Conclusions of Workshop
Date and Place:
January 14-15, 2020 at Kongens Lyngby, Denmark. The workshop was held at COWI
Motivation and Scope:
Much research on the topic of ship collision risk and ship impact loads was initiated at the time of the Great Belt project in Denmark, as summarized in “Ship Collision Analysis”, Proceedings of the International Symposium on Advances in Ship Collision Analysis, Copenhagen, Denmark, 1998. Since then published research has been less systemized into a coherent body of knowledge and it seems to be appropriate now to attempt to establish the present status.
Current practice on the assessment of ship collision risk generally relates to either AASHTO Guide Specification and Commentary for Vessel Collision Design of Highway Bridges or Eurocode 1991-1-7 combined with appropriate collision frequency modelling. However, design according to AASHTO and Eurocode generally leads to quite different results even though the base foundation is as such the same.
In the light of the coming Eurocode update, the workshop took the opportunity of addressing some of the important issues and point to needed improvements to obtain a consistent approach throughout the industry. In the longer perspective the aim was to achieve a consistent assessment framework that can fit into Eurocodes and be a guide to the practitioners.
Therefore, by the means of this workshop we brought together experts in this field and assembled novel research and practical expertise with respect to ship collision risk and ship impact loads to structures, such as bridges, quays or offshore structures. The following topics were covered:
- Frequency modelling.
- “Heinrich ratio”, i.e. the probability of no structural failure despite of a nominal exceedance of the structural resistance (due to incomplete force or energy transfer).
- Ship-structure interaction (bow, sideways and deckhouse collisions)
- Codified design framework (global loads, local loads, eccentricities and impact angles).
- Definition of failure / operational limits
- Failure and impact statistics
- Acceptance criteria
- Case studies