Numerical modelling of liquefaction around marine structures

Direction Prof. Dr.-Ing. habil. Nils Goseberg
  Dr. Christian Windt
Team Dr. Christian Windt
Funding Federal Ministry for Economic Affairs and Energy (Bundesministerium für Wirtschaft und Energie,BMWi)
The Scientific and Technological Research Council of Turkey (TÜBIKTAK)
The National Centre for Research and Development in Poland (NCBR)
Duration 09/2020 - 09/2023
Project partners Großmann Ingenieur Consult (GICON) (GICON)
  WIKKI Consultancy and Software development in Computational Continuum Mechanics (WIKKI)
  BM SUMER Consultancy & Research (BMSUMER)
  Institute of Hydro-Engineering of Polish Academy of Sciences (IBW)
  Projmors Designing Office For Maritime Structures Company Limited (PROJMORS)

Brief description

Enhanced understanding of the response of seabed underneath marine structures is essential for more efficient exploitation of marine resources, both economically and in terms of environmental impact. Seabed liquefaction is  the phenomenon by which it can temporarily act as a liquid under certain conditions. Liquefaction can cause catastrophic failure of marine structures (e.g. sinking of foundations, floatation of buried pipelines) as well as excessive displacement of marine structures (e.g. stepwise failure under breaking wave impact). Therefore, accurate and efficient numerical models of wave-seabed and wave-structure-seabed interaction are necessary for optimum development of marine infrastructure. The NuLIMAS project aims at developing an open-source numerical modelling framework for liquefaction around marine structures, which can reproduce the most salient physical processes with a reliable level of accuracy. For this purpose, several physical model experiments are planned to isolate the basic mechanisms of seabed liquefaction and fill knowledge gaps needed for the development of an accurate predictive numerical toolbox. NuLIMAS will also build upon earlier experiences and efforts to investigate seabed liquefaction on national as well as transnational levels. The project consortium includes partners on the forefront of scientific and technological developments in seabed liquefaction. The developed numerical model will be calibrated and validated using the planned idealised physical model tests. Moreover, the applicability of the numerical model to realistic conditions will be examined by reproducing large-scale physical model tests of a general-purpose floating  marine platform with a gravity anchor. The numerical model as well as the results of all physical tests will be documented and published online for future use by interested professionals. The numerical model will assist the development of simplified models for preliminary use in practical applications.

General objectives:

The NuLIMAS project aims at developing an accurate virtual laboratory of Fluid-Structure-Soil Interaction (FSSI) for marine structures. FSSI is the consideration of the close coupling  etween the hydrodynamic, structural and geotechnical processes on the behavior of marine structures and foundations. This virtual lab will:

  • Reduce probability of liquefaction failures to minimize related human and economic losses and reduce insurance costs
  • Increase service life of marine structures and reduce their construction costs
  • Reduce risk, design uncertainty and safety margins
  • Eliminate the necessity for extensive physical model testing or the use of oversimplified methods for geotechnical design