Engineers Australia

Tunnelling to and Under Airports

Ted Nye

The design and construction of tunnels and other underground structures at airports is perhaps more complex than usual because of the need to interact with airport operations on airside. The presentation will give some background to past rail tunnel and station construction at Sydney Airport and on the approaches to the airport. The ground conditions are principally deep soft fill and alluvium deposits overlying sandstone rock. Since its completion in 2000, major building works have occurred adjacent and over these underground structures both at the Domestic and International Terminal stations.

Heathrow Airport is the busiest airport in the world with a labyrinth of tunnels beneath it to service road, rail, baggage, utility services and pedestrian travel functions excavated principally in London Clay. The completion of Terminal 5 in 2008 was a milestone in the airport’s development where nearly a fifth of the budget went underground.

The presentation will describe some of the technical challenges during the design and construction of the Sydney, Airport Line, and which could be similar to those envisaged for Perth’s proposed airport link, including recent building developments adjacent and over the stations and tunnels at the two passenger terminals. An overview of the more recent tunnel work at Heathrow Airport will also be given.


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