The latest demonstrator from startup hyperTunnel was built at the firm's R&D facility in the North Hampshire Downs.
The approach is claimed to be friendlier to the environment and will use sustainable materials such as low-carbon concrete. It could also drastically improve safety in the tunnelling sector because no humans need to enter the structure during construction.
A fleet of 'hyperBot' robots enters the ground via an arch of high-density plastic pipes and, once inside, can 3D print the tunnel shell by deploying construction material directly into the ground.
The 6m-long, 2m-high and 2m-wide Peak XV 'pedestrian-scale' tunnel has been delivered as part of a project for Network Rail.
The Network Rail project has been demonstrating the hyperTunnel process, investigating the technologies that are key to low-disruption tunnel repairs for the UK's regional railway infrastructure, which includes approximately 650 Victorian-age tunnels.
David Castlo, Network Technical head (Mining and Tunnels) at Network Rail, said: "Our large portfolio of Victorian tunnels requires increasing levels of work to meet the needs of the railway network. However, we want to reduce the level of disruption to our passengers so we are constantly searching for new approaches to enlarging or repairing tunnels that reduce the length of time a tunnel will be closed to trains. Peak XV moves us a step closer to that goal and, crucially, with a method that reduces workforce safety risk."
Steve Jordan, co-CEO and co-founder of hyperTunnel, said: "To unveil our first large-scale demonstration tunnel is a big step, not only for hyperTunnel, but for the tunnelling and construction industries which are eagerly anticipating the readiness of our approach to use, as appropriate, in their global projects.
"While using robots exclusively to build underground structures is dramatically different, the contributing technologies, such as digital twins, robotics, 3D printing and digital underground surveying, supported by AI and VR, are all well-proven in other industries. In fact, the hyperTunnel in-situ method is all about de-risking construction projects."
Earlier this year, hyperTunnel received funding of €1.88m from the European Innovation Council (EIC) Accelerator scheme.
In September, work started on a new tunnelling project in east London that will create a new route for cars, vans, lorries and buses to reduce congestion at the Blackwall Tunnel.
