Building protection for the inner city tunnel excavation for the Metro in Rome / Bauwerksschutz für den innerstädtischen Tunnelbau am Beispiel der Metro in Rom

For the construction of the Metro B1 line in Rome, special settlement reduction measures were implemented for settlement-sensitive structures beside deep excavations with depths of up to 45 m. These measures were necessary due to the excavation of tunnels with 6.8 and 9.8 m diameter under challenging soil and groundwater conditions. The originally designed jet grouting bodies were replaced by compensation grouting. This enabled all works to be performed from eight shafts (maximum 24 m depth), limiting the public space requirement. The efficiency of compensation grouting was demonstrated in two full-scale field trials and the advantages of active settlement compensation were proved during tunnel excavation.