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Part B - Verifications and approval requirements 
3.3.2.2 Material designations and parameters 
The material parameters used for the subsoil types shall be determined and designated ac 
cording to the relevant DIN standards. Deviating or supplementary processes and designa 
tions shall be indicated as such and comprehensively documented. 
3.3.2.3 Subsoil model and characteristic subsoil parameters 
The current version of the “Standard Ground Investigations - Minimum requirements for geo 
technical surveys and investigations into offshore wind energy structures, offshore stations 
and power cables” shall be applied. 
For each offshore structure site, the set of available survey results shall be used for deriving 
an individual geotechnical subsoil model for the site that shall be used as the basis of the 
verifications. For this purpose (at least) one suitable calculation profile (subsoil profile) shall be 
specified with the required characteristic subsoil parameters of its subsoil layers. If the subsoil 
is non-homogenous, it may be necessary to formulate a more complex subsoil model for each 
offshore structure site with several calculation profiles. 
The characteristic parameters and their probable bandwidths of all subsoil characteristics that 
are relevant for verification shall be defined and specified for the subsoil model. This data shall 
be based on the evaluation of a bandwidth of investigation results and on an expert’s opinion 
based on experience, correlation and/or interpretation of direct and indirect information and 
investigations at the site. 
The values of the applied subsoil parameters shall be derived from the bandwidth of charac 
teristic values with regard to their significance in whichever calculation model is used. Varia 
tions in model calculations shall be provided to an appropriate extent. This shall also apply 
analogously to the parameters in all cyclic and dynamic investigations. 
3.3.2.4 Limit states for verifications 
A differentiation shall be made between the following limit states: 
• Ultimate Limit State - ULS 
• Fatigue Limit State - FLS 
• Serviceability Limit State - SLS 
• Accidental Limit State - ALS, in as far as such conditions exist. 
3.3.2.5 Required verifications 
3.3.2.5.1 Verification of the stability of the seabed 
It shall be demonstrated that the subsoil system on which the verifications for the foundation 
and load calculations for the support structure are based is stable. 
The following items are to be considered in particular: 
• Potential reduction in stability of the seabed due to external influences, such as current and 
wave action, influenced by the substructure, effect of earthquake, offshore operations such 
as pile driving or dredging etc. 
• Potential change in the geometry of the seabed due to influences such as erosion (scouring) 
and suffosion