South African Institution of Civil Engineering (SAICE) Awards
– Winner: The Most Outstanding Project in Structural Engineering
The Siphofaneni Bridge is a 375 metre-long incrementally launched bridge over the Usutu River.
Bridge construction practices using incremental launching are used extensively worldwide. What distinguishes this bridge, is the use of reinforced concrete versus post tensioned concentric cables during the construction phase.
Conventional building methods use concentric cables to avoid the concrete cracking. This requires a specialist subcontractor coming to site weekly for several months to install and stress the concentric cables. While specialist contractors are easy to source near major centres, these skills are expensive and rare when working on remote sites. Aurecon used the approach of allowing the deck concrete to crack in the construction stages by using only reinforced concrete. Thereby only requiring the specialist subcontractor at the end of the deck construction phase. The final stage post-tensioning closed all cracks.