On May 21, the "Yunqing No. 1" shield machine successfully launched for the No. 2 underpass passage of the Phase III expansion project of Guangzhou Baiyun International Airport, the largest expansion and reconstruction project in the history of civil aviation airport construction in China.

Guangzhou Baiyun International Airport is one of the important international aviation hubs of China's "Belt and Road" Initiative and the "Air Silk Road," and is also a core hub airport of the Guangdong-Hong Kong-Macao Greater Bay Area. The No. 2 and No. 3 underpass passage projects of the Phase III expansion project undertaken by the Tunnel Bureau adopt the shield tunneling method to pass beneath the airport's existing three runways and their taxiway systems, setting a precedent in the history of civil aviation construction.

The domestically produced large-diameter shield machine "Yunqing No. 1," launched this time, has a maximum excavation diameter of 11.76 meters and a total length of 120 meters, and passes beneath two runways and nine taxiways of Baiyun Airport. The overburden thickness throughout the section is 6 to 8 meters, less than one times the shield diameter, constituting ultra-shallow overburden shield tunneling construction; the geological conditions in the crossing area are complex, including unfavorable strata such as karst soil caves and mucky silty clay, and the section also passes beneath multiple important pipelines, with high settlement control requirements and great construction difficulty.

To avoid problems such as chamber clogging, segment uplift, and slag accumulation, the project team carried out targeted designs for the shield machine, including cutterhead stirring rod design, layered reverse-washing design of the circulation system, targeted design of the crusher, and grille design. Before launch, the project team held multiple problem-review meetings and invited academicians and experts to conduct thorough analysis and full demonstration of each risk point; the equipment was tracked and supervised throughout its manufacture at the factory, and an acceptance team was established to conduct acceptance inspection of the shield machine before delivery, minimizing safety risks during shield tunneling to the greatest extent and ensuring the smooth launch of the shield.

After the project is completed, Guangzhou Baiyun Airport will become the airport with the largest terminal building area and the most runways in China's civil aviation, and its passenger and cargo throughput scale will be in a leading position globally. It is of great significance for strengthening Guangzhou's international aviation hub and fully advancing the construction of the *** airport cluster in the Guangdong-Hong Kong-Macao Greater Bay Area.