Bringing geotechnical engineering to the surface

Engineering was never on the cards for Professor Susan Gourvenec FREng when she was younger, growing up in a suburb just north of London. “My dad was an accountant, and I wanted to be an accountant,” she says.

But she showed her ingenuity and flair for problem-solving from an early age. “I was always interested in how things worked,” she says. “I liked making things as a kid, especially to make something fit for purpose, if it wasn’t how I wanted it.”

Although she had never considered her childhood tinkering as an interest in science and engineering, “and I don’t think my parents or teachers did”, she found her way to civil engineering. She studied at undergraduate level at Queen Mary University of London, topping her class, before specialising in geotechnical engineering and getting her PhD at her current home of the University of Southampton.

“I was a bit of an accidental engineer, and I’m immensely grateful for that turn of fate,” she says. “This is one reason why I’m passionate about outreach and public engagement.” Indeed, with just a third of young people saying they “know a fair amount about what engineers do”, and only half of teachers saying they feel confident advising students on pathways into engineering, the profession may remain invisible to a countless number of potential engineering stars.

Shifting perspectives

After more than a decade working with the oil and gas industry in Australia, developing innovative design methods for foundations and anchors to secure offshore infrastructure in deep waters and challenging seabeds, Gourvenec began to question whether her knowledge and skills would be better applied to advancing renewable energy. “I had genuinely believed we were doing something important, providing energy and energy security, by developing design solutions for safe and reliable infrastructure,” she says.

But as the reality and urgency of climate change became clearer, she started taking a different perspective. She found herself with a tough decision to make: stay in her exciting and challenging career in oil and gas, where she had built up a great track record, or begin her transition to renewables, which meant a change of continent.

So, when the opportunity to return to Europe and work in renewables arrived in 2017, she took it. “It was a career risk,” she says. “At the time, quite a few people thought I was mad.”

Today, it’s fair to say she made the right decision. In 2019 Gourvenec became a Royal Academy of Engineering Chair in Emerging Technologies, leading the Centre of Excellence for Intelligent and Resilient Ocean Engineering (IROE). Her centre develops responsible and resilient solutions for harnessing energy from offshore windfarms, and her research guides policy on how we should use oceans in the future.

Second wind

Gourvenec is Professor of Offshore Geotechnical Engineering, and Deputy Director of the multidisciplinary Southampton Marine & Maritime Institute at the University of Southampton. “I’m a geotechnical engineer, so I deal with engineering challenges that involve the ground; soil and rocks,” she says [see ‘What is a geotechnical engineer?’]. In her current role she applies her geotechnical engineering expertise to address big renewables problems, including where we should put the wind turbines we need to reach our climate changes, and how can we ensure they last their entire lifecycle?

The UK has an ambitious and urgent renewable energy target. We’re aiming to reaching 50 gigawatts of offshore wind by 2030, from about 14 gigawatts today, to generate enough renewable energy to supply millions of UK homes and businesses with green electricity and reduce our carbon emissions on a pathway to net zero by 2050.

The target means we’re going to need more wind turbines. A lot more wind turbines. We know that taking them offshore is the way to go – more wind blows out at sea, and we can build the turbines bigger to generate even more electricity. But there are various challenges we need to solve to reach these offshore targets.

One challenge is working out where best to build them. Many sectors use the ocean – “We identified 37 different ocean sectors in a recent piece of research,” Gourvenec says – and it’s important to ensure that wind farm sites, along with other ocean activities, are planned to balance environmental and societal needs.

Another key challenge is the seabed itself – it’s not an easy place to build. Not only is it highly variable, with soils ranging from fine clays to large boulders, it is a dynamic environment – constantly under the influence of ocean currents. Also, the seabed properties change over time. When you install a foundation or anchor for a wind turbine, the loads imparted on the soil around it alter the engineering properties of the soil, which in turn affects the response of the foundation or anchor to the future loads.

Gourvenec and her research team at the University of Southampton develop theoretical methods to capture this evolution of soil properties through the life of infrastructure. This is so that they can develop foundation and anchoring systems for wind turbines that will stand firm for a generation, but not be wastefully overdesigned. It’s also important that these structures can be decommissioned safely, with minimal disruption to marine life and minimal lifecycle use of resources.

Along with her team at Southampton, she’s pioneering novel design philosophies and methods, developing solutions that can be rolled out around the world.

A day in the lab

Gourvenec and her team work at the National Infrastructure Laboratory, based at the University of Southampton, a facility with state-of-the art geotechnical and structures labs that was established recently as part of the UKCRIC Collaboratorium, a multidisciplinary network of UK universities connecting research with policy and practice in infrastructure and urban systems.

When we meet (online), Gourvenec has just come out of a meeting with a PhD student to work through some comments on a journal paper, and a research meeting with a postdoc before that. She has a relaxed, but enthusiastic, energy, and seems happiest when discussing her research teams’ work.

