Analysis of a Mechanized Excavation Using an EPB TBM The Case of the Grottaminarda Tunnel

This thesis presents an analysis of the main excavation data regarding the Grottaminarda tunnel, excavated using an EPB-TBM, almost in closed mode and under hyperbaric conditions. Chapter 2 will provide a brief introduction to the geological-geomechanical context of the area, in order to describe the main issues to be addressed throughout the section under investigation. Chapter 3 and Chapter 4 will present the predictive models used by the designers to determine the necessary machine parameters for excavation, and the P.A.T. (TBM Advancement Protocol). The latter is the "guideline" for the various work teams on site, essential for achieving proper progress in terms of pressures, thrust, torque, excavation volumes, and other machine-soil parameters. Monitoring will then be a central part of Chapter 4, as it is the main feedback and control tool for all phases of the project. In this chapter, I will present the main monitoring tool used on site: the Tunnelling Process Control (TPC) software from Tunnelsoft (Tunnelsoft). Chapter 5 will be focused on the main detailed analyses of the nine advancement sections examined. The entire analyzed path has been divided into nine time ranges, in accordance with what was established in the weekly excavation reports (Report, 2024). In each of these, the main tasks performed by the teams are presented, along with performance graphs regarding pressures and injection volumes, thrust, torque, and excavated material. Each graph will be followed by a brief comment and hypotheses. Finally, Chapter 6 will provide a comprehensive view of the entire excavation with a comparison of the data collected, including those on soil conditioning and therefore on FER and FIR. The consultation of the data was kindly provided by the Hirpinia AV Consortium, specifically authorized by the company Webuild S.p.A. (Webuild).