Strong client relationships are much like any relationship. They are based on trust, communication, empathy and dependability to keep going strong. When it comes to client relationships, you also must be reassuring, accountable and continually exceed their expectations.
These attributes may contribute to the healthy long-term relationship WSP* has enjoyed with the Brisbane Airport Corporation for more than 35 years as it developed a world-class airport on a very challenging site. Such a long client-consultant relationship is rare and worthy of celebration, especially as a major milestone was reached with the opening of Brisbane’s new runway a few months ago.
Where it all began
Construction of a new, modern airport for Brisbane began in 1981 with the placement of 14 million m3 of dredged sand to reclaim the low-lying site at the mouth of the Brisbane River. Construction then started on the main runway, a shorter cross-runway, taxiways, and the domestic terminal. WSP* became involved around 1982, providing geotechnical investigations and advice on the domestic terminal’s foundations.
From then until now, WSP* has continued to support the extensive airport development through many different projects – small and large – as an environmental and geotechnical consultant. We’ve worked on runways, terminal buildings, an array of aeronautical facilities, as well as facilities outside the airfield including industrial, retail and sporting complexes.
Even in benign conditions, such multifaceted and extensive involvement is an achievement – but this site posed substantial complexities that kept us striving even harder and thriving on the challenges.
Overcoming challenges together
The Brisbane Airport site is in the region of the Brisbane River Delta. The soils in the delta are soft and waterlogged and continue to up to 35 m below the surface in some locations. Understanding the distribution of the levels of clay across the airport site has been an ongoing exercise as the team has gathered more and more geotechnical data since 1982.
These weak ground conditions posed a significant challenge to construction and required a large investment in ground treatment, such as surcharging to accelerate settlement. Even with this acceleration, the requirement for ground treatment to reduce long-term settlement of the weak ground posed a planning challenge for the Airport because of the sometimes long surcharging periods required.
The site also brought other challenges into play, such as naturally occurring acid sulfate soils which produce acid when exposed to oxygen when excavated from below the water table. This required active management of excavated soils and naturally acidic groundwater.
Another issue found on site was contamination from the historical use of firefighting foams which contained PFAS, a class of chemicals about which concerns are held regarding persistence, bioaccumulation, and environmental toxicity.
Getting to know each other (very well)
The team rose to these challenges throughout our ongoing activity during the development of the airport. Our priority was to capture our accumulated knowledge to better inform each new stage of work, which enabled our team to continually grow our knowledge base relating to ground conditions, material properties, and the performance of our designs. Over time, we’ve also developed a depth of understanding of our client’s business operations and priorities. A core team of WSP* specialists have collectively accumulated more than 60 years of experience of the airport site and its unique conditions.
As well as this extraordinary repository of human capital, we’ve developed GIS-based solutions, enabling our team to access a wide range of data from thousands of records (such as boreholes and cone penetrometer tests, settlement monitoring for surcharges, and groundwater monitoring) in the office and in the field via mobile devices. We developed innovative modelling tools to predict settlement behavior based on our knowledge of the properties of the soils on site, and from back-analysis of the data for surcharge treatments we’ve designed.
Making room to grow
A significant investment for the airport, and thus WSP*, was the new runway project. In 2005 we were engaged to perform preliminary design and environmental impact studies. Later, we developed detailed designs for surcharge and provided advice throughout various stages of construction.
A project of this physical size, with the variability in subsurface conditions that we already knew existed on the site, required an extensive site investigation. Variation in the thickness of the compressible clay sediments running through the runway site created the potential for varying amounts of settlement along the runway. The surcharge designs for the project had to accommodate these complex soil conditions with the aim of achieving a tolerable level of potential further settlement over decades of future operation, minimizing deterioration of the runway.
The project was challenging, involving reclamation of 3.6 km2, for which 11 million m3 of sand needed to be dredged from offshore and pumped onto the site. We monitored the settlement of the site at hundreds of locations and updated our settlement prediction models by calibrating them to the new data. This enabled us to verify the surcharge performance and to achieve a high level of confidence in our long-term predictions.
A successful journey
Throughout the years WSP* has been involved with the Brisbane Airport, our team has tackled complex challenges and applied our accumulated knowledge and technically sophisticated methods with the goal of delivering value for our client and innovative solutions that match their priorities. As we join our client in celebrating the opening of the new runway, we also celebrate the longevity of a relationship that began in 1982. We are proud that the Brisbane Airport Corporation chose WSP* as a travelling companion for the long haul.
About the Author
Scott Fidler is WSP*’s Regional Manager, Australia and New Zealand. He leads a team of nearly 1,000 people delivering engineering and environmental consulting services to clients across the transport infrastructure, mining, oil and gas, manufacturing, and government sectors. As a geotechnical engineer and hydrogeologist with over 30 years of experience, Scott is passionate about developing people, diversity and inclusion, sustainability and supporting local communities.
* This work was performed by Golder professionals who joined WSP in an acquisition completed in 2021.