ABSTRACT
This paper presents a final analysis of the excavation of two parallel tunnels for the Metro of São Paulo Line 5 Expansion, which were excavated by two 6.9m EPB TBM. This current paper focuses on the stretch where mixed face conditions in Precambrian materials were excavated, which had high influence on the TBMs performance, such as difficulties in keeping a stable face pressure, ground losses (high settlements), sinkholes, slow advances, clogging, and very frequent and long hyperbaric interventions. The purpose of this document is to present a technical explanation for the events occurred in the excavations in this stretch, and for the impact in terms of production.
