Density Meter in the tunneling industry
In slurry shield tunnel boring processes, the cutter head is filled with pressurized slurry (a suspension of bentonite or a clay and water mix) that applies hydrostatic pressure to the excavation face. The suspension penetrates the ground and forms the impregnated zone (coarse ground) or the impermeable bulkhead (fine ground), which causes the transfer of counter pressure to the excavation face.
The slurry also acts as a transport medium that carries the debris / soil to the slurry separation plant outside the tunnel. Accurate density measurement in the supply line as well as in the return line is of utmost importance during this hydraulic mucking process. The ADM is perfectly suitable for this application, as it works well with the continuous stream of abrasive materials; and it provides an accepted, sustainable, and non-hazardous solution in populated areas.