TBM Jiaoping No. 1, which was rolled out on May 29 at the company’s facility in Changsha, Hunan Province, will excavate what is expected to be the world’s largest-diameter EPB shield-driven tunnel for a high-speed railway.
The TBM’s diameter sets a new record for EPB-driven railway tunnels in China.
The machine has been customised to suit the geological conditions and construction requirements of the Mangshan Tunnel. Key design features include advanced earth pressure management, large-section excavation capability, and systems designed to maintain stable excavation performance while meeting stringent surface settlement limits.
For the tunnel’s long drive, the TBM incorporates an optimised cutterhead and tooling arrangement together with an integrated cutter wear monitoring system. To improve the machine’s performance in large-particle cobble strata, engineers have adopted a variable-opening cutterhead design intended to enhance spoil flow and excavation efficiency.
For settlement control the TBM is equipped with a multi-stage composite grouting system capable of both single-fluid and double-fluid injection, and an air-assisted excavation system for precise earth pressure management.
The machine also integrates synchronised thrust and segment erection functions, as well as intelligent control technologies including an AI-based TBM management platform and automated propulsion system.
The Jiaozuo–Pingdingshan Railway is a key part of China’s national “Eight Vertical and Eight Horizontal” high-speed railway network. Once completed, the Mangshan Tunnel will improve connectivity between north-west and south-western.
