"Tongzhou No. 7" Shield Tunneling Machine Successfully Launches (Source: Publicity Department of the Jimo District Party Committee)

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 Metro Line 7 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 driving 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.

According to the shield tunneling person in charge of the Qingdao Metro Line 7 project of China Construction Port and Waterway Bureau, the "Tongzhou No. 7" shield tunneling machine is a composite earth pressure balance shield tunneling 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" uploads all data to the cloud through the "Shield Cloud" unified data interfaces of various systems, 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, and helping to build a smart metro.

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, compiled targeted special construction plans and emergency plans for shield hoisting, refined target tasks, clarified responsibility division, and conducted full-process side-station supervision and full-time monitoring and measurement. It successfully overcame many difficulties such as extreme low-temperature weather and operations under 110 kV high-voltage lines, and completed the lowering, assembly, debugging and trial operation of the shield tunneling machine in only 15 days. It smoothly 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, and 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 advance 9 meters per day.

Next, the project team of China Construction Port and Waterway Bureau will combine digital shield tunneling technology, strictly control tunneling parameters, and continuously pay attention to the entire process of shield tunneling and segment assembly, so as to ensure controllable shield construction risks, accelerate progress while ensuring safety and quality, and continue to demonstrate new actions and new responsibilities in the journey of building "Qingdao on Rails."

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 connectivity of the urban area, and is of great significance for Jimo to integrate into Qingdao and rank among the main urban areas.