Causeway Alliance

CATEGORY 4: Projects with a value greater than $50 million

Causeway safety innovations

Raising and widening almost five kilometres of causeway while keeping 90,000 motorists and 450 cyclists moving at all times every day through a narrow, complex and challenging site, is no mean feat. The massive, $220 million Causeway Upgrade Project is raising and widening 4.8 kilometres of Auckland’s Northwestern motorway (SH16) between Great North Road and the Whau River Bridge on the approach to Te Atatu. The contract period for the project is four years from February 2013 through to December 2016 in preparation for the opening of the Waterview Tunnels in early 2017. The target practical completion date is CATEGORY the third quarter of 2016. 4 FINALIST The contract is being managed by an alliance made up of the project owner (the NZ Transport Agency) and five design and contractor company participants – Fulton Hogan, CPB Contractors, AECOM, Coffey and Jacobs. Work is concentrated on a unique section of Auckland’s infrastructure, which was originally built in the 1950s, and has sunk by two metres and is prone to flooding. The project has a number of complex challenges and has required some unique responses to managing the consents, design and construction.

As the causeway runs beside a marine reserve managing or mitigating a number of environmental issues is crucial.

The geotechnical input of the project is very complex because of the variable, deep, weak subsoil including Jurassic-period greywacke from 200 million years ago, marine mud that is 25 million years of age, 30,000-year-old basalt from the Mt Albert lava flow, and a more recent shell bank.

“The project required construction to widen and raise the existing causeway by up to 2.5 metres adjacent to an existing operating highway carrying 90,000 vehicles daily over the past 3.5 years since work started,” say the alliance partners.

“Temporary traffic management has therefore been a critical item to manage for the success of the project. Added to this has been the construction of a new, shared path for cyclists and pedestrians with 450 daily commuters.”

Another project achievement says the alliance is its ‘Zero Harm’ safety innovations, which have been adopted on other projects. This is a legacy of which the project partners are particularly proud. l