Evaluation for p-y Method for Offshore Large Diameter Monopile in Sand

Abstract

Abstract Large monopile is widely used in offshore wind farm due to their relatively simple installation. Monopiles are customarily designed by applying the p-y method. That being said, there is no detailed and uniform interpretation on the reasons for limitations in the current p-y method. An elaborate study is performed to determine the main reasons of such limitations. In this study, a FLAC3D model is presented to evaluate the current p-y method for piles in sand of three different relative densities under a static load, in which the non-linear modulus is taken into account. The results show that the initial stiffness of the p-y method is overestimated and even more magnified in the large depth. The diameter effect should be taken into account under diameters exceeding 3m in loose and medium sand, as well as diameters more than 5m in dense sand.