Pipe Jacking Microtunneling Machine / Mechanical Moles For Drilling

TBM s (Tunnel Boring Machines), commonly called “mechanical moles”, or, more technically, full-section mechanical cutters, have revolutionized the approach to tunnel construction, providing a precise and efficient mechanized solution compared to any other traditional method of digging based on manual labor. TBMs are complex and versatile machines capable not only of drilling, but also, thanks to an integrated system, of disposing of the debris generated by the excavation process and, depending on the conditions and needs, also to simultaneously assembly the precast tunnel segments.

Key Features and Components: 

In the front part of each Tunnel Boring Machine there is a sophisticated rotating head (cutterhead), also called milling head, connected behind the very important main bearing which ensures the rotation and application of the longitudinal thrust. The front of the rotating head houses a series of cutting tools (rippers, scrapers and disc cutters) designed according to the composition and geomechanical characteristics of the front to be faced. In the design of the rotating heads of TBM intended for predominantly rocky terrain, the choice of materials for the realization of disc cutters, plays a crucial role in the effectiveness and performance of the machines themselves. In particular, steel is one of the most used materials in the production of cutters for its characteristics of strength, hardness and machinability.

Another essential factor for TBM cutting tools is their geometry, understood as the angle of inclination and configuration of the tip (or the profile, in the case of rotating discs), which must be optimized to adapt to the characteristics of soils of various nature (rocky, compact or fractured, sandy, etc.). 

Product Parameters:

Tunnel Boring Machine: Perspectives and future challenges:

Despite several positive features of the current Tunnel Boring Machines, they still have ample room for improvement. The start-up and maintenance costs, for example, are still high, requiring highly qualified personnel to manage operations.

The current researches and studies bode positively for the future. Among other things, high capability and “Green TBMs” are being studied, which will further reduce the construction time of the tunnels allowing to realize even particularly complex projects in relatively short periods.

In summary, one can conceivably imagine that the next developments of the Tunnel Boring Machine will not only transform the way underground infrastructure is built, but also that will contribute to positively shaping the future of urban mobility, resource management and environmental sustainability.