News from Foshan, Guangdong – On April 26, China's first demonstration project of 3D-printed integrated tunnel lining constructed by China Railway No.3 Engineering Group passed on-site inspection and acceptance at No.1 Transverse Tunnel of Xiangqian Tunnel on the Guangzhou-Zhanjiang High-speed Railway, marking a key leap for China's construction 3D printing technology from ground to underground applications and from conventional to complex environments.
The 3D-printed integrated tunnel lining structure adopts high-toughness fiber concrete materials for spray 3D printing. Through multi-stage homogeneous dispersion, multi-frequency vibration, anti-sagging and mechanical toughness evaluation, as well as impermeability and crack resistance optimization, the design and optimization of high-performance fiber concrete materials are realized. The graded concrete structure boasts excellent toughness and waterproof performance, forming a new type of tunnel lining structure integrating design, construction, support and waterproofing. The technology fundamentally breaks through the long-standing bottlenecks of traditional processes such as poor adaptability to extreme environments, high operation risks and limited structural integrity, and significantly improves the design flexibility, construction intelligence and structural integrity of tunnel linings.
The success of this project not only provides a replicable and promotable intelligent construction model for non-cast-in-place tunnel construction nationwide, but also promotes the systematic transformation of tunnel construction mode from experience-dependent to intelligent control type through the innovative integration of new technologies, new materials, new methods and new structural systems. It lays a solid technical foundation for supporting the implementation of the transportation power strategy and making China's tunnel construction technology rank among the world's leading level.
