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Event Organiser: The British Geotechnical Association

Geotechnique Lecture: Designing infrastructure for an evolving seabed, London

  • Lecture
  • London
  • 21 November 2019
  • 18:00 - 19:40
Geotechnique Lecture: Designing infrastructure for an evolving seabed, London

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Offshore infrastructure is an essential element of our energy system and our communication networks. This infrastructure rests on a seabed that evolves with time – due to environmental processes, and due to the action of the infrastructure itself. The design of cables, pipelines, foundations and anchoring systems is made complex by the evolution in soil properties caused by the whole-life loading history – from installation, through in-service loads, to the end-of-life solution. In addition, ocean-seabed-infrastructure interaction can cause sediment transport and scour, altering the seabed geometry and causing changes in embedment and support.

This Geotechnique lecture tackles the geotechnical challenge of designing infrastructure for an evolving seabed, examining ‘whole-life’ changes in seabed strength and geometry.

Changes in soft soil strength arise from both monotonic dead loads and cyclic live loads. Examples for pipelines, foundations and anchors will be shown, drawn from centrifuge model tests, numerical simulations and field data. Significant changes in strength by a factor of 2-3 are typically evident. These effects matter most at shallow depths, close to the seafloor. New types of element test and penetrometer will be shown, which target this near-surface strength.

Meanwhile, in both coarse-grained and fine-grained soils, excitation from the ocean or the infrastructure can lead to sediment transport, scour and subsidence. These effects are often, but not always, detrimental to design. Examples of this fluid-structure-seabed interaction are described, from the laboratory and the field.

The lecture will close by showing how these whole-life effects can be harnessed through innovative technologies, such as:

  • New types of robotic penetrometer test that simulate whole life effects
  • Foundations that deliberately slide across the seafloor
  • Anchoring systems that rely on whole-life changes in strength

Modern numerical techniques, such as finite element limit analysis, now provide definitive solutions for the stability and bearing capacity of structures, if the geometry and strength of the surrounding soil are known. The examples in this lecture highlight the remaining uncertainties for offshore infrastructure, which are the changing soil properties and geometry.

The event will be followed by a drinks reception which has been sponsored by COWI.

Please note: This event will be broadcast online – the link will follow.

COWI

Programme

18:00 - Registration and refreshments
18:30 - Welcome from the Chair
18:35 - Main lecture
19:15 - Questions and answers session
19:35 - Summation from the Chair
19:40 - Finish
19.45 - Drinks in the Café Bar – sponsored by COWI

Speakers

Professor Kevin Higgins

Chair

Professor Kevin Higgins

Kelvin graduated from the University of Birmingham and joined Sir Alexander Gibb & Partners (now part of Jacobs). He worked for Gibb in the UK and overseas (Oman & Falkland Islands) and completed a MSc at Imperial College. He then joined the Geotechnical Consulting Group where he became a Senior Partner specialising in the application of numerical methods to geotechnical problems and the control of construction to limit the impact of construction on infrastructure. He is a Visiting Professor at Imperial College.

Professor David White

University of Southampton

Professor David White

David White is Professor of Infrastructure Geotechnics at the University of Southampton, based at the UKCRIC National Infrastructure Laboratory. He completed MEng and PhD degrees at the University of Cambridge then remained in Cambridge as a Research Fellow and then University Lecturer. In 2007 he was appointed Professor at the University of Western Australia in Perth, holding an ARC Future Fellowship (2009-2012) and then the Shell Chair of Offshore Engineering (2013-2017).

His research is primarily concerned with offshore energy facilities, ranging across cable, pipeline, foundation and anchoring systems as well as soil characterisation. He collaborates across disciplines with experts in fluid mechanics, sediment transport and fixed and floating structures, exploring the challenges of coupled problems. The real work has been done by a cohort of 25 PhD students that he has supervised, and many talented post-doctoral researchers. He has been an investigator in research projects supported by the EPSRC, ARC and the EU, with parallel support provided by industry operators, contractors and consultants.

During his PhD he co-developed an image analysis system for deformation measurement in geotechnical testing. The latest freeware incarnation of this technology – GeoPIV-RG – continues to grow in popularity for applications across civil engineering.

He was the Founding Director of the ARC Research Hub for Offshore Floating Facilities (offshorehub.edu.au) and is now a Co-Director of the EPSRC Supergen Offshore Renewable Energy Hub (supergen-ore.net). He is active in engineering practice, consulting for the offshore industry to support the transfer of research into practice, and he has been elected a Fellow of the ICE, the Royal Academy of Engineering and the Royal Institution of Naval Architects.

His research has led to >300 publications, which have received 9 best paper awards, including the BGA Award three times. He has authored 45 contributions to Geotechnique over the past 17 years, with the most recent publications forming the basis of the 2019 Geotechnique Lecture.

Event venue

Institution of Civil Engineers
One Great George Street
Westminster
London
London SW1P 3AA
United Kingdom

For more information please contact:

Gabriella Lai

e: [email protected]

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