TY - JOUR

T1 - Assessment of Pier Foundations for Onshore Wind Turbines in Non-cohesive Soil

AU - Achmus, Martin

AU - Saathoff, Jann Eike Sören

AU - Terceros Almanza, Mauricio Marcelo

N1 - ACKNOWLEDGMENT This study has been carried out within the ForWind joint research project “Ventus efficiens – Joint research for the efficiency of wind energy converters within the energy supply system,” financially supported by the Ministry for Science and Culture in Lower Saxony, Germany. The authors thank the Ministry for Science and Culture in Lower Saxony for funding and all project partners for constructive cooperation

PY - 2019

Y1 - 2019

N2 - In non-cohesive soil, onshore wind turbines are often found on shallow foundations with a circular or octagonal shape. For the current generation of wind turbines, shallow foundations with very large breadths are required. The foundation support costs thus represent a considerable portion of the total construction costs. Therefore, an economic optimization of the type of foundation is highly desirable. A conceivable alternative foundation type would be a pier foundation, which combines the load transfer over the foundation area at the pier base with the transfer of horizontal loads over the shaft surface of the pier. The present study aims to evaluate the load-bearing behavior of a pier foundation based on comprehensive parametric studies. Thereby, three-dimensional numerical simulations of both pier and shallow foundations are developed. The evaluation of the results focuses on the rotational stiffnesses of the proposed soil-foundation systems. In the design, the initial rotational stiffness is decisive for consideration of natural frequencies, whereas the rotational secant stiffness for a maximum load is decisive for serviceability considerations. A systematic analysis of the results at different load levels shows that the application of the typical pier foundation is presumably limited to relatively small onshore wind turbines.

AB - In non-cohesive soil, onshore wind turbines are often found on shallow foundations with a circular or octagonal shape. For the current generation of wind turbines, shallow foundations with very large breadths are required. The foundation support costs thus represent a considerable portion of the total construction costs. Therefore, an economic optimization of the type of foundation is highly desirable. A conceivable alternative foundation type would be a pier foundation, which combines the load transfer over the foundation area at the pier base with the transfer of horizontal loads over the shaft surface of the pier. The present study aims to evaluate the load-bearing behavior of a pier foundation based on comprehensive parametric studies. Thereby, three-dimensional numerical simulations of both pier and shallow foundations are developed. The evaluation of the results focuses on the rotational stiffnesses of the proposed soil-foundation systems. In the design, the initial rotational stiffness is decisive for consideration of natural frequencies, whereas the rotational secant stiffness for a maximum load is decisive for serviceability considerations. A systematic analysis of the results at different load levels shows that the application of the typical pier foundation is presumably limited to relatively small onshore wind turbines.

U2 - 10.5281/zenodo.3566307

DO - 10.5281/zenodo.3566307

M3 - Artikel

VL - 13

JO - International Journal of Civil and Environmental Engineering

JF - International Journal of Civil and Environmental Engineering

SN - 2010-3883

IS - 10

ER -