ABSTRACT
The twin-tube Lonato tunnel with its almost 5 km in length represents one of the most complex sections of the new High - Speed/High - Capacity Milan-Verona railway line, crossing the morainic formations of the Garda Lake and fluvioglacial deposits. The characteristics of the terrain to be bored, as well as the hydrogeological conditions, have also imposed the selection of peculiar technical characteristics for the TBM - EPB, including a high capacity to withstand the pressure at the face and consequently considerable thrust and torque. The main geotechnical and design challenges are related to the underpasses of the A4 motorway, with extremely reduced overburden. This paper will mainly focus on the experience of the TBM – EPB excavation of the first and second tubes, which were completed, respectively, in September 2022 and February 2024.
