Innovation Showcase | How Fugro framework helps reduce geotechnical uncertainty

Contractors preparing to submit tenders to build a €2bn (£1.71bn) deep stormwater pumping station in Qatar this summer may not realise how groundbreaking the geotechnical data they have to work with is.

Nonetheless, the client – the Public Works Authority Qatar – hopes that pioneering work by consultant Stantec and ground risk specialist Fugro means the bids will include less priced in risk and greater cost and programme certainty.

The project is one of the first to put Fugro’s Ground Risk Management Framework (GRMF) head to head with a conventional intrusive ground investigation to demonstrate the additional insights – and hence better-managed ground risk – that can be delivered.

Fugro solutions director for land site characterisation Rod Eddies describes the GRMF as being a “highly flexible solution incubator”.

“Internally the framework has been widely adopted, simply because it provides an engaging starting point for thinking about the challenges of our clients and their projects,” he explains. “It has allowed us to step back, think about the end goals of our clients, think about their engineering business objectives, think about the links between the stakeholders and how each of those are linked to then develop value-adding technical and commercial solutions.”

When it comes to how the framework works externally, Eddies explains that it has helped Fugro share and discuss the ground risk environment with clients and start better, earlier conversations about what the firm can do to reduce uncertainty and manage the ground risk.

According to Eddies, reports by consultant McKinsey & Co and the works of academics such as Bent Flyvbjerg show that major projects have the biggest risk of cost and programme overruns and that these are frequently related to ground risk.

“Clients are seeing a different perspective from us as a result of the framework,” explains Eddies. “They can see that we want to engage much earlier and explore imaginative solutions to manage this risk.”

The framework brings together a number of flexible solutions comprising “pick and mix” components relating to acquisition, analysis and advice. But it was the screening solution that proved to be particularly effective for the Qatar project although, less than ideally, it was not brought in right at the start of the work.

Clients are seeing a different perspective from us as a result of the framework. They can see that we want to engage much earlier and explore imaginative solutions to manage this risk

Stantec regional technical lead for ground engineering Andres Pinto, who is leading on the pre-design work on the deep pumping station for Public Works Authority Qatar, first came across the GRMF concept in 2020. Public Works Authority Qatar introduced Pinto to the new Framework Fugro had developed and Pinto wanted to pilot the approach.

He wanted to find out whether it was possible to produce an early 3D model using site screening and to gauge its impact on schedule and quality.

“Having experience of the conventional way of doing things in ground investigation and, knowing the challenges we faced on this scheme from experience on other projects in Qatar, my plan was to move away from the conventional and try to bring in more value,” explains Pinto.

An extensive geotechnical desk study of the site using 600 local borehole records was used to create a regional scale ground model. However, Pinto was still concerned about karstic features – voids formed by dissolution – within the limestone, due to the geomorphology of the site, particularly in the area where the deepest excavation was planned.

Based on the desk study, Stantec commissioned a conventional ground investigation involving 36 boreholes extending up to 80m in depth along with cross hole tomography within some of the boreholes and surface geophysics to try and understand the geology in 3D. Pinto says that this was time consuming and took more than six months to complete, plus the geophysics could only provide insights to 30m below ground level.

Early screening

In parallel, Stantec was also discussing with Fugro the use of early screening techniques from the framework approach, although that work started after the conventional investigation was completed.

“Ideally we would use the screening first to then guide the conventional ground investigation work,” says Pinto.

“But with the time it took to convince everyone to trial this approach, that was not possible.”

Public Works Authority Qatar started working on the contractor prequalification for the design and build contract after Fugro’s work was completed. “We wanted the contractors to be able to fully quantify and price the actual risk,” says Pinto.

Pinto describes Fugro’s approach as harvesting screening information through remote sensing. But he adds that the firm did not have access to the intrusive ground investigation results. This allowed Stantec to compare and contrast the conventional approach with the new.

“It was a true blind assessment,” he adds. “The results were good.”

Pinto asked Eddies’ team to focus on the main areas of concern and provide a full 3D shear wave velocity volume – to identify softer layers where there might be karstic features – to 80m depth for those areas.

Assessing critical areas

Fugro used 3D passive seismic techniques to assess the critical areas identified by Pinto. The site work to undertake the approach took around nine days and needed four weeks of analysis, but it did identify the problem areas accurately, proving that it was significantly quicker than the conventional methods.

Eddies says that this was possible because Fugro had a clear understanding of the objectives and was able to develop a more tailored screening solution to the site concerns.

He also believes that having this data ahead of the intrusive ground investigation could have accelerated that work by 50%, which may have allowed design or construction to start earlier.

Ultimately, the information provided by Fugro’s screening solution meant that Stantec was able to quickly confirm that competent rock was present for some of the deeper excavations.

“The screening gave us more information and, as a result, we could plan to reduce the risk,” says Pinto, who says he already plans to consider using the Fugro approach on a later phase of the project.

Geotechnical data acquired by both approaches for the site in Qatar will be used by tenderers which are due to submit bids by June 2023. Public Works Authority Qatar expects to award the contract by the end of the year.

The real benefits that could involve more effective risk transfer will come when the tender costs are known. Pinto adds: “It will be interesting to see how the risk is priced.”

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