The aim of this study is to try to establish new criteria for the design of offshore structures against extreme forces caused by breaking waves. The objective is to study shock forces and drag and inertia wave forces by means of several series of laboratory experiments and extensive field measurements. In a series of laboratory experiments dispersion properties of water waves are used to generate a non-steady situation where one wave train overtakes another resulting in the generation of an extreme wave. Collisions between wave solitons are studied in detail qualitatively and quantitatively, and results are obtained for characteristic wave properties: form, attenuation, dispersion, initiation and type of breaking, total pressure head and shock pressures. Results are also included for cases where currents are superimposed upon the mechanism for the generation of extreme waves. This deterministic approach in the laboratory will later be followed by extensive field measurements on a concrete gravity platform in the North Sea. Shock pressures near mean water level together with spectral and directional wave properties will be recoreded in the field. The laboratory experiments showed that three distinct types of breaking waves could be generated by wave-wave interaction in deep water, namely plunging breakers, deep water bores and spilling breakers. Field data on extreme waves obtained from wave rider buoys was analysed with the zero-downcross method which provided a wave height parameter relevant to the evaluation both of shock pressures and of the operation and stability of smaller vessels. Crest front steepness epsilon of the waves was used in the analysis as the total wave stepness s = H/L is not sufficient for asymmetric waves. The magnitude of shock pressures depends on the type and the wave form of the breaking waves.

  • Supplemental Notes:
    • Proceedings of the Eleventh Annual OTC held in Houston, Texas April 30-Ma6 3 1979, Volume 4.
  • Corporate Authors:

    Offshore Technology Conference

    6200 North Central Expressway
    Dallas, TX  United States  45206
  • Authors:
    • Kjeldsen, S P
    • Myrhaug, D
  • Publication Date: 1979

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00195808
  • Record Type: Publication
  • Source Agency: Offshore Technology Conference
  • Report/Paper Numbers: Volume 4 Proceeding
  • Files: TRIS
  • Created Date: Jul 31 1979 12:00AM