Bridges

Jacobs worked for McConnell Dowell - Decmil Joint Venture consortium and Major Road Projects Victoria to design the Mordialloc Bypass. The 9km long freeway connects the Mornington Peninsula Freeway to the Dingley Bypass, improving connectivity in Melbourne's south-east. It comprises a four-lane carriageway, and the design allows for a future project upgrade to a six-lane freeway within the current footprint and layout of bridge structures. The Bypass opened to traffic in November 2021. Jacobs carried out the civil and structural design. The author managed the design and provided construction phase support for the portal and cantilevered traffic sign structures, retaining walls, off-structure and bridge barriers, noise walls and Super-T girder bridges. The project includes eight major structures: Landfill Structure, bridges over Old, Centre and Lower Dandenong Roads, Governor and Springvale Roads and approximately 330m long twin viaducts crossing the wetlands between Springvale and Governor Roads.

It is one of the first projects in Victoria with civil structures designed to AS 5100-2017 and associated VicRoads Bridge Technical Notes (BTNs). The paper covers aspects of the design and construction for selected structures and challenges associated with site conditions, existing utilities, design requirements and construction program. The design development and construction phase support resolved unfavourable soil conditions, predicted settlements and piling issues within the old landfill site, and avoided relocation of existing services such as pressurised gas and oil pipes and sewer mains at Old Dandenong Road and wetland viaducts. It also covers the design of the portal and cantilevered traffic sign gantries and supporting structures attached to bridges using circular hollow sections to comply with the latest Vicroads BTN fatigue requirements. The Mordialloc Freeway Project has been named a finalist for the 2022 Australian Construction Achievement Award, illustrating the exceptional ingenuity and standards of excellence in this project.