Probabilistic calibration of the p-y method considering model uncertainty for ultimate limit state design of monopiles

Abstract

ABSTRACT The API p-y method is widely used in the design of offshore wind turbines (OWTs) monopiles at present. This study systematically evaluates the model uncertainty of the p-y method for OWT monopiles and proposes a two-stage calibration approach for evaluating the model bias factor. To overcome the difficulty of limited field tests, a high-fidelity base model is employed as a bridge between the field test data to the p-y method. The field test data is used to calibrate the base model and determine the model error of the base model. Synthetic numerical cases are subsequently generated using the base model to evaluate the correction factor of the p-y method. By combining the model error of the base model and the correction factor of the p-y method, the model bias factor of the p-y method can be evaluated. The reliability analysis of the monopile in an offshore wind project in China is taken as an example. The results serve as a valuable tool for correcting the lateral bearing capacity of OWT monopiles based on the specific soil conditions and risk preferences for the offshore wind turbine project.