Chine development Tunnel Boring Machine technology for environment.
https://www.taylorfrancis.com/chapters/edit/10.1201/b16320-105/new-energy-saving-thrust-system-design-tunnel-boring-machine-wu-gong-peng-zhang-chen
https://www.taylorfrancis.com/chapters/edit/10.1201/b16320-105/new-energy-saving-thrust-system-design-tunnel-boring-machine-wu-gong-peng-zhang-chen
A new energy saving thrust system design for tunnel boring machine | Taylor & Francis Group
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