On January 2, the "Tongzhou No. 7" shield tunneling machine successfully launched on the right line of the section from Heshan Road Station to Qingwei Road Station of Phase II of Qingdao Metro Line 7, constructed by China Construction Port and Waterway Bureau, marking that the He-Qing section of the project has officially entered the shield tunneling construction stage. This is also the sixth shield tunneling machine deployed in the Jimo section of Phase II of Line 7, marking that the construction of the Metro Line 7 project has entered a period of comprehensive acceleration.

It is understood that the "Tongzhou No. 7" shield tunneling machine launched from Qingwei Road Station and is tunneling along Mocheng Road toward Heshan Road Station. The right line of the section has a total length of 1,310 meters, a maximum gradient of 17‰, and a tunnel burial depth of 10.0 to 12.7 meters. During tunneling, it needs to pass through multiple risk areas such as a large building materials wholesale market and high-density residential areas. The tunnel body is mainly located in strongly to slightly weathered sandstone and argillaceous sandstone strata, with an average rock strength of 97.2 MPa. The launching end is located in a long-distance fractured zone, posing great construction difficulty and high technical requirements.

The shield tunneling person in charge of the Qingdao Metro Line 7 project of China Construction Port and Waterway Bureau, the contractor, introduced that the "Tongzhou No. 7" shield tunneling machine is a composite earth pressure balance shield machine, with a total length of 85 meters, a total weight of about 500 tons, an excavation diameter of 6.47 meters, an installed total power of about 1,965 kilowatts, a total thrust of 4,086 tons, and a designed maximum advancing speed of 80 millimeters per minute. "Tongzhou No. 7" unifies the data interfaces of all systems through the "Shield Cloud," uploads all data to the cloud, and has five major functions including "gas detection at the muck outlet," "automatic measurement of shield tail clearance," "muck weighing," "visualization of the soil chamber," and "visualization of the man lock," realizing information transmission throughout the tunneling process and all-round construction monitoring, thus facilitating smart metro construction.

Under the overall leadership of the Qingdao Municipal Public Utility Engineering Quality and Safety Supervision Station, Qingdao Metro Group and its Second Construction Branch, China Construction Port and Waterway Bureau planned ahead and actively deployed. In response to cross-operation and limited site conditions, it organized special meetings many times to discuss detailed issues, prepared special construction plans and emergency plans for shield hoisting in a targeted manner, refined target tasks, clarified responsibility division, conducted full-process side-station supervision and full-time monitoring and measurement, and successfully overcame many difficulties such as extreme low-temperature weather and operations under 110 kV high-voltage lines. It took only 15 days to complete the lowering, assembly, debugging and trial operation of the shield tunneling machine, and successfully passed the acceptance of the commencement conditions for the right line of the Heshan Road Station-Qingwei Road Station section and the key node of shield launching. The "Tongzhou No. 7" shield tunneling machine launched on schedule. After launching, the shield tunneling construction in the He-Qing section will be carried out by two work teams in 24-hour uninterrupted construction, and the shield tunneling machine is expected to tunnel 9 meters per day.

As a key breakthrough project in Jimo's urban renewal and urban construction, Phase II of Qingdao Metro Line 7 connects Qingdao's east coast urban area, Chengyang District on the north coast, and Jimo District, and is planned to open for operation by the end of 2026. After completion, it can strengthen the connection between Jimo and Qingdao's main urban area, realize rapid north-south connection of the urban areas, and is of great significance for Jimo to integrate into Qingdao and join the main urban area.