Static and Cyclic Response of Novel Gravity Base Foundations for Offshore and Onshore Wind Turbines

The increasing need for renewable energy has resulted in the swift proliferation of wind power, both onshore and offshore. In order for the adequate development of off shore wind industry, it is necessary to resolve some uncertainties with regards to foundation employed for these structures. With wind turbines becoming larger and more powerful, the need for strong, stable, and efficient foundation systems is more critical than ever. Till recently monopoles are widely used in case of offshore wind structures across the world but due to surge in capacity of offshore wind production across the world, there needs an efficient and alternate foundation systems. The alternative foundations such as gravity based foundations (GBF) basically resists large compressive loads apart from cyclic loads subjected due to wind and wave actions. These foundations are placed at shallow depth having sound bearing stratum and having larger width of foundations. The present study focuses on the static compressive performance of newly designed, prefabricated GBF models with and without fins or ribs to enhance the load bearing capacity. An attempt is also made to vary the rib shape, number, and thickness, to enhance load bearing capacity and efficient material distribution. A series of laboratory tests were performed on model gravity based foundations embedded in dry sand. The findings indicate that the inclusion of ribs with enhanced thickness markedly enhances the ultimate bearing capacity and stiffness of GBFs. Additionally, the study further investigates the influence of rib thickness on settlement control and elastic rebound under cyclic loading. Key parameters such as coefficient of elastic uniform compression (Cu) and modulus of elasticity were evaluated to understand the soil structure interaction more effectively. The experimental findings support the use of ribbed GBFs in both onshore and offshore wind farms, offering a practical solution for foundation-related challenges. This research bridges the gap between theoretical concepts and practical applications, contributing valuable insights toward the future development of cost-effective and high performing wind turbine foundation systems.