A Soil TBM Based on Hydro-Excavation and Extruded Lining
There is plenty of room to enhance the current soil Tunnel Boring Machines (TBMs). The present article introduces a novel semi-mechanized tunneling method for soil excavation that uses high-pressure waterjets and concrete extrusion. Compared to conventional excavation tools (fracture, friction and wear), hydro-excavation has a higher power-to-weight ratio, faster advance rates and lower wearing of mechanical parts. Basically, the proposed equipment comprises a hollowed shield, with an internal movable system of waterjet nozzles and drain pipes. As the equipment advances forward, the soil inside the shield can be manually removed, reducing the operational cost. To complete, the proposed design provides an adequate support to the tunnel by filling the void at the rear end of the shield with extruded concrete as the shield moves forward. Due to its innovations, the proposed equipment offers a more cost-effective solution than current methods .