On September 8, at the Qingbaijiang segment yard of the Chengdu-Chongqing Middle Line high-speed railway, as the last bucket of material was poured into the mold, the first segment for the Shu'an Tunnel, a controlling project of the Chengdu-Chongqing Middle Line, was successfully prefabricated. This marks that the segment prefabrication project for the earth pressure balance shield tunnel with the longest excavation distance and the largest diameter in China has officially entered the substantive production stage, providing important guarantees for the shield's launch on schedule and smooth advancement.

Qi Chun, head of tunnel design for the Chengdu-Chongqing Middle Line at China Railway Eryuan Engineering Group, introduced that the Shu'an Tunnel is located on the section between Jianzhou Station and Chengdu Station of the Chengdu-Chongqing Middle Line railway, with a total length of 10,380 meters. It is constructed using the "shield method + cut-and-cover method," of which the shield section is 9,824 meters long, making it the earth pressure balance shield tunnel with the longest excavation distance and the largest diameter in China at present. The entire tunnel has a total of 4,912 rings of segments, i.e., 49,120 segments, with a single segment weighing up to 14.1 tons. The segments for the entire tunnel are uniformly produced by China Railway 11th Bureau Group. To meet the schedule requirements of two shields constructing simultaneously, the segment production is designed with a daily capacity of 12 rings.

Wang Minghua, executive deputy manager of the Chengdu-Chongqing Middle Line Section 1 project of China Railway 11th Bureau Group, introduced that through independent research and development and the introduction of advanced domestic intelligent professional equipment and production management platforms, they have continuously improved quality and safety management assurance capabilities. Segment production adopts intelligent rebar processing production lines, intelligent segment flow production lines, and intelligent segment curing systems and other intelligent equipment and systems, and has been incorporated into the Smart-MES segment prefabrication production management platform to supervise the entire segment production process, achieving the effects of standardized management, visualized supervision, automated collection, digitalized information, and intelligent decision-making.

It is understood that since entering the site, the management team of China Railway 11th Bureau Group has successively overcome difficulties such as land acquisition, construction adjacent to operating railway lines, and construction of retaining structures for ultra-deep foundation pits. They have continuously strengthened communication and exchange with the construction unit, local government, and adjacent section units, reversed the construction schedule, and carried out construction with wall charts, smoothly completing the prefabrication of the first segment for the Shu'an Tunnel and laying a solid foundation for the official commissioning of the segment yard.