Submarine landslide modelling to evaluate hazard to offshore linear infrastructure

The expansion of offshore renewable energy infrastructure is critical for achieving net-zero carbon targets. However, submarine landslides pose a significant threat to power transmission cables, pipelines, and other linear infrastructure, with high associated economic and operational risks. To address this challenge, we present a novel geotechnical centrifuge model that evaluates the impact of submarine landslides on flexible obstacles. The experimental setup features a tilting mechanism to induce slope failure, simulating landslides in an enhance-gravity scaled environment. The soil material comprises glass beads, and the impacted obstacle is a cylindrical element spanning the centrifuge box transversely. The cylinder, designed to slide laterally upon impact, mimics the flexibility of cables and pipelines lying on the seafloor. An external spring system connected to the cylinder adds resistance, also allowing precise reconstruction of soil-forces and their evolution over time. Both submerged and dry conditions are explored. Preliminary results highlight the influence of obstacle flexibility on force attenuation and displacement patterns. These insights contribute to the understanding of flow-structure interaction in submarine landslides, necessary to update guidelines on impact loads, and providing a foundation for resilient offshore infrastructure design.