ISO INTERNATIONAL STANDARD 19904-1 Second edition 2019-05 Petroleum and natural gas industries Floating offshore structures - Part 1: Ship-shaped, semi-submersible, spar and shallow-draught cylindrical structures Industries du pétrole et du gaz naturel - Structures en mer flottantes- Partie 1: Unites monocoques, unités semi-submersibles et unités spars Reference number ISO 19904-1:2019(E) @ IS0 2019 IS0 19904-1:2019(E) COPYRIGHTPROTECTEDDOCUMENT @ IS0 2019 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either IsO at the address below or Iso's member body in the country of the requester. ISO copyright office CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +41 22 749 01 11 Fax: +4122 749 09 47 Email: [email protected] Website: www.iso.org Published in Switzerland i @ IS0 2019 - All rights reserved IS0 19904-1:2019(E) Contents Page Foreword .ix Introduction .xi 1 Scope. .1 2 Normative references .2 3 Terms and definitions .3 4 Symbols and abbreviated terms 11 4.1 Symbols 11 4.2 Abbreviated terms 12 5 Overall considerations 14 5.1 General 14 5.2 Safety requirements 14 5.3 Planning requirements 15 5.3.1 General. 15 5.3.2 Exposure level. 15 5.3.3 Basis of design. 15 5.3.4 Design practices 15 5.3.5 Inspection and maintenance philosophy 16 5.3.6 Documentation 16 5.3.7 Extreme weather preparedness. 16 5.3.8 Disconnectable floating platforms. 16 5.4 Additional standards and specifications 17 5.4.1 General. 17 5.4.2 Use for project application 17 5.5 General requirements. 17 5.5.1 Functional requirements 17 5.5.2 Structural design philosophy 18 5.5.3 Design criteria 19 5.5.4 Hydrostatic stability and compartmentation 19 5.5.5 Weight control. 19 5.5.6 Global response 19 5.5.7 Stationkeeping. 20 5.5.8 Materials 20 5.5.9 Topsides layout - safety considerations 20 5.6 Independent verification. 20 5.7 Analyticaltools 21 5.8 In-service inspection and maintenance 21 5.9 Assessment, re-use and life extension. 21 6 Basic design requirements .21 6.1 General 21 6.2 Limit states. 21 6.2.1 General. 21 6.2.2 Limit states for floating structures 22 6.3 Design situations. 22 6.3.1 General. 22 6.3.2 ULS situations 22 6.3.3 SLS situations. 22 6.3.4 FLS situations 23 6.3.5 ALS situations. 23 6.3.6 Temporary phases 23 7 Actions and action effects. .24 7.1 General 24 7.2 Permanent actions (G) .24 @ IS0 2019 - All rights reserved iii IS0 19904-1:2019(E) 7.3 Variable actions (Q) 24 7.4 Environmental actions (Ee) 25 7.4.1 General. 25 7.4.2 Environmental site-specific data 25 7.4.3 Wind actions. 26 7.4.4 Current actions. 28 7.4.5 Wave actions. 28 7.4.6 Vortex-induced vibrations and motions 31 7.4.7 Direct ice action. 32 7.4.8 Temperature effects 32 7.4.9 Tidal effects 33 7.4.10 Geotechnical hazards 33 7.5 Accidental actions (A) 33 7.5.1 General. 33 7.5.2 Collision 33 7.5.3 Dropped objects 34 7.5.4 Fire and blast. 34 7.6 Other actions.. 34 7.6.1 Stationkeeping actions 34 7.6.2 Sloshing actions. 34 7.7 Repetitive actions 35 7.8 Actioncombinations 35 8 Global analysis 35 8.1 General 35 8.2 Static and mean response analyses. 35 8.2.1 General. 35 8.2.2 Static equilibrium in still-water condition 36 8.2.3 Mean response analysis 36 8.3 Global dynamic behaviour 36 8.3.1 General. 36 8.3.2 Analysis models. 37 8.3.3 Mass.. 37 8.3.4 Damping. 38 8.3.5 Stiffness. 38 8.3.6 Action classification 38 8.3.7 Turret moored systems 38 8.4 Frequency domain analysis. 38 8.5 Time domain analysis 39 8.6 Uncoupled analysis. 39 8.7 Coupled analysis. 39 8.8 Resonant excitation and response 39 8.9 Platform offset. 40 8.10 Air gap and wave crest assessment. 40 8.10.1 Air gap 40 8.10.2 Wave crest effects. 40 8.11 Platform motions and accelerations 41 8.12 Modeltests 41 8.13