Future-proofing New Zealand’s most critical bridge asset

Spanning Waitematā Harbour, Auckland Harbour Bridge is a landmark feature for Auckland and New Zealand. For 20+ years, we’ve been working with Waka Kotahi NZ Transport Agency on innovative structural upgrade designs to keep it safe for all to use.

As a critical piece of transport infrastructure, the Auckland Harbour Bridge (AHB) carries up to 200,000 vehicles a day, water supply pipelines, power and communications between central Auckland and North Shore City.

The bridge provided a much-needed link that unlocked the potential for Auckland’s expansion – transforming North Shore’s seaside villages and rural communities into thriving suburbs.

Today’s load demands on the bridge far exceed those of the original 1950s design, and over the years, a number of upgrades and maintenance works have been required to increase capacity, ease congestion and future-proof the bridge’s structural and seismic integrity.

In partnership with Waka Kotahi and the AHB Alliance, we’ve been involved with the long-term strategic planning and management of the bridge. Our civil structures team delivered a number of critical interventions using innovative approaches that attracted international interest – including a seismic and wind retrofit in 1999, the truss bridge strengthening in 2006 to cater for increasing traffic loading, and strengthening the extension bridges in 2010 for future traffic load growth.

The innovations which have extended the working life of the structure include implementation of bridge specific live loading derived from weigh-in-motion data from vehicles crossing the bridge, assessment and improvement of fatigue performance, and major strengthening works designed and implemented without impacting traffic flows on State Highway 1.

With further developments planned for the future, the Auckland Harbour Bridge will continue to connect the people of Auckland and meet the needs of the growing region.

Awards

• Auckland Harbour Bridge Seismic Assessment and Retrofit – ACENZ Award of Excellence (Gold), 2001
• Auckland Harbour Bridge Box Girder Strengthening, New Zealand Workplace Health and Safety Awards (Second Place), 2009
• Auckland Harbour Bridge Box Girder Strengthening, ACENZ Award of Excellence (Gold), 2011
• Auckland Harbour Bridge Box Girder Strengthening, Roading New Zealand Excellence Awards (Highly Commended), 2012
• NZPI Best Practice Award in strategic planning and guidance, 2015
• Arthur Mead <$10million Award – Auckland Harbour Bridge Alliance for Te Onewa Pā, 2018