3D FE-Informed Laboratory Soil Testing for the Design of Offshore Wind Turbine Monopiles

3D FE-Informed Laboratory Soil Testing for the Design of Offshore Wind Turbine Monopiles

Cheng, Xiaoyang (University of Bristol)
Diambra, Andrea (University of Bristol)
Ibraim, Erdin (University of Bristol)
Liu, H. (Norwegian Geotechnical Institute)
Pisano, F. (TU Delft Geo-engineering)

2021

Based on advanced 3D finite element modelling, this paper analyses the stress paths experienced by soil elements in the vicinity of a monopile foundation for offshore wind turbines subjected to cyclic loading with the aim of informing soil laboratory testing in support of monopile foundation design. It is shown that the soil elements in front of the laterally loaded monopile are subjected to complex stress variations, which gradually evolve towards steady stress cycles as the cyclic lateral pile loading proceeds. The amplitude, direction and average value of such steady stress cycles are dependent on the depth and radial distance from the pile of the soil element, but it also invariably involves the cyclic rotation of principal stress axes. Complementary laboratory testing using the hollow-cylinder torsional apparatus was carried out on granular soil samples imposing cyclic stress paths (with up to about 3 × 104 cycles) which resemble those determined after 3D finite element analysis. The importance of considering the cyclic rotation of principal stress axes when investigating the response of soil elements under stress conditions mimicking those around a monopile foundation subjected to cyclic lateral loading is emphasised.

Finite element analysis
Laboratory testing
Monopile
Offshore
Soil
Wind turbines

http://resolver.tudelft.nl/uuid:63f05356-ac34-442e-a6f1-ee263b639db9

https://doi.org/10.3390/jmse9010101

2077-1312

Journal of Marine Science and Engineering, 9 (1), 1-15

Institutional Repository

journal article

© 2021 Xiaoyang Cheng, Andrea Diambra, Erdin Ibraim, H. Liu, F. Pisano