On January 20, with the successful lowering of the 530-ton cutterhead into the shaft, all components of the "Yunhe" shield machine for the Beijing East Sixth Ring Road (Jingha Expressway—Luyuan North Street) Reconstruction Project have been lowered into the shaft, and the project is about to enter a new stage of shield tunnel construction.
The "Yunhe" shield machine consists of a cutterhead, a shield body, and five trailer sections. Since the first component——Trailer No. 1——was hoisted and lowered into the shaft in late December 2020, the contractor CCCC Tunnel Engineering Bureau has overcome difficulties such as a cramped work site, interference from multiple overlapping construction activities, a complex surrounding environment, and impacts on component transportation. Ultimately, it completed the hoisting and assembly of the shield machine components in just 30 days, setting a new construction record for similar projects in China.
It is reported that the Beijing East Sixth Ring Road Reconstruction Project is a key transportation infrastructure project for Beijing's sub-center. Among it, the 9.16-kilometer tunnel section will use the shield method for 7.4 kilometers of construction, making it the underground road tunnel project with the longest single excavation in China and the largest diameter in the mainland. The right-line tunnel of the project is contracted by CCCC Tunnel Engineering Bureau and will use the "Yunhe," a super-large-diameter slurry shield machine with a diameter of 16.07 meters independently manufactured in China, for north-to-south excavation.