Soil–Structure Interactions for the Stability of Offshore Wind Foundations under Varying Weather Conditions

Fixed-bottom foundations of offshore structures, mainly monopiles, are subject to extreme events and other critical cyclic nature loads. Since wind turbine structures slender, the manufacturers turbines give a range frequencies for safe operation during structure’s life cycle. Highly reliable measurements accurate determination shear moduli damping ratios crucial ensure stability these example, avoid resonance structures. Because foundation–soil properties change over period time due various environmental factors, this should be taken into consideration designs. In current investigation, behaviours dry sand under dynamic loads were explored. Cyclic strain amplitudes 0.05%, 0.1%, 0.25% 0.5% carried out in simple apparatus explore evolution trend stiffness ratio soil. Attempts made simulate varying weather conditions by conducting tests with different representing normal conditions. It was found that soil vary remarkably at first then tend stabilise loading same amplitude. However, amplitude, property variations continue further. From numerical analyses using discrete element method, it is disturbance soil, causing further particle rearrangements compactions, following sudden which leads variations.