Australian Research Council Centre of Excellence Geotechnical Science and Engineering

Mr Colm O’Beirne

Research Interests

  • Anchoring systems
  • Offshore geotechnics
  • Physical modelling

Supervisors

  • Associate Professor Conleth O’Loughlin
  • Professor Christophe Gaudin

Research Topic

Geotechnical performance of dynamically installed anchors in soft clay

Research Abstract

As the development of oil and gas field exploitation moves into deeper waters, the industry is tending towards cost effective anchoring systems as an alternative foundation solution. A dynamically installed anchor is torpedo shaped and following release from a designated height above the seabed (typically 20 – 50m) it reaches a maximum velocity of 25 – 35m/s and penetrates by up to 3 times the anchor length by the kinetic energy obtained through free-fall and anchor self-weight.

The project investigates the geotechnical performance of such anchors in normally consolidated clay; the dominant deep-water seabed deposit. Basic issues of predicting anchor embedment depth and subsequent holding capacity for given anchor geometries, anchor drop heights and seabed strength profiles are addressed. The development of a comprehensive experimental database is envisaged following completion of an extensive suite of reduced scale field tests and centrifuge experiments employing model anchors.

Why my research is important

Considering the scarcity of experimental data from field trials and model tests, and given the potential economic benefit of dynamically installed anchors to industry, there exists a clear need for an investigational study to be conducted. The development of a comprehensive experimental database will have considerable merit in the improvement of design charts and verification of numerical/analytical techniques that predict the embedment and eventual capacity of dynamic anchors under working and ultimate loading conditions.

The essential issues of predicting anchor embedment depth and subsequent holding capacity for a given anchor geometry, anchor drop height and seabed strength profile will ultimately lead to increased industry confidence.

Funding

  • SIRF
  • UIS
  • COFS ad hoc scholarship