On April 25, the four bridges of the G5 Beijing-Kunming Expressway Chengdu-Mianyang expansion project, with a total weight of 76,000 tons, were synchronously rotated into place during 66 minutes of intensive work, safely crossing the Dazhou-Chengdu North Ring connecting railway and the Chengdu North Ring railway hub, laying a solid foundation for the subsequent construction of the Chengdu-Mianyang expansion project of the Beijing-Kunming Expressway. The photo, taken on April 24 by drone, shows the construction site of the four expressway bridges before rotation. (China News Service reporter Liu Zhongjun)

　　On April 25 in Chengdu, Sichuan, an aerial view of the site after the four bridges of the Chengdu-Mianyang Expressway expansion project successfully completed their rotation. On that day, the four bridges of the G5 Beijing-Kunming Expressway Chengdu-Mianyang expansion project, with a total weight of 76,000 tons, were synchronously rotated into place during 66 minutes of intensive work, safely crossing the Dazhou-Chengdu North Ring connecting railway and the Chengdu North Ring railway hub, laying a solid foundation for the subsequent construction of the Chengdu-Mianyang expansion project of the Beijing-Kunming Expressway. (Drone photo by China News Service reporter Liu Zhongjun)

　　At 0:15 a.m. on April 25, the synchronous rotation operation of the four bridges in the Qingbaijiang section of Chengdu, part of the G5 Beijing-Kunming Expressway Chengdu-Mianyang expansion project, was launched, with construction personnel performing their respective duties and making all preparations for the rotation operation.

　　At 1:40 a.m. on the 25th, the rotation of the four bridges began. Four sets of intelligent hydraulic jacks, under unified computer control, pulled the steel strands, slowly driving the spherical hinges within the rotation system to rotate, and the four bridges began to turn slowly. During the rotation, construction personnel closely monitored changes in the bridges' rotation angle, continuously measured the rotation coordinates, and precisely controlled the rotation process through a BIM digital twin system. At 2:46 a.m., after 66 minutes of smooth rotation, the four bridges achieved precise docking with the main bridge. "To minimize the impact of construction on railway transportation, the bridges were prefabricated on both sides of the railway line first, and then the bridge bodies were rotated at a height of more than 20 meters using a hydraulic jack system, ensuring the normal passage of China-Laos, China-Europe freight trains and other freight trains," said Zeng Jun'en, chief engineer of the project at Chengdu Railway Engineering General Contracting Company.

　　The four overpass rotating bridges of the G5 Beijing-Kunming Expressway Chengdu-Mianyang expansion project are located within Qingbaijiang District, Chengdu. Two of the rotating bridges cross the Chengdu North Ring Line, each weighing about 16,000 tons and requiring a clockwise rotation of 77.9 degrees; the two rotating bridges on the north side need to cross the Dacheng North Ring connecting line, requiring a counterclockwise rotation of 71.8 degrees, with one of the bridges weighing 28,000 tons.

　　After the four bridges of the G5 Beijing-Kunming Expressway Chengdu-Mianyang expansion project, with a total weight of 76,000 tons, were synchronously rotated into place, a solid foundation was laid for the subsequent construction of the Chengdu-Mianyang expansion project of the Beijing-Kunming Expressway.