Physical modelling of monopiles in sand: a generalized scaling law and long-term cyclic response
Physical modelling of monopiles in sand: a generalized scaling law and long-term cyclic response
In this Bright Spark Lecture paper, the author presents two contributions to physical modelling of offshore wind monopiles in sand. First, a generalized scaling law is developed for laterally loaded monopiles in drained sand. The framework links each monopile to an equivalent rigid-pile twin rotating about a centre located approximately 0.75L below the seabed, with dimensionless quantities accounting for pile diameter, embedded length, loading eccentricity, stress level and finite section stiffness. Validation against MIDAS centrifuge tests and literature datasets shows that the framework can unify responses across different geometries, g-levels and testing conditions. Second, a unique MIDAS centrifuge dataset on long-term cyclic loading of monopiles in drained dense sand is interpreted. The dataset includes 2 monotonic and 21 cyclic tests, covering cyclic load amplitude, cyclic load ratio, loading sequence and monotonic preloading. The results show rapid early rotation accumulation followed by stabilization, non-monotonic effects of cyclic load ratio, measurable loading-sequence dependency and relatively stable loading-unloading stiffness. Comparisons with 1g-based empirical models highlight the importance of stress-correct physical modelling for cyclic monopile design.
Huan Wang
11th International Conference on Physical Modelling in Geotechnics (ICPMG2026)
Keynote Papers
https://doi.org/10.53243/ICPMG2026-465