Geotechnical Innovations in the Tunnelling Industry

The Australian tunnelling industry has been thriving. In Sydney alone there have been 11 major projects in the past decade: the M2 widening, Metro Northwest, NorthConnex, Sydney Opera House forecourt, Wynyard Walk, City East Cable Tunnel, WestConnex (M4 East, New M5, M4-M5 link, Rozelle Interchange) and Sydney Metro. All this work within the same geological environment has enabled much innovation in terms of geotechnical and hydrogeological understanding, analysis of primary support, waterproofing, geological mapping and recording of observations during construction. This presentation documents some of these innovations and suggests where the industry may be going in the short to medium term.