She tells me about the geomechanics lab and geotechnical centrifuge facility. Researchers test elements of soil and models of soil-structure interaction to work out how different parts of the seabed, or different foundations and anchors – otherwise invisible to us – will behave under a range of stress conditions and over the duration of their operating life.

The facility is fitted with a geotechnical centrifuge six metres in diameter. “Like the one in the Bond movie Moonraker, if you know it!” The centrifuge simulates prototype-scale stress levels with small-scale models.

Researchers load the soil samples and scaled-down models of the turbine foundations into a “strong box” about the size of a small fridge, which represents an area of seabed the size of a football pitch, and a depth of more than 60 metres. When the centrifuge spins into action, the sample is subjected to forces of up to 130G – 130 times Earth’s gravity.

“The centrifuge can also ‘speed up time’, because of the scaling relationships that control the response of soils in centrifuge conditions. This means that a 25-year operating life can be modelled in a day,” Gourvenec explains. “You can observe the response of the ground and the structure, whether or not the soil will densify or loosen, and at what point, if ever, the trend will stabilise, and how this affects the response of the system.” The method lets engineers simulate the conditions that structures experience over the duration of their life in a controlled and instrumented environment. This provides performance data that is impractical to obtain at full scale and over real operating periods, allowing new design methods to be validated.

Many of the team focus on computational work using numerical models, often in combination with AI approaches, to simulate soil-structure interaction problems. The experimental and computational work complement each other. Gourvenec’s team also faces the challenge of characterising those ever-changing conditions of the seabed. “[We use] computational and AI techniques... in conjunction with extant data, to derive reliable geotechnical engineering parameters from seismo-acoustic data,” she says. “Such a step-change in offshore site characterisation is essential to achieve the pace and scale of offshore wind deployment needed to meet net zero targets.”

Gourvenec and her team work closely with experts in many different disciplines including ship science, robotics, acoustics, geoscience, marine science, computer science, law and policy, and archaeology. “Ocean activities and our impacts on ocean health cross many disciplines,” she says. She works with many partners, in both industry and government, to ensure her team’s research is “informed by need”, and that their solutions can be practically deployed.

To tomorrow's engineers

Solving global problems calls for people with a wide range of skillsets and expertise. Just as an insight from one area of research can solve a problem in another, someone with an outside perspective can shake you out of your current ways of thinking and bring a new perspective.

While she was a professor at the University of Western Australia, it took an interviewer conducting an equality, diversity and inclusion (EDI) survey to show Gourvenec things could be different.

“Of these people you started with: one’s your boss and one’s director of their own centre. Why aren’t you in such a role?” the interviewer asked Gourvenec, then in her 10th year at the university. “Well, they’re probably better than me,” Gourvenec answered. That had to be it, right? “No, no, no…”

After this meeting, diving into the EDI literature, and reading up on how decades of unconscious or conscious bias can manifest in inequalities in society, it occurred to her that perhaps it wasn’t that her peers were better than her, and that “there was probably more at play”.

The meeting set her on a course that would change her career. “Just becoming aware of this made me seek out a deeper understanding, rooted in the evidence in the literature, as well as seeking out an EDI-aware community and allies,” she says.

By 2015 she had become the Chair of the inaugural ED&I committee at the University of Western Australia’s engineering faculty. “There had never been an EDI committee,” she says. After arriving at the University of Southampton in 2017, she became Chair of the engineering faculty’s EDI committee.

While EDI has improved since her start in engineering, there is still a lot of work to be done. Gourvenec notes the difference between “highlighting pockets of good practice”, and “making meaningful and pervasive cultural change”. The former may win an institution brownie points, but doesn’t do much in the long run.

“The engineering profession – and society – is still on that journey,” she says. “In my own group and network, I champion EDI through building confidence and awareness, ensuring everyone’s voice is heard, mentoring and sponsoring individuals, and creating a culture of inclusion.”

So, how do we get more diverse voices in the field? “Give under- and unrepresented voices a platform and opportunity to be heard, and value a diverse range of skills and perspectives” she says. “The Academy does a good job of this – giving people a platform to shine, doing what they are great at.”

A look back

Gourvenec’s list of achievements is long, although is there anything she’s particularly proud of that isn’t on her CV? “The achievements of people I have worked with or taught,” she says, referring to the undergrads she sees doing well in their grad schemes, and the PhD students and early career researchers developing their careers in academia or industry. “Without taking anything away from what they have achieved themselves, I am very proud to have been part of their experience.”

She also describes having a family – Gourvenec lives with her husband and two teenage children – as an achievement she’s particularly proud of. “In the 21st century, that should not be such an achievement, but having a family and a career is still made too hard for too many people.”

To those who are interested in engineering as a career, she advises following your interests: “There are so many types of engineering, there will be something that captures your interest and imagination and that you are good at,” she says – and encourages people to take a look at #thisisengineering to reveal the diversity of job opportunities and pathways.