ABSTRACT
The Brenner Base Tunnel is mainly composed by two single track Railway Tunnels and an Exploratory Tunnel; Lot Mules 2–3 concerns a 22 km long stretch on the Italian side. It crosses the South part of mountainous dorsal between Austria and Italy, under overburdens up to 1850 m, consisting of rocks both of the Southalpine and Australpine domains, separated by the major Periadriatic Fault. The tunnels have to be carried out both with Mining and Mechanized (TBM) Methods, with average dimension ranging from 7 m (Exploratory Tunnel) to 20 m (Logistics Caverns). The forecasted rock mass behaviour varies from rock burst to squeezing phenomenon. The paper illustrates the risk management procedures planned at the design stage and the first experiences of their application: monitoring, surveys and tests during the advancement, guidelines for the application of excavation sections, design and operational risk identification, assessment & analysis, ownership, mitigation & control phases.
