Probabilistic Assessment of the Foundation of Offshore Wind Turbines

Offshore wind turbines (OWT) are subjected to loads induced by wind, sea state and operation. During their service life, environmental impacts occur which lead to cyclic loading of the support structure. In this paper the so-called jacket substructure for OWT is investigated. For this kind of substructure, especially the proofs of the ultimate limit state for the axially-loaded foundation piles, are relevant within the structural analysis. Theses structural components are investigated by applying probabilistic methods. The methodical approaches and procedures to determine the load- bearing capacity of the foundation are described. Values of input parameters like wind and sea state are taken into account by their probability distributions. The stochastic pile bearing capacity is derived by applying probabilistic models of the subsoil. The outcomes of the reliability-based analysis are compared with results of the structural analysis as stated in standards.