Annex 4 
47 
Numerical models for geotechnical certificates 
Preparing certificates of stability against collapse using numerical methods in geotechnology is not the 
recognised state of the art in Germany. Building blocks for standardised procedures have been worked 
out in the form of recommendations by working group AK 1.6, Numerical Systems in Geotechnology of 
the Deutsche Gesellschaft für Geotechnik (DGGT). 
Numerical models using the FE method make it possible to use continuum mechanical calculation mo 
dels on complex structures even when taking account of the ground, although with major simplifications; 
they do not necessarily produce more accurate calculation results. 
Special ground properties, interactive processes and complex procedures can be studied in principle 
and qualitatively using numerical models, however quantitative studies cannot necessarily be repro 
duced or represented reliably. System changes due to cyclical processes cannot be represented with 
sufficient reliability as a rule. 
Plausibility checks represent a significant element in assessing numerical calculation results, e. g. by 
comparing them with areas of experience. Where adequate experience with foundations for comparable 
offshore wind farms is not available, particular value shall be placed on formulating simple analytical 
models and on making a critical and cautious evaluation of the results when designing of the foundation 
elements and assessing their interaction with the support structure.