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Southern Expressway Duplication D&C

18.5 km of duplicated expressway on a complex brownfield site

Baulderstone Abigroup Joint Venture (BAJV), now Lend Lease Engineering

Adelaide, SA, Australia



Project Details

  • As lead consultant for the Baulderstone Abigroup Joint Venture (BAJV), KBR was responsible for the design and documentation of 18.5 km of duplicated expressway on this complex brownfield site.
  • KBR effectively managed the numerous integration issues involved in delivering a new asset immediately alongside an existing, operational asset. Working as part of a collaborative team with BAJV and other designers, KBR was a major contributor to the successful outcome of the project.
  • The lengthening of bridges over the expressway was a core focus during tender and detailed design. KBR and BAJV assessed multiple options to arrive at a solution that effectively balanced key considerations, including cost, constructability over and adjacent to an operational expressway, relocation of services, and minimized disruption.
  • In the chosen solution, existing road bridge spans were propped at one end, the abutment removed and the bridge lengthened. Delivery of the bridges along the corridor was sequenced to minimize disruption to the community. Single-span steel pedestrian bridges were removed and refurbished, and the span reused over the new carriageway, with a new span fabricated to cross the existing carriageway. In total, 20 bridges were extended or duplicated.
  • Over half a million cubic meters of surplus material was incorporated into landscaping along the route, creating recreation areas with walking and riding trails and 7 km of noise barrier walls. This prevented material being transported off site, thereby minimizing greenhouse gas emissions and disruption to the local community. In addition, rock blasted from the Darlington escarpment was also reused in the lower sub-base layers of the expressway in a further sustainability initiative.

Project Highlights

  • Significant reuse of surplus material enhanced environmental and community outcomes.
  • Existing steel pedestrian bridge spans were refurbished and reused in new positions.
  • Rock reclaimed from blasting works used as lower sub-base material after on-site crushing.
  • Earth mound and wall provision were optimized to minimize noise impacts.
  • Value engineering delivered efficient, constructible bridge lengthening and duplication and an innovative design solution to suit the client’s budget.
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