ANALYSIS OF DYNAMIC TRANSIENT RESPONSE (RINGING) IN A GRAVITY-BASE STRUCTURE

The Troll Gravity Base Structure (GBS) to be installed in 1995 will be located in about 300m water depth. The natural periods of the structure in surge and sway are of the order of 5-5 one half seconds. Model tests carried out showed that greater responses than expected from "classic" design practice were likely under steep wave conditions. Recent model tests on other structures have also shown that loads on large diameter surface piercing cylinder in steep wave conditions are considerably larger than those expected from classic design practice. In irregular waves, this has contributed to a dynamic transient response, a phenomenon commonly referred to as "ringing". The challenge was to explain the physics behind these additional loads and quantify these to such a degree that structural reinforcement carried out on the Troll GTBS for this specific reason during construction could be justified. This paper describes the work that was performed to verify the integrity of the Troll FBS in the in- place conditions focusing upon the resolution of the above.

  • Supplemental Notes:
    • OTC 94, 26th Annual Offshore Technology Conf; 2-5 May 1994; Houston, Tx, USA. Procs. Vol 2, ppr 7464, p 455 [12 p, 17 ref, 3 tab, 16 fig]
  • Authors:
    • Ahilan, R V
    • Klaas, M
    • Langen, I
  • Publication Date: 1994

Language

  • English

Subject/Index Terms

Filing Info

  • Accession Number: 00716167
  • Record Type: Publication
  • Source Agency: British Maritime Technology
  • Files: TRIS
  • Created Date: Feb 28 1996 12:00AM