Sydney Harbour Tunnel—Driven and Cut-and-Cover Tunnels

The paper describes the design and some construction aspects of the land tunnel approaches to the immersed tube crossing of the Sydney Harbour. Discussion is included on tunnel layout, excavation methods and order and method of working, primary and final ground support, concrete structures and filler wall construction. Durability aspects—i.e., groundwater, seepage, cocrete quality and membranes—are also presented. Monitoring results to date are also discussed.