Laboratory Tests for EPB Tunnelling in Rock Masses. Feasibility Study

The EPBS (Earth Pressure Balance Shield) tunnelling is widely used when is necessary to avoid surface settlements by controlling face stability and the underground water income. A growing field of application of this technology is in rock masses where polluting materials are present, or when it is necessary to work with a full bulk chamber to prevent exploding gasses to come inside the tunnel. In fact the particular operative procedure of EPB technology, using the machine in “closed mode”, can avoid the dispersion of the dangerous materials in the underground environment. The presented research has been carried out in order to evaluate the possibility to use the EPB technology in rock masses with an effective tunneling process in terms of soil conditioning, conditioned soil permeability, pressure transmission on the tunnel face and possibility to extract the material with screw conveyor, and the obtained results are described and discussed.