Hagemann, AnneAnneHagemannGrabe, JürgenJürgenGrabe2024-12-052024-12-052024-06Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE 8: v008t10a005 (2024)978-0-7918-8786-8https://hdl.handle.net/11420/52291The current design practice for offshore monopiles applies widely accepted simplifications of complex irregular loading scenarios. Highly cyclic loads from varying directions offshore are simplified by means of classification methods. This procedure involves reordering individual cycles in irregular loading scenarios by frequency, mean load, and amplitude. This approach is based on the assumption that the resulting accumulated deformation in the soil is independent of the ordering of the cycle packages, i.e. the validity of Miner’s rule. Different contributions in literature investigate the validity of Miner’s rule by evaluating the effect of the ordering of cycle packages on the resulting damage in the soil, i.e. the accumulated volumetric strain. This paper addresses the question of the validity of Miner’s rule from a different perspective. It investigates the load-displacement behaviour of sand in direct simple shear tests due to dynamic load scenarios. Hence, the load sequences during testing vary while the energy spectrum being employed to generate the irregular load signals remains constant. This method enables capturing natural conditions offshore during testing and allows for comparing individual loading scenarios as the wave spectrum in the frequency domain defines the distribution of wave amplitudes. The test program is carried out on medium dense fine silica sand. The test results are evaluated regarding the accumulated volumetric strain and relate to previous studies on the validity of Miner’s rule in sand.enfatigue | irregular cyclic soil behaviour | offshore | wave loadingTechnology::600: TechnologyConference Paper10.1115/OMAE2024-124051Conference Paper