Adelaide's South Road Superway

Abstract

The A$825 million (£428 million) South Road Superway project will deliver a 4·8 km long expressway standard corridor from Adelaide's Port River Expressway to Regency Road and is part of a larger programme to upgrade the whole of South Road to a high-standard, high-speed arterial link. The project features a 2·8 km long elevated roadway carrying up to eight lanes of traffic above the existing South Road. The brief for the project required the elevated roadway to have a 9 m clearance under the superstructure, minimum spans of 50 m and to provide a high standard of landscape and urban design finish. The elevated roadway viaduct consists of a match cast segmental superstructure constructed by the balanced cantilever method with multiple variations in segment cross-section to cater for the complex geometry of the alignment. Superstructure spans range from 50 m to 83 m and are constructed monolithically with elegant Y-shaped piers. Deck articulation is provided by mid-span steel needle beam expansion joints, which eliminate the requirement for large bearings under the deck. This paper provides an overview of the design and construction of the viaduct, focusing on features of both the architecture and construction methodology that led to unique design challenges.