PI: Muhannad Suleiman
University: Lehigh University

The goal of this project is to investigate the innovative concept of bio-inspired foundations to improve the response of offshore wind turbines (OWTs). OWTs are commonly supported on dynamically driven monopiles or multiple piles made of steel with a relatively smooth surface. The cost of OWT foundations represent up to 40% of the cost of turbines. Therefore, suction bucket foundations have been recently used to support OWTs due to their cost-effectiveness, easy installation, and reduced environmental impacts. To ensure the stability of OWTs, the design must satisfy strict criteria including those related to stiffness, displacement, and rotation (e.g., rotation serviceability limits of 0.5° at the mudline). However, OWTs are subjected to complex loading conditions, including long-term cyclic vertical and lateral loads, and the reliable operation of these systems depends on understanding the soil-foundation interaction. Long-term cyclic loading may result in excessive displacement due to the degradation of soil-foundation interface resistance.

To improve the foundation performance and soil-foundation interaction, the PI proposes the use of bio-inspired concepts (such as anisotropic friction between snakes and soil, and tree roots) for foundation applications. Although geotechnical engineering national research have recently been focusing on bio-mediated and bio-inspired soil improvement (NSF funding of research center of ~$18.5 million), the use of bio-inspired concept in foundation support to improve the behavior of OWTs has not been investigated.

To validate the proposed concept, this proposal seeks funding to initiate research on sustainable and resilient foundation support for OWTs focusing on evaluating the soil-foundation interface response and small-scale testing of suction buckets. The proposed efforts represent the beginning of a campus-wide initiative within the I-CPIE on bio-inspired mechanical systems and physical infrastructures.

This initiative is envisioned as a multi-disciplinary collaboration between several faculty members from different departments at Lehigh University. The PI currently has two pending research proposals related to offshore foundations, which were submitted to the Bureau of Safety and Environmental Enforcement. Furthermore, the PI is planning to submit proposals to the Deep Foundation Institute (DFI) and the National Science Foundation to further investigate the proposed concept.