In the heart of Wellington, New Zealand lies the Pukeahu National War Memorial Park and the Arras Tunnel, the Government’s centrepiece for First World War commemorations, a place of national significance.
As part of the Memorial Park Alliance, we were tasked with the complex engineering and construction challenges of delivering this project in a highly urban environment.
Through strong client leadership, a collaborative delivery model, and innovative design, the Alliance delivered the Arras Tunnel a month ahead of schedule and the park in time for the 25 April 2015 ANZAC centennial. The result: a lasting legacy that united partners behind a shared national vision.
Integrated infrastructure services
As a key partner in the Memorial Park Alliance, we delivered a wide range of services including:
- Stakeholder Engagement
A critical component of the project involved permanently relocating State Highway 1 into the newly constructed Arras Tunnel, enabling space for this place of national significance above it.
Design and Engineering Solutions
As part of the Alliance, we addressed technical and environmental challenges through innovative solutions:
- Fire life safety: A tailored fire life safety risk assessment ensured fire response systems and resistance were built into the tunnel.
- Seismic resilience: The Arras Tunnel was designed to withstand earthquake events, a critical requirement given Wellington’s high seismicity.
- Custom belled-out tension piles: These were used to ensure structural stability under the effects of large seismic-induced soil pressures.
- Ground water regime: Temporary ground water re-charge wells were designed to maintain the existing ground water conditions and protectheritage buildings. A granular mat was used in the tunnel base to preserve the water table.
- Stormwater and wastewater: A 200m pipe-pull was used for stormwater drainage from the tunnel. The tunnel’s vertical alignment and construction ensured the existing 120-year-old brick egg-shaped strategic sewer could remain in operation throughout the tunnel construction.
Collaborative approach to problem-solving
As part of the Alliance, we worked collaboratively with New Zealand Transport Agency Waka Kotahi, Ministry for Culture and Heritage and Mana Whenua to address project challenges, including:
- Complex design requirements
- Protection of heritage infrastructure
- Addressing stakeholder concerns including residents, school communities, and business owners
- Protection of the local ecosystem and compliance with environmental regulation
Delivered on time, designed to endure
- Delivered ahead of schedule: The Arras Tunnel opened in September 2014, one month early, and the Park was completed for ANZAC Day on 25 April 2015.
- Enhanced urban design: The Pukeahu National War Memorial Park is symbolically landscaped with architectural tunnel portals, creating a memorial that commemorates international relationships.
- Stakeholder satisfaction: An independent survey showed 86% satisfaction among directly affected stakeholders.
- Legacy of trust: Our success as a project team led to additional projects, including:
- Seismic and systems upgrades to the Mount Victoria SH1 tunnel
- Marine wharf upgrades in the Chatham Islands
- Streetscape and road safety enhancements on Victoria Street
Delivering a better world
This landmark project demonstrates our capability to deliver complex transportation infrastructure projects. The Arras Tunnel provides essential transport connectivity, and Pukeahu National War Memorial Park serves as a meaningful national memorial.