Geotechnical engineers need to seek out alternative solutions to meet the foundation demands of the next generation of offshore wind farms, according to Oxford University head of engineering science and professor of civil engineering Guy Houlsby.
Houlsby proposed that screw piles could provide the solution in place of monopiles and suction caissons as wind farms start to be developed in deeper water during his Rankine Lecture which was delivered to a packed lecture theatre at Imperial College, London on 19 March.
The Interaction of foundations in offshore design lecture also looked at the difference between offshore solutions used by the oil and gas industry and those needed by wind farms and how probabilistic analysis can verify bearing capacity theory. Houlsby also said that engineers should make greater use plasticity theory to communicate geotechnical issues in the offshore environment with structural engineers.
Houlsby concluded the lecture by looking at the potential screw piles offer to the offshore foundations market. “They are robust and simple,” he said. “However, scaling up existing screw piles by a factor of three or four presents a challenge and a contractor needs to develop the equipment to install them – essentially we need the world’s biggest screwdriver.”
At the end of the event, British Geotechnical Association chairman Chris Menkiti announced that the 55th Rankine Lecture will be delivered by Norwegian Geotechnical Institute technical director Suzanne Lacasse. Lacasse is the first woman to be honoured as a Rankine Lecturer and will deliver her lecture in March 2015.