Guangxi Road and Bridge Group and Project Manager of Pingnan Third Bridge, introduced that the main arch ring of Pingnan Third Bridge consists of 44 segments. From the hoisting of the first arch rib segment on October 12, 2019, to the closure on January 10, 2020, the installation took only 90 days. The bridge construction adhered to meticulous craftsmanship. The verticality of all trench sections of the diaphragm wall is less than 1/400, far superior to the 1/200 required by specifications; all trench sections and pile foundations have been tested as Category I piles; the project applies systems such as Eagle Eye monitoring, tower crane monitoring, deep foundation pit detection, and intelligent concrete temperature control to achieve full coverage and zero-dead-angle supervision of the construction site and material management; BIM+ technology is applied to all stages of construction, using the 3D simulation dynamic demonstration function of the model to form a process-based management model of pre-simulation, process guidance, and finished product inspection. The project has now become a demonstration site for Building Information Modeling (BIM) technology application in Guangxi, awarded by the Guangxi Department of Housing and Urban-Rural Development. During construction, the project vigorously introduced and promoted the "four new technologies" to reduce energy consumption and pollution, ensuring the implementation of the ecological civilization concept of "lucid waters and lush mountains are invaluable assets."

　　Link: Pingnan Third Bridge Achieves Many New Breakthroughs

　　——For the first time in China, the "diaphragm wall + pebble layer grouting scheme" was applied to the foundation construction of the arch abutment of a long-span arch bridge, setting a precedent for building long-span concrete-filled steel tube arch bridges under unfavorable geological conditions.

　　——Through prefabricated, integrated, and information-based means, the cable hoisting system was upgraded. Technologies such as the Beidou satellite positioning system and intelligent tensioning were adopted to replace passive stiffness control with active control, precisely controlling the deviation of the top of the 200-meter-high tower within 20 millimeters, reaching the industry-leading level.

　　——Initiated the "Calculation Theory of One-Time Tensioning for Concrete-Filled Steel Tube Cable-Stayed Buckle Based on the Influence Matrix Principle," achieving a new breakthrough in the alignment control technology of the bridge arch ring.

　　——Adopted the electrical control technology of a 300-ton cable crane, with the process reaching the industry-leading level.

　　——Carried out multiple scientific research projects and obtained 9 patents.

　　——The manufacturing precision of steel structures is controlled within 2 millimeters, and the rigorous process flow reaches the world's advanced level.