Bridges

The Main South Road and Victor Harbor Road duplication projects being delivered by the Fleurieu Connections Alliance, aim to provide safer and faster connectivity between Adelaide and the Fleurieu Peninsula whilst boosting the economic, social and urban growth opportunities of the Fleurieu Regional communities in South Australia. The bridge structures in the project are all located on the Main South Road alignment comprised of single span bridges over roadways and a multiple span bridge across a valley.

This paper will present the key technical design challenges, innovative and sustainable solutions of reducing whole of life costs while maintaining structural and functional integrity of the bridge structures. The key aspects that will be discussed in the paper are: the 5-span continuous bridge across the Pedler Creek valley with integral piers. The fixed articulation adopted at the piers has significantly improved the resistance of the structure against lateral loading, particularly during an earthquake event. Considering the height of the structure and access difficulty for future maintenance, the fixed piers allowed the elimination of bearings and expansion joints at these difficult access locations; the full integral bridge system adopted in the single span overpass and underpass bridge structures, where the use of projecting strands has been utilised to achieve positive moment connections.

Therefore reducing complexity and reinforcement congestion at the integral fender wall; sustainable solutions with the adoption of higher supplementary cementitious materials (SCM) of up to 65% on key structural concrete elements. Also the retention of the existing twin cell arched stonemasonry culvert constructed prior to 1929 to accommodate the additional road fill of the duplicated carriageways in lieu of a new structure.