The Role of Physical Modeling in Offshore Geotechnical Engineering with Edward Clukey

Abstract.

Physical model testing is an important part of offshore geotechnical engineering and has been used to verify foundation designs and provide important information for addressing new and challenging problems. Due to the loads and dimensions of many offshore geotechnical problems, it is often not possible to simulate prototype conditions; innovative approaches are then required to develop creative cost-effective solutions. Physical model testing, however, does not exist alone and ideally should be augmented by numerical modeling and field results. Numerical modeling can be calibrated to model tests and then used to perform sensitivity assessments of geotechnical and foundation data. Both types of modeling are complementary and when used appropriately can provide robust solutions to problems. The presentation presents results from physical model test programs investigating the following offshore geotechnical problems:

1) wave-seafloor interaction,
2) debris flow impact on pipelines,
3) behavior of suction caissons in clays and sands,
4) fatigue issues for conductors and steel catenary risers, and
5) the response of steel pile jackets and subsea manifolds/wells to earthquake induced ground motions.

The tests were performed under a variety of testing conditions, including 1g models, centrifuge models, foundation element modelling and fully coupled foundation-structure modelling. Some were small scale tests which did not match similitude scaling conditions while others were able to match many scaling relationships. All tests, however, provided important insights and advancements to the problems they addressed.
 

Bio. 

Edward C. Clukey earned his master’s and bachelor’s degrees from Worcester Polytechnic Institute and his doctorate from Cornell University. He is a registered professional engineer in California and Texas, a member of the Society of Underwater Technology, a Fellow in ASCE and a Diplomate (retired) in ASCE for both Geotechnical and Ocean Engineering. For almost 50 45 years, Dr. Clukey has focused on offshore geotechnical engineering. His research at Cornell and in the early part of his career addressed problems on wave-seafloor interaction. He was Geotechnical Advisor at BP America (1998-2015) and worked on deepwater foundations, geotechnical aspects of pipelines and risers, as well as earthquake and arctic engineering problems. Previously, he helped initiate the marine geotechnical program for the U. S. Geological Survey in California (1976-78) and prior to his BP experience worked for McClelland Engineers (1983-1985) and Exxon Production Research (1985-1998)). Since 1991, he has been actively involved with the development of suction caisson technology for deepwater applications. This work resulted in over ten publications on the topic and the installation of over 100 suction caissons throughout the world. He chaired the American Petroleum Institute’s (API) I task group which developed industry guidelines for geotechnical aspects of conductors, risers and pipelines, now currently in both in API and ISO design documents. Throughout his career he has championed the use of centrifuge model testing and advanced numerical models to address complex offshore geotechnical technical issues, managing ten centrifuge programs for problems related to ice gouging of the seafloor, suction caisson technology, piles capacity in Angolan soils, conductor and SCR fatigue, and the seismic response of offshore structures. Since his retirement from BP he has become an active committee member in COPRI developing a standard practice for renewable energy as well as a member of the ASCE Geo-Institute developing guidelines for the risk and reliability of geotechnical structures and foundations. In 2015 he started his own company GeoMaxEd. He has lectured at MIT ad Cornell and is the author of 55 technical publications. His experience covers many regions of the world, and he was selected to give the fifth McClelland lecture in 2022.