The design load combination of wind turbine foundation under extreme working conditions is horizontal force Fxy=1673.2kN vertical force Fz=4126.1kN, resultant
4. Partially Prestressed Concrete Foundation Degree of prestressing 0.9 0.9 0.9 1.2 u e P f A ①The pretension of a bolt is defined in accordance with Code for design of steel structures (GB50017) as follows: = nominal lowest ultimate tensile strength; u f = effective diameter of ordinary anchor bolt at threaded section. 0 twk cgk pc ①The criterion that tower and foundation should keep contact under operating load is ensured by: = concrete stress on the windward side under operating load based on SLS; twk pc = concrete compressive stress induced by prestress of bolts; cgk = concrete compressive stress induced by gravity of wind turbine; = percentage of concrete compression force over exterior load. The uncertainties regarding whether ‘Fatigue equivalent load cycle’ can be used for design of reinforced concrete foundation needs to be verified.
The design of most shallow foundations for onshore wind turbines is governed by the gapping control calculation. This verification ensures that soil degradation
The loads for the design are defined with a high degree of accuracy however the resistance of the structure is relatively poorly defined due to a number of factors: • High sensitivity to geotechnical conditions • Bearing pressures • Rotational and lateral stiffness • Settlements • Structural response of reinforced concrete base The foundation design process involves two rela tively independent but related design processes viz. The resulting output from the comparison was as follows: Analysis type Linear elastic Non-linear Saving Approximation Level II Level IV Base diameter 16.2 m 15.5 m Concrete volume 256.6 m3 239.7 m3 7.1% Rebar 23.5 t 17.5 t 34.3% The relatively low level of the saving in concrete is attributed to the fact that for this windfarm site the founding material was extremely good and the base sizing was controlled more by gapping crite ria rather than foundation bearing capacity. Various levels of approximation can be used in the design associated with increasing levels of engineering effort, with Level IV representing a full non-linear model of both the soils comprising the foundation material as well as the concrete struc tural element.
On the tower and pile foundation, strain-gauges are used to measure bending moments in two dimensions at eight vertical stations. Blade loads were measured as
Verification and Inspection.............................................................................................91 APPENDIX A (INFORMATIVE) GLOSSARY.............................................................................94 A.1 GEOTECHNICAL ACTION.........................................................................................................94 A.2 OPERATIONAL LOAD..............................................................................................................94 A.3 CONTRACTING AUTHORITY ....................................................................................................94 A.4 PROJECT MANAGER ...............................................................................................................94 A.5 TECHNICAL SUPERVISOR........................................................................................................94 A.6 GEOTECHNICAL ENGINEER.....................................................................................................94 A.7 OPERATOR.............................................................................................................................95 A.8 GEOTECHNICAL STUDY...........................................................................................................95 A.9 PROJECT MANAGEMENT.........................................................................................................96 A.10 TECHNICAL INSPECTION......................................................................................................96 A.11 MISCELLANEOUS ................................................................................................................96 Final Version 1.1 5/109 July 5, 2011 APPENDIX B: DEVELOPMENT OF THE QREF CALCULATION: DEFINITION OF THE "HALF-MOON" AND SREF ............................................................................................................97 A.12 INFLUENCE OF % FOOTING COMPLETELY COMPRESSED ON MAXIMUM SOIL BEARING PRESSURE 97 A.13 DEFINITION OF THE COMPLETELY COMPRESSED ZONE...........................................................98 A.14 REDUCTION FACTOR IE, OWING TO LOAD ECCENTRICITY IN THE CASE OF A FOUNDATION UNDER ECCENTRIC VERTICAL LOAD .............................................................................................................99 A.15 DEFINITION OF THE COMPRESSED SURFACE AREA SCOMP AND REFERENCE SURFACE AREA SREF 100 APPENDIX C: DEGRADATION CURVES FOR G ACCORDING TO DISTORTION: EXTRACTS FROM THE FRENCH PS92 REGULATIONS GIVING ORDERS OF MAGNITUDE FOR VS..................................................................................................................101 A.16 FOR CLAYEY MATERIAL...................................................................................................101 A.17 FOR GRANULAR MATERIAL...............................................................................................102 APPENDIX D: CALCULATING PLE ACCORDING TO THE IMAGINARY FOOTING METHOD.......................................................................................................................................104 APPENDIX E: TABLE OF FCVD VALUES ..................................................................................105 TO USE THE FOLLOWING TABLE, WE TAKE FCK = FC*.....................................................106 ULS COMPRESSION IN MPA ...................................................................................................107 APPENDIX F: REFERENCES .....................................................................................................108 F.1 GEOTECHNICAL SURVEY..........................................................................................................108 F.2 WIND TURBINES ......................................................................................................................108 F.3 OTHER STANDARD REFERENCES ...............................................................................................108 F.4 PAPERS....................................................................................................................................108 F.5 LEGISLATIVE TEXTS.................................................................................................................108 F.6 TECHNICAL INSPECTION...........................................................................................................108 F.7 EARTHQUAKES ........................................................................................................................108 F.8 MISCELLANEOUS.....................................................................................................................108 F.9 OTHER DOCUMENTS.................................................................................................................108 Final Version 1.1 6/109 July 5, 2011 Notations and Units Latin Notations Notation Description Unit Ap Cross-section of inclusion or column [m²] Asw Surface area of shear force reinforcement [m²] B Foundation
The present research seeks to understand how optimization concepts and Microsoft Excel's optimization capabilities can be used in the design of wind turbine
# Wind Turbine Foundation Design Ch5. ## Uploaded by. The document discusses wind turbine foundation design, including different foundation types, unique aspects of wind turbine foundation design, and driving forces. It also outlines the design process, from obtaining load and site data, preliminary design, required checks, and quality control. ## Share this document. ## Footer menu. ## Support. ## Legal. ## Social. ## Get our free apps. Scribd - Download on the App Store. Scribd - Get it on Google Play.