Southeast Asia Information Port News (www.dnyxxg.com) April 29th, at a depth of 105 meters underground in Yuanshan, Longgang District, Shenzhen, the "Pioneering Ox" tunnel boring machine (TBM), with a diameter of 14.31 meters and a length of 130 meters, successfully completed the precise docking of its trolley and main unit. This marks the completion of the assembly of the TBM for the Henggang section of the Longgang Tunnel on the Shenzhen-Shantou Railway, constructed and managed by Xiamen-Shenzhen Railway Guangdong Co., Ltd. and undertaken by China Railway 14th Bureau Group Co., Ltd.
This is the first large-diameter TBM in China to complete equipment assembly using the in-tunnel split-body air-push method. The Henggang section of the Longgang Tunnel on the Shenzhen-Shantou Railway is about to enter the tunnel boring stage.
The Shenzhen-Shantou Railway is an important component of the coastal corridor of the national "Eight Vertical and Eight Horizontal" high-speed rail network. The line starts at Xili Station in Shenzhen and ends at Shenshan Station in the Shenzhen-Shantou Cooperation Zone, with a total length of 125.486 kilometers and a designed speed of 350 kilometers per hour. The Henggang section of the Longgang Tunnel, constructed by China Railway 14th Bureau Group, is 10.307 kilometers long, with a 3,721-meter shield tunneling section. The "Pioneering Bull" shield tunneling machine used in construction required the integrated operation of the entire process—including assembly, air-pushing, launching, receiving, and dismantling—within a super-large cross-section tunnel. This is also the first large-diameter shield tunneling project in China to achieve this integrated operation within a single tunnel.
It is understood that due to the tunnel's location in the core area of Shenzhen's urban area, with dense buildings and heavy traffic, and its proximity to the Dongjiang River's secondary water source protection zone, traditional surface launching shafts were not feasible. Therefore, the project innovatively adopted a "sloping shaft transportation + in-tunnel assembly" technical solution. The Yuanshan inclined shaft was constructed for transporting shield machine components, and an assembly tunnel was built 100 meters underground to complete the entire process, including assembly, air-pushing, and launching—achieving a remarkable feat within a very limited space.
According to Cai Mingcong, the shield tunneling manager of the Longgang Tunnel Project of China Railway 14th Bureau Group, the Yuanshan inclined shaft is 743 meters long, with a maximum gradient of 10% and a minimum turning radius of only 80 meters. During transportation, the 250-ton super-large components, such as the cutterhead and main drive, are only 0.5 meters away from the inclined shaft structure; any slight bump could damage the equipment. Meanwhile, the assembly tunnel is 60 meters long and 16.55 meters wide, making it impossible to use large hoisting equipment. Operations such as turning the main drive and connecting the cutterhead are like building a giant dragon in a "matchbox." Furthermore, multiple processes, including the construction of the assembly tunnel, the excavation of the main tunnel and secondary lining, and the installation of hoisting equipment, are carried out simultaneously, making organization and coordination extremely difficult.
Faced with these numerous difficulties, the project team launched a systematic overhaul, collaborating with manufacturers to meticulously disassemble hundreds of components and customize special transport vehicles for different components. During the transportation of super-large components, two loaders with steel cable traction and auxiliary braking were used, and dedicated personnel were assigned to monitor the entire process, ultimately achieving zero damage and zero deviation in the delivery of all components into the tunnel.
With the completion of assembly inside the tunnel, the "Pioneering Bull" tunnel boring machine will undergo final pre-launch testing before entering the tunneling phase.
The Shenzhen-Shantou Railway, a high-speed passenger transport corridor connecting Shenzhen, Huizhou, and the Shenzhen-Shantou Special Cooperation Zone, will, upon completion, enable direct travel from Shenzhen's central urban area to the Shenzhen-Shantou Cooperation Zone in 30 minutes and cover the eastern Guangdong urban cluster within one hour. This will be of great significance for improving the regional high-speed rail network and promoting the integrated development of the Guangdong-Hong Kong-Macao Greater Bay Area. (End)
