Tunnel construction is nowadays highly mechanized. Securing work in mechanically driven tunnels through hard rock is mainly carried out with shotcrete. Sprayed concrete technology plays a central role for immediate support in the L1 zone as for permanent lining in the L2 zone. The different spraying systems must keep pace with the conditions set by the mechanical driving of the tunnel.
The problem created by the laser navigation system of an existing back-up train has been solved by the one-stage telescoping boom with offset-mounted spraying head. The manipulator is guided by two elliptic half arches, thus allowing interference-free laser positioning of the TBM, also during shotcreting.
The shotcrete spraying robot is a custom made designed system. The telescoping boom with 4m spray area and the spraying head are mounted on a carrier, able to travel around 260°. The spraying nozzle remains in the ideal position for easy shotcrete application.
Aliva pea gravel backfilling rotary machines conveying up to 10x more than conventional machines without changing the wear plates.