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Difficult Ground Solutions


Difficult Ground Solutions (DGS)

Keep Your TBM on the Move.

Every technological breakthrough Robbins has ever made has been an answer to one of our client’s challenges, and our latest offering is no different. Difficult Ground Solutions (DGS) is a suite of options available for shielded hard rock and Crossover TBMs that can keep your machine moving in long tunnels, high cover, and challenging geological features. From Continuous Advance Shield Design to Water Inrush Control, Robbins is committed to keeping your project moving forward.

Enhanced probe drilling with two drills (multiple trajectories shown in red and orange).


DGS is about visualization: A machine shield doesn’t have to obstruct your view of the ground around you. With a host of features like 360-degree, long distance probe drilling, convergence measuring sensors that alert operators to squeezing ground, and canopy drills for ground consolidation, you can stay a stroke ahead of your TBM operation.


A host of DGS features can keep your TBM boring in even the most challenging geology. Multi-speed gearboxes, known as the Robbins Torque-Shift System, help prevent your machine from getting stuck by giving you the flexibility to excavate at high RPM/low torque in hard rock or low RPM/high torque when moving through difficult ground. Continuous Advance Shield Design further ensures that your machine will get through the most difficult ground. Features like stepped shields and lubrication ports are customized to move through squeezing ground and blocky rock. If your machine does encounter a sticky situation, breakout torque and emergency thrust options have been proven to get machines moving again.

Hydraulic shield lubrication ports pump Bentonite into the annular gap between machine shield and excavated material.


In the event of a massive water inflow, Water Inrush Control lets you seal off your TBM and create a safe working environment while dewatering and consolidating ground. Sealable muck chutes and multiple rows of main bearing seals can effectively hold back water pressures up to 30 bar. For Double Shield TBMs, inflatable seals can close the gap between machine shields and keep your crew safe.

Water Inrush Control is capable of sealing your TBM against water pressures up to 30 bar or more.