Doc.No : UPD-BC-G4-CS-DR-6003 DESIGN OF JACKET STRAND JACK SUPPORT Doc. Class : Discipline : Error! Unknown Revision : D1 Document type: Contractor Job No : 365 System/Subsystem : document property name. Rev. Date : Contract No : 4600006595 Page 1 of 17 UJUNG PANGKAH DEVELOPMENT OFFSHORE PHASE II HESS (INDONESIA-PANGKAH) LTD (WHP-B EPCC) Strandjack Bracket Design For Jacket and Topside D1 A Rev. 22-July-09 18-May-09 Date Issued For Approval Issued for Review Description DBES DBES By HKM HKM Check MARK MARK App By Date Company Approval Contractor Approval Doc. No : UPD-BC-G4-CS-DR-6003 DESIGN OF JACKET STRAND JACK SUPPORT Doc. Class : Discipline : Error! Unknown Revision : D1 Document type: Contractor Job No : 365 System/Subsystem : document property name. Rev. Date : Contract No : 4600006595 Page 2 of 17 TABULATION OF REVISED PAGES SHEET 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 B1 X X X X X X X X X X X X X X X X x REVISIONS SHEET REVISIONS Doc. No : UPD-BC-G4-CS-DR-6003 DESIGN OF JACKET STRAND JACK SUPPORT Doc. Class : Discipline : Error! Unknown Revision : D1 Document type: Contractor Job No : 365 System/Subsystem : document property name. Rev. Date : Contract No : 4600006595 Page 3 of 17 TABLE OF CONTENTS CHAPTER 1.0 2.0 3.0 4.0 5.0 6.0 INTRODUCTION SCOPE OF WORK DESIGN SPECIFICATION DESIGN APPROACH DESIGN OF STRAND JACK SUPPORT MANUAL DESIGN VERIFICATION PAGE 4 4 4 5 6 11 APPENDICES APPENDIX – A STRAND JACK SPECIFICATION APPENDIX – B WEIGHT CONTROL SUMMARY & ESTIMATION OF REQUIRED PULL FORCE APPENDIX – C STRAND JACK SUPPORT DRAWINGS APPENDIX – D FEM INPUT & OUTPUT FILES Doc. No : UPD-BC-G4-CS-DR-6003 DESIGN OF JACKET STRAND JACK SUPPORT Doc. Class : Discipline : Error! Unknown Revision : D1 Document type: Contractor Job No : 365 System/Subsystem : document property name. Rev. Date : Contract No : 4600006595 Page 4 of 17 1.0 INTRODUCTION This document presents the analysis and structural design of strand jack support for loading out WHP-B Jacket Structure at Bakrie Fabrication Yard. The WHP-B Jacket Structure will be skidded out from its fabrication position onto the transportation barge using hydraulic strand jack system. These strand jacks will be mounted on the existing skid frame temporary support structures that support the entire weight of the WHP-B Jacket Structure. For typical strand jack specification and details, refer to Appendix – A. 2.0 SCOPE OF WORK Design checks are limited to global and local strength of the strand jack support and its attachments where the strand jack supports are to be mounted and maximum pull forces are supported. Detailed skid frame, tie back system and jacket member structural integrity strength checks are beyond the scope of this report. 3.0 DESIGN SPECIFICATION (1) API RP 2A 21st Edition – Recommended Practice fo Planning, Designing and Constructing Fixed Offshore Platforms (WSD) by American Petroleum Institute (2) AISC Manual of Steel Construction (Allowable Stress Design) – by American Institute of Steel Construction Generally, increases in basic allowable stresses ARE NOT allowed for load out condition. The following basic and combined allowable stressed criteria are adopted (Fy is material yield strength): Axial Tension, Fat Axial Compression, Fac Bending Stress, Fby Shear Stress, Fv Von Mises Stress, Fvm = 0.60Fy = Max 0.60Fy = 0.66Fy = 0.40Fy = 0.80Fy for combined axial, bending and shear stresses Doc. No : UPD-BC-G4-CS-DR-6003 DESIGN OF JACKET STRAND JACK SUPPORT Doc. Class : Discipline : Error! Unknown Revision : D1 Document type: Contractor Job No : 365 System/Subsystem : document property name. Rev. Date : Contract No : 4600006595 Page 5 of 17 4.0 DESIGN APPROACH (a) Strand Jack Support Arrangement The Strand Jack Support System are to be arranged in such the manner that the induced forces due to skidding operation will be adequately transferred to the existing temporary support structures and skid frame system. (b) Design Loadings / Assumptions The following design loadings are considered: Weight Control Report No: Factored Weight UPD-BC-W2-WC-RP-0002, Rev 3 = 403.7MT Assumed vertical static load on support can = 73MT per leg Assumed coefficient of friction = 20% during initial skidding stage, Nos of Strand jack, N Estimated pull force per jack = 2 Nos = 43.4MT / jack (Refer to Appendix – B for Weight Control Summary & Estimation of Required Pull Capacity) (c) Analysis and Design Methodology Analysis and design are performed using SAP2000 Finite Element Software (FEM) and verified by manual calculation. (d) Materials All plate materials shall be of ASTM 36 (Min. Yield Strength = 248MPa) or equivalent, unless specified otherwise. All welding shall comply with AWS1.1 and shall be of full penetration welds, unless specified otherwise. Doc. No : UPD-BC-G4-CS-DR-6003 DESIGN OF JACKET STRAND JACK SUPPORT Doc. Class : Discipline : Error! Unknown Revision : D1 Document type: Contractor Job No : 365 System/Subsystem : document property name. Rev. Date : Contract No : 4600006595 Page 6 of 17 5.0 DESIGN OF STRAND JACK SUPPORT 5.1 GENERAL ARRANGEMENT The Strand Jack Support System are to be arranged in such the manner that the induced forces due to skidding operation will be adequately transferred to the existing temporary support structures and skid frame system. It shall be ensured that the all the strands are clash-free with jacket or other temporary structures. For detail strand jack support drawings, refer to Appendix – C. SAP2000 Ver.10 software is used for structural modelling and analysis of the strand jack support system. The temporary support can and strand jack supports are modelled as finite element (shell element) with appropriate restraint conditions (fixed-supported). The following presents the isometric view of the simplified structural model of strand jack support system: Temporary Support Can Dia1181x32thk Strand Jack Support (Typ) Top FLG/Ring Plate PL25 Exist'g Bottom FLG/Ring PL25 Doc. No : UPD-BC-G4-CS-DR-6003 DESIGN OF JACKET STRAND JACK SUPPORT Doc. Class : Discipline : Error! Unknown Revision : D1 Document type: Contractor Job No : 365 System/Subsystem : document property name. Rev. Date : Contract No : 4600006595 Page 7 of 17 5.2 ELEMENT PROPERTIES The following table summarizes the element and material properties assumed in the analysis: Shell Thk [mm] 1 2 3 4 Strand Jack Support Support Can Dia1181mm Exist'g Bottom Flange Plate Additional Top Flange/Stiff Plate Shell Shell Shell Shell PL25 PL32 PL25 PL25 25 32 25 25 Material Yield Strength [Mpa] 248 248 248 248 S/N Description Element Type Shell Grp 5.3 LOAD COMBINATION The following table summarizes all the basic load cases, associated load factors and combined load condition: Basic Load Case Jacket Weight = 73MT* per leg Stand Jack Pull Force = 44MT per leg Load Case STA1 PUL2 Combined Load Condition 1000 1.00 1.00 - Note *Assumed max static vertical load on each leg for design purpose only. Doc. No : UPD-BC-G4-CS-DR-6003 DESIGN OF JACKET STRAND JACK SUPPORT Doc. Class : Discipline : Error! Unknown Revision : D1 Document type: Contractor Job No : 365 System/Subsystem : document property name. Rev. Date : Contract No : 4600006595 Page 8 of 17 5.4 ANALYSIS RESULT The following presents the