The Barwon Heads Road Duplication is being duplicated between Barwarre Road and Marshalltown Road. The project-wide capital budget is $365M and the project is being delivered in three (3) work packages. Once complete, the duplication will improve traffic flow and safety in the area, and provide access to active and public transport modes. AECOM has been engaged by BMD Constructions to deliver the detailed design of Work Package 2. The key features of this work package include:
- Construction of a new bridge over the rail line at Marshall and removal of the existing level crossing
- Duplication of 1.1 km of Barwon Heads Road two lanes to four lanes
- A new shared use path along the alignment and on road cycle lane
- Ground improvements and reinforced earth retaining wall
- Associated civil infrastructure including drainage, pavements, performance level barriers signage and linemarking and road furniture.
Engaged by BMD, AECOM improved upon the concrete super T bridge documented in the reference design by developing a three-span steel bridge, presenting significant cost and time-saving opportunities for BMD, reducing disruption to the public and providing a safer road and rail environment earlier than previously thought possible.
Outcomes and Value
Key improvements AECOM contributed to include:
- Three span steel bridge structure solution presenting cost savings to BMD / MRPV ($15M). In addition, the three-span steep bridge solution reduced the extent of reinforce earth wall required, and created additional storage area for flood management, and access for maintenance vehicles within the rail corridor.
- The controlled modulus columns (CMC) ground improvement solution has enabled the reinforced earth structure to be built above the shallow groundwater table, and has also supported achieving the strict settlement and horizontal movement tolerances.
- Adjustment to the geometry to facilitate offline construction of Barwon Heads Road, reinforced earth walls and steel bridge structure. In addition, the geometry was adjusted to enable the reinforce earth blocks to be constructed in one phase.
- Optimisation of the CMC layout and design compared to the TOC design, despite the poorer material encountered during supplementary ground investigations, presenting cost savings to BMD.
- Optimisation of the geometric design to reduce the extents of retaining wall required by about 500m.
- Design and implementation of a rail berm solution accepted by Stakeholders in lieu of a deflection wall, presenting cost and time saving BMD.
- Minor adjustments to the existing boom gate accepted by Stakeholders for the temporary case, saving a new boom gate installation during construction.
- Use of existing road pavement for proposed V/Line maintenance laydown areas in the western and southern quadrant, provided a reduction in required materials and construction works.