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Part B - Certificates and approval requirements 
This procedure is essential for all certificates 
• in which soil deformations are contained as a target or influencing parameter 
• in which changes in the soil properties have to be considered 
• in which assumptions are made regarding model parameters due to the lack of determinability 
To the extent that soil deformations are relevant in terms of the design but cannot be predicted with the 
necessary level of accuracy, the resulting problems shall be bypassed using suitable design measures 
if circumstances permit. Otherwise, the observation method is to be used. 
3.2.4.2 Safety certificate concept and process, level of stability against collapse 
Geotechnical certificates of the structural safety of the soil, the foundation elements and their components 
shall be obtained for offshore wind turbines in accordance with the following principles: 
• The mechanisms of the expected interaction between the soil and the structure shall be repre 
sented and considered in the certificates for the foundation elements. 
• In all cases, a certification concept with characteristic soil parameters and partial safety factors on 
the load side and the resistance side (load and resistance factors) shall be used. Deviations are 
permitted in justified cases, in particular if the interaction between the soil and the structure does 
not permit definitive separation between load and resistance or if the resistances are directly or 
indirectly dependent on external effects (e.g. shearing resistances of external loads). In such cases, 
a comparable level of stability against collapse shall be demonstrated. 
• The applicability of the certification process used shall be documented. Violations of the document 
ed application limits shall be evaluated and documented. 
• To the extent that recognised certification processes are unavailable and a separate calculation 
model with calculation processes is designed, the model and the calculation process shall be pre 
sented in a way that permits it to be tested and be comprehensively documented. If the calculation 
results achieved through this method are not without doubt and no major safety reserves in the 
structure are indicated for the problem being dealt with, then the applicability of the model, the 
process itself and its assumptions in the application case shall be verified by a suitable measure 
ment and observation programme on the structure. These measurements and observations form a 
necessary component of the certificate and shall be presented as such together with the certificate; 
this process corresponds to the „observation method“ in accordance with EC7 [20], its elements 
shall be implemented in full (see Appendix 3). 
• Deviations from the level of stability against collapse in accordance with DIN 1054-2005.01 [19] are 
basically permitted for considering the special conditions of the offshore situation, any such devia 
tions shall be indicated and justified. Lower deviations from this level of stability against collapse 
shall require the approval of the BSH, which may engage the services of a suitable assessor for this 
purpose. If different safety concepts and certification processes are used, equivalence of the safety 
statement shall be confirmed by an expert. 
3.2.4.3 Technical codes of practice 
The following technical codes of practice shall be used as the basis, as necessary in the updated version 
at the time when the design basis is defined: 
f11 „Standard for Geotechnical Site and Route Surveys“ 
f201 DIN EN 1997-1:2005-10 
f 191 DIN 1054:2005-01 
Deviations from these codes of practice are permitted in order to consider the special conditions 
of offshore wind turbines. They shall be indicated as such and justified. Final approval of the BSH 
is required for the deviations, and the BSH may engage the services of a suitable assessor for this 
purpose.