Finite Element Model Analysis results – Max Von Mises Stresses (Combined Axial, bending, and shear stresses) of the proposed strand jack design: (a) Von Mises Stress – Overall (b) Von Mises Stress – Support Can (32mm thk Pipe Wall) Doc. No : UPD-BC-G4-CS-DR-6003 DESIGN OF JACKET STRAND JACK SUPPORT Doc. Class : Discipline : Error! Unknown Revision : D1 Document type: Contractor Job No : 365 System/Subsystem : document property name. Rev. Date : Contract No : 4600006595 Page 9 of 17 (c) Von Mises Stress – Strand Jack Support Bottom Flange / Skid Frame Top Flange Plate (d) Von Mises Stress – Strand Jack Support Top Flange Plate (with additional flange plate) Doc. No : UPD-BC-G4-CS-DR-6003 DESIGN OF JACKET STRAND JACK SUPPORT Doc. Class : Discipline : Error! Unknown Revision : D1 Document type: Contractor Job No : 365 System/Subsystem : document property name. Rev. Date : Contract No : 4600006595 Page 10 of 17 Findings Generally, the overall stress level (Von Mises Stress) is less than 105MPa. High stress zones (i.e. 186MPa) are limited to areas such as the strand jack bearing surface, mainly attributed to modelling technique using point load at strand jack supporting joint locations. Stress levels on Temporary Support Can are also less than 90MPa (at interface between strand jack support and support can). For detailed FEM Input & Output Files, refer to Appendix – D. Summary Conservatively, max Von Mises Stress is found to be 186.7MPa, which is within the allowable stress (0.80Fy = 0.80 x 248 = 198MPa) as specified in Section 3.0. Therefore, the strand jack design appears to be structurally fit. Doc. No : UPD-BC-G4-CS-DR-6003 DESIGN OF JACKET STRAND JACK SUPPORT Doc. Class : Discipline : Error! Unknown Revision : D1 Document type: Contractor Job No : 365 System/Subsystem : document property name. Rev. Date : Contract No : 4600006595 Page 11 of 17 6.0 MANUAL DESIGN VERIFICATION Doc. No : UPD-BC-G4-CS-DR-6003 DESIGN OF JACKET STRAND JACK SUPPORT Doc. Class : Discipline : Error! Unknown Revision : D1 Document type: Contractor Job No : 365 System/Subsystem : document property name. Rev. Date : Contract No : 4600006595 Page 12 of 17 Doc. No : UPD-BC-G4-CS-DR-6003 DESIGN OF JACKET STRAND JACK SUPPORT Doc. Class : Discipline : Error! Unknown Revision : D1 Document type: Contractor Job No : 365 System/Subsystem : document property name. Rev. Date : Contract No : 4600006595 Page 13 of 17 Doc. No : UPD-BC-G4-CS-DR-6003 DESIGN OF JACKET STRAND JACK SUPPORT Doc. Class : Discipline : Error! Unknown Revision : D1 Document type: Contractor Job No : 365 System/Subsystem : document property name. Rev. Date : Contract No : 4600006595 Page 14 of 17 APPENDIX – A STRAND JACK SPECIFICATION Doc. No : UPD-BC-G4-CS-DR-6003 DESIGN OF JACKET STRAND JACK SUPPORT Doc. Class : Discipline : Error! Unknown Revision : D1 Document type: Contractor Job No : 365 System/Subsystem : document property name. Rev. Date : Contract No : 4600006595 Page 15 of 17 APPENDIX – B WEIGHT CONTROL SUMMARY AND ESTIMATION OF REQUIRED PULL FORCE Doc. No : UPD-BC-G4-CS-DR-6003 DESIGN OF JACKET STRAND JACK SUPPORT Doc. Class : Discipline : Error! Unknown Revision : D1 Document type: Contractor Job No : 365 System/Subsystem : document property name. Rev. Date : Contract No : 4600006595 Page 16 of 17 APPENDIX – C STRAND JACK SUPPORT DRAWINGS Doc. No : UPD-BC-G4-CS-DR-6003 DESIGN OF JACKET STRAND JACK SUPPORT Doc. Class : Discipline : Error! Unknown Revision : D1 Document type: Contractor Job No : 365 System/Subsystem : document property name. Rev. Date : Contract No : 4600006595 Page 17 of 17 APPENDIX – D FEM INPUT & OUTPUT FILE