Holmes has been providing ongoing professional engineering advice and support to CentrePort for more than a decade. The key skills we bring are typically in civil, structural, geotechnical, fire and construction engineering. We are regularly involved in activities that encompass new build, inspection and condition reporting, structural assessment, strengthening and refurbishment, public spaces, asset management planning and more. This experience has equipped us with an in-depth understanding of the working port environment and the ability to contribute our knowledge and expertise across all levels from high level planning through to providing technical advice and design to asset management.
Holmes, alongside Tonkin + Taylor, were engaged to deliver this programme of projects that included:
- Berth modifications to RFT2 & RFT3 to accommodate ferries
- Upgrades to Kings Wharf to maintain an important coastal shipping facility, and
- Post-quake temporary works to the Thorndon Container Wharf to resume operational continuity following the Kaikoura earthquake in 2016
- Wharf modifications to accommodate for Kaitaki and Aratere, including new linkspan, berthing, mooring, fenders and strengthening works
Working in close proximity to a major fault line had a significant impact on the designs. Seismic risk reduction was factored in to reduce impact in the event of an earthquake. The harsh marine environment demanded project-appropriate constructability, and a genuine understanding of engineering close to and beneath the ocean.
Te Awa walk and cycleway stretches along the Waikato River in central Aotearoa, running from Ngāruawāhia in the north to Karapiro in the south. The Perry Bridge was the final link in the chain, completing the path and opening up a fantastic activity for locals and visitors to the region. The original plans didn’t even include a bridge—but the client wasn’t able to secure permission to build the path on the west side of the river. The solution was a detour across to the east side of the river, by way of a new bridge, which was put out for competition.
Holmes and Emmetts Civil Construction submitted an alternative solution for the bridge involving a visually stunning, innovative network arch. The efficiency of this form of structure kept its costs within a practical budget, but the client also recognised the opportunity to create a visually compelling focal point to help attract people to the cycleway. Drawing on a concept conceived in the 1950s by the brilliant Norwegian engineer, Per Tveit, the project team delivered a visually stunning, innovative network arch bridge. The bridge is very long and thin, spanning 130m at just 3m in width—presenting a number of complex technical engineering challenges. It’s New Zealand’s fourth network arch bridge and the first of its kind in the country designed specifically for pedestrians and cyclists. It’s also the longest network arch bridge in the country.
Moving into the construction phase, it became evident that the proposed launch sequence, involving barges on the river, had a high level of risk and uncertainty. We devised an innovative and efficient alternative launch sequence, pulling the bridge across the river on cables. The launch went smoothly, and the outcome is exceptional. Our alternative tender design helped to capture the public’s imagination, and involved local schools, artists and other stakeholders to ensure relevance to the local community.
Holmes worked alongside contractor Heb to produce an alternative design for the Omāroro reservoir in 2019. This offering was ultimately successful, and the detailed design was completed for this critical Wellington Water project over the second half of 2020.
The Holmes structural and geotechnical design team created efficiencies through a number of means, saving the asset owner millions of dollars in capital expenditure. The alternative design drew on a thorough assessment of soil-structure interaction to demonstrate performance under service, ultimate and maximum credible earthquake events. This was particularly important for the reservoir as it is buried in its final state and a lifeline asset. We reduced material use and accommodated the contractors preferences by not adopting key elements of the original design.
We sought input from Wellington Water during the design process, and adapted aspects of the specification to suit their longer term needs. A simple example is the adoption of certain roughness requirements on the tank floor to reduce risk of slips for personnel inspecting or cleaning in future.
The team completed construction staging checks for precast walls and for different backfilling scenarios. Our structural modellers and civil designers performed a number of staged construction modelling exercises to assist the Heb team in communicating with their own staff and with external stakeholders. This enhanced safety outcomes and overall understanding for both project contributors and other interested parties.
With permanent works design complete, the team continues with temporary works, construction monitoring and technical support through 2021.
Auckland Airport has a number of expansion phases planned and underway on its International Terminal. The expansion of Pier B added two new gates (17 & 18), increasing the number of international aircraft using the airport. The 190-metre extension enables Pier B with the flexibility to accommodate a total of four A380 or eight smaller A320 aircraft at any time. In addition, the Pier B bus lounge was expanded from two boarding gates to four, to allow greater ability to board flights using aircraft located away from the terminal.
The project challenge for Holmes was the delivery of the construction phase in five stages, whilst maintaining the continuous operation of the airport for commuters and staff alike. Construction involved temporarily relocating the principal three main egress stairs for Pier B and then reinstating these into the permanent design. All of this needed to be undertaken without adding significant cost through temporary works.
Working with interim strategies is a frequent request of our clients, where we need to strategise closely with our project stakeholders, ensuring smooth transition of construction through to operation whilst meeting adequate safety requirements through the entire process. In doing this we take to time to understand the constraints and provide options to ensure the most workable solutions are adopted.
Using performance-based design solutions for the project provided a more efficient egress design including reduced construction costs for the client where we enabled the elimination of stairs that were part of previous fire strategies.
Feature New Zealand landscape artwork and sculpture is also incorporated to the design, welcoming guests to this area of the international terminal which has also been fitted out with a new retail store and food and beverage outlet. Feature ceilings provided challenges to our fire protection design to ensure that sprinklers were installed to operate effectively, and without compromising the aesthetics.