ABSTRACT
The data collected from the Aicha-Mules pilot tunnel were back-analyzed to assess the performances of the mechanized tunneling excavation and to evaluate the suitability of the chosen double-shield TBM adopted in the first Italian 10km of exploratory tunnel of the Brenner Base Tunnel (BBT) project. An extension of Rock Mass Excavability (RME) parameter to predict TBM advance is presented in the article in correlation with the “Average Rate of Advance (ARA)”. RME, in combination with ARA, was calibrated on the data obtained from the exploratory tunnel and showed good correlation with the rock quality daily recorded at the tunnel face in terms of RMR (Rock Mass Rating). A study was developed adapting the RME parameter to correlate rock quality data and advance rate, to understand if TBM performances were appropriate to the specific rock conditions and support decision making at next construction stages. A novel proposal, not based on RMR or Q, is finally presented on the basis of back-analyses.
