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Part B - Verifications and approval requirements 
Verifications in the Fatigue Limit State (FLS): 
• During the verification control process, the special issues related to offshore structure fa 
tigue shall be accordingly taken account of alongside the provisions contained in the res 
pective rules of technology introduced by the construction authorities during the fatigue 
verification process. Suitable measures with respect to special boundary conditions such 
as implementation in seawater in the North or Baltic seas (please compare this with the cor 
rosion regulations for offshore areas), free corrosion areas, or aspects connected with incre 
ased load change figures (please compare this with the DIBt guideline for wind turbines), 
shall be included in the draft. 
• For amendments with respect to verifications in the fatigue limit state, please refer to Ap 
pendix 4 (for offshore wind turbines) and Appendix 5 (for offshore stations). 
Verifications in the Serviceability Limit State - SLS: 
• Limitation of deformation, possibly also accelerations, 
• Limitation of concrete compressive stresses, concrete, resp. prestressed steel stresses and 
decompression and 
• Limitation of concrete crack widths. 
Verifications of durability: 
• Verification of the corrosion protection concept: 
- Cathodic corrosion protection with sacrificial anodes in combination with coatings or by 
impressed-current systems and 
- Coatings 
- Allowance for rust in areas on which high demands are placed. 
Verifications in the Accidental Limit State - ALS: 
• In as far as such conditions exist. 
Evaluation of hull-retaining properties of the support structure: 
• Appropriate verification detailing the potential damage to a ship’s hull on collision between 
an unmanoeuvrable ship and the support structure of an offshore wind turbine 
Special points to be considered in connection with the verification of steel structures: 
• The stability verification for circular cylindrical shells may be obtained by proceeding in ac 
cordance with the DIBt guideline “Wind turbines - Actions on and verification of stability 
against collapse for tower and foundation” (October 2012). 
• Verification of the fatigue limit state for driven piles (also for monopiles) shall take account 
of the proportion of damage resulting from the actual pile-driving process. 
• When designing the shear keys in a grouted joint connection, in particular, one should not 
ignore the possible overlap of bending moments with vertical force. Both the choice of ma 
terials and the verification of the design calculations are subject to an individual Technical 
Approval from the respective approval authority. 
• Static verification of grouted joint connections may be obtained in accordance with the re 
commendations of GL or DNV using the finite element method and, if necessary, confirmed 
by laboratory tests conducted by an accredited test institute.