During the design phase, soil investigations would identify soil types and groundwater pressures by location to allow for planning of adequate soil conditioners and TBM face pressures. Control of the amount of ground loss through the TBM face would be an important factor in controlling the ground surface and reduce the potential of ground surface settlement. Conditioning of excavated soil would help to control movement of material through the screw auger. The TBM operator would coordinate the TBM advance rate with the amount of material moving through the screw auger and onto the transfer conveyor.