TY - JOUR
T1 - Geotechnical aspects of offshore wind turbine dynamics from 3D non-linear soil-structure simulations
AU - Kementzetzidis, Evangelos
AU - Corciulo, Simone
AU - Versteijlen, Willem G.
AU - Pisanò, Federico
N1 - Accepted Author Manuscript
PY - 2019
Y1 - 2019
N2 - The development of the offshore wind industry is motivating substantial research efforts worldwide, where offshore wind turbines (OWTs) of increasing size are being installed in deeper water depths. Foundation design is a major factor affecting the structural performance of OWTs, with most installations founded to date on large-diameter monopiles. This work promotes advanced 3D finite element (FE) modelling for the dynamic analysis of OWT-monopile-soil systems. A detailed FE model of a state-of-the-art 8 MW OWT is analysed by accounting for dynamic soil-monopile interaction in presence of pore pressure effects. For this purpose, the critical-state, bounding surface SANISAND model is adopted to reproduce the hydro-mechanical cyclic response of the sand deposit. The response to realistic environmental loading histories (10 min duration) are simulated, then followed by numerical rotor-stop tests for global damping estimation. While linking to existing literature, all FE results are critically inspected to gain insight relevant to geotechnical design. The modelling tools adopted (i) support the robustness of 'soft-stiff’ foundation design with respect to natural frequency shifts, even during severe storm events; (ii) provide values of foundation damping in line with field measurements; (iii) suggest that pore pressure effects might more likely affect soil-monopile interaction under weak-to-moderate environmental loading.
AB - The development of the offshore wind industry is motivating substantial research efforts worldwide, where offshore wind turbines (OWTs) of increasing size are being installed in deeper water depths. Foundation design is a major factor affecting the structural performance of OWTs, with most installations founded to date on large-diameter monopiles. This work promotes advanced 3D finite element (FE) modelling for the dynamic analysis of OWT-monopile-soil systems. A detailed FE model of a state-of-the-art 8 MW OWT is analysed by accounting for dynamic soil-monopile interaction in presence of pore pressure effects. For this purpose, the critical-state, bounding surface SANISAND model is adopted to reproduce the hydro-mechanical cyclic response of the sand deposit. The response to realistic environmental loading histories (10 min duration) are simulated, then followed by numerical rotor-stop tests for global damping estimation. While linking to existing literature, all FE results are critically inspected to gain insight relevant to geotechnical design. The modelling tools adopted (i) support the robustness of 'soft-stiff’ foundation design with respect to natural frequency shifts, even during severe storm events; (ii) provide values of foundation damping in line with field measurements; (iii) suggest that pore pressure effects might more likely affect soil-monopile interaction under weak-to-moderate environmental loading.
KW - Cyclic loading
KW - Damping
KW - Hydro-mechanical coupling
KW - Monopile
KW - Natural frequency
KW - Offshore wind turbine
KW - Sand plasticity
UR - http://www.scopus.com/inward/record.url?scp=85061565565&partnerID=8YFLogxK
U2 - 10.1016/j.soildyn.2019.01.037
DO - 10.1016/j.soildyn.2019.01.037
M3 - Article
AN - SCOPUS:85061565565
SN - 0267-7261
VL - 120
SP - 181
EP - 199
JO - Soil Dynamics and Earthquake Engineering
JF - Soil Dynamics and Earthquake Engineering
ER -