On June 5, the ultra-large diameter slurry shield tunnel boring machine (TBM) “Greater Bay Area Xili” (CREC No. 1616), jointly developed by China Railway Tunnel Group and China Railway Engineering Equipment Group, a subsidiary of China Railway Hi-Tech Industry, both under CREC, rolled off the production line in Shunde, Guangdong Province. The machine will soon be deployed for the construction of the new Shenzhen Xili Railway Station and related works, contributing to the development of a major transportation hub in the Guangdong-Hong Kong-Macao Greater Bay Area.

The new Shenzhen Xili Railway Station and related works constitute a key node project within China’s national “Eight Vertical and Eight Horizontal” high-speed railway network. Among them, the Xili Tunnel is a critical component for connecting the station with surrounding transportation networks and ensuring its overall functionality. The shield-driven section of the tunnel is approximately 4 kilometers long, with a maximum burial depth of 75.8 meters. The alignment passes through strata including weathered granite of varying strengths and multiple deeply weathered troughs, presenting highly complex geological conditions. The tunnel also passes beneath 21 major structures and facilities, including railways, highways, and metro lines, imposing extremely demanding requirements on the TBM’s pressure control and settlement management capabilities.

To address challenges such as long-distance hard rock excavation, passage through fault fracture zones, and high-pressure groundwater conditions, the “Greater Bay Area Xili” TBM was specifically developed for the project. The machine features a cutterhead diameter of 13.9 meters, an overall length of 135 meters, and a total weight of approximately 3,750 tonnes. The development team equipped the TBM with multiple specialized technologies, including a composite cutterhead with closely spaced cutters and a large opening ratio designed for atmospheric-pressure operation, a direct-discharge screw conveyor system capable of handling high pressure, and a zero-discharge system. In addition, the machine is equipped with innovative technologies such as an intelligent cutter wear monitoring system and a new multidimensional visualization system, significantly enhancing its level of intelligent operation.

The new Shenzhen Xili Railway Station and related works are planned as one of Shenzhen’s five primary and five secondary railway passenger transportation hubs. The station will integrate four high-speed railway lines—Ganzhou–Shenzhen, Shenzhen–Maoming, Shenzhen–Shanwei, and Shenzhen–Zhuhai—along with multiple intercity railways and urban rail transit lines. Upon completion, the project will create a multi-tiered rail transit network comprising “4 high-speed railways + 2 intercity railways + 4 metro lines,” making it the largest high-speed railway station and rail transit interchange hub in Shenzhen. The project will be of great significance in supporting Shenzhen’s development as a national railway hub city and strengthening the core engine role of the Guangdong-Hong Kong-Macao Greater Bay Area.