Recently, as the cutterhead of the "Yuxing No. 1" shield machine slowly rotated, the right-line shield of the Shibati Station–Qixinggang Station section of the north extension project of Chongqing Rail Transit Line 18—constructed by Chongqing City Transportation Development & Investment Group Rail Group and undertaken by China Communications Construction—successfully launched. This is the second launch of the "Yuxing No. 1" shield machine following the completion of the breakthrough of the Qixinggang Station–Chongqing Station section, marking that the Shibati Station–Qixinggang Station section (hereinafter referred to as the "Shiqi section") has officially entered the shield construction stage!

The right line of the Shiqi section has a total length of 993.832 meters, of which the shield-driven section is 963.832 meters long. The minimum turning radius of the section is 350 meters, the maximum gradient is 44‰, and the burial depth is approximately 18.3 to 67.3 meters. At both ends of the section, 15-meter mined pass-through galleries are provided to enable the reception, translation, and empty pushing of the shield in the receiving (launching) shaft. At the same time, the receiving (launching) shaft can also serve as the civil air defense section of the station or the station-end wastewater pump room.

The "Yuxing No. 1" shield machine undertaking this excavation task is a composite earth pressure balance shield machine designed by China Communications Construction Group to fully adapt to Chongqing's geological and hydrological conditions. The shield machine features digital information processing and automated control of excavation parameters. Its cutterhead has an excavation diameter of 6.9 meters, the machine body is about 83 meters long in total, and its total weight reaches 684 tons. It is mainly electrically driven and can meet the requirements of excavation in complex strata.

To ensure the smooth launch of the shield, in view of the complex water conditions and surface and underground environments of the Shiqi section, the project construction team adopted a series of targeted improvement measures:

The project organized all relevant parties in advance to carry out a comprehensive inspection and acceptance of the shield machine, conducting checks at every stage—from cutter bolt tightening torque testing, non-destructive weld seam inspection, to pressure testing of pipeline and oil connections—to ensure the installation quality of the shield machine in all respects; sorted out the pre-launch work checklist and resource allocation, formulated special construction plans, and used two-dimensional drawings and three-dimensional modeling to conduct fitting analysis of the shield launch plan, ensuring the smooth reception, empty pushing, and launch of the shield machine at the mined station; arranged the processes carefully and compactly, orderly coordinated all construction operations, and carried out the main station construction and shield construction simultaneously in different zones, minimizing the impact of cross-operation between the main station construction and shield construction; systematically summarized shield construction experience, and in view of the weak points and risk points existing in shield excavation, organized all participating parties to hold construction seminars, concentrating efforts to overcome key and difficult points... Through the coordinated cooperation and concerted efforts of all participating personnel, the project safely and efficiently completed various key links such as the empty pushing, translation, installation and commissioning of the "Yuxing No. 1" shield machine, and the node acceptance before launch, successfully achieving the launch of the right-line shield of the Shiqi section.

At present, the themed labor competition is being carried out in full swing across the entire project line. All builders of the project will continue to seize the momentum and go all out to safely and efficiently complete the shield construction task of the Shiqi section.