Effect of the installation process on monopile lateral response

Most offshore wind turbines (OWTs) are supported by large-diameter monopiles, installed impact driving. OWTs dynamically sensitive structures, with a narrow design range for the eigenfrequency. Fatigue and serviceability limit states can be critical in design, so foundation stiffness plays an important role. The pile installation process results changes to soil state, investigated here through large-deformation numerical analyses using coupled Eulerian–Lagrangian approach hypoplastic constitutive relation model sand. state is then mapped small-strain evaluate effect of on lateral response. Complementary physical modelling from monopile load testing centrifuge provide confidence model. Analyses two different sands highlight commonalities differences. Comparison featuring wished-in-place or jacked illustrates characterise allow quantification their effects as driving tends produce stiffer response, expected variations due dimensions sand relative density. Further research will insights into role pore fluid response during investigate vibro-driven piles.