ABSTRACT
When crossing squeezing rock masses the risk of overstressing the lining is always relevant. In case of mechanized excavation with shield TMBs one of the possible countermeasure is the use of compressible filling for the annular gap. This paper presents the application of the expanded clay as filling material for the construction of the main tunnels in the sector of the Trens emergency stop of the Brenner Base Tunnel which will be constructed with mechanized excavation using a double shield TBM. The emergency stop is located in a particularly complex geomechanical context, characterized by the presence of fault zones and squeezing rock masses.
