Warringah Freeway Upgrade

Services Provided

Geotechnical proof engineering and Independent Check Engineer (ICE) for temporary works

Project Brief

FSG provided geotechnical support to ADG in the proof engineering and independent checking of a range of temporary works associated with the Warringah Freeway Upgrade (WFU).

The Warringah Freeway, immediately north of the Sydney Harbour Bridge, is one of the busiest and most complex road corridors in Australia, and involves the upgrade of several significant interchanges, untangling of traffic merges, addition of a dedicated busway and accommodation of tunnel portals for the Beaches link tunnel at the northern end, and Western Harbour tunnel at the southern end of the alignment.

Site Challenges

FSG has been involved in review and proof engineering of more than 20 different temporary works packages, ranging from relatively simple hardstands and working platforms, through to retaining walls and cuttings and several tunnel access shafts in varying ground conditions.  Each design package required works to be completed in tight conditions with a high level of complexity associated with geometry and site constraints, such as nearby utilities, live traffic or other physical constraints.  Reviews were required with often short turn-around times and required a good understanding of construction techniques deployed to ensure that designs were not overly conservative but remain safe and fit for purpose.  At the same time, the challenging geometry and congestion at some locations meant that FSG had to carefully review loading conditions and ensure an appropriate range of conditions are accounted for in each package.