TY - JOUR

T1 - Bearing behaviour of shallow foundations for wind energy converters on sandy soils under cyclic eccentric loads

AU - Cao, Shuhan

AU - Achmus, Martin

N1 - Funding Information: This study was carried out in the scope of the research project “HyTowering - Optimierung der Bemessung hybrider Türme und Entwicklung eines geeigneten Monitoringkonzepts” funded by Bundesministerium für Wirtschaft und Energie (Germany). Project No. 41V7738. The authors sincerely acknowledge BMWi support.

PY - 2023

Y1 - 2023

N2 - For wind energy converters (WECs), the behaviour under cyclic loading is critical to the operation and lifetime, especially because the cyclic load is associated with eccentricity. In various geotechnical design standards, the eccentricity of shallow foundation for WECs is supposed to be limited. In the German geotechnical design standards, it is specifically required that no gapping shall occur under quasi-static eccentric load. This verification is often decisive in practical design and leads to potential over-dimensioning. The one possible favourable effect of limiting the gapping of WECs on non-cohesive subsoils is to limit the accumulation of permanent rotation under cyclic loads indirectly. In this article, the experimental results of cyclic rotation accumulation of shallow foundation on non-cohesive subsoils from literatures and own medium scale tests are discussed. It is shown that the gapping has no direct influence on the rotation accumulation rate, instead it is the load magnitude relative to the bearing capacity of foundation that is decisive to the cyclic rotation accumulation behaviour. Based on these observations, the verification ‘no gapping under quasi-static eccentric load case’ seems dispensable in the design of WEC shallow foundations on non-cohesive subsoils.

AB - For wind energy converters (WECs), the behaviour under cyclic loading is critical to the operation and lifetime, especially because the cyclic load is associated with eccentricity. In various geotechnical design standards, the eccentricity of shallow foundation for WECs is supposed to be limited. In the German geotechnical design standards, it is specifically required that no gapping shall occur under quasi-static eccentric load. This verification is often decisive in practical design and leads to potential over-dimensioning. The one possible favourable effect of limiting the gapping of WECs on non-cohesive subsoils is to limit the accumulation of permanent rotation under cyclic loads indirectly. In this article, the experimental results of cyclic rotation accumulation of shallow foundation on non-cohesive subsoils from literatures and own medium scale tests are discussed. It is shown that the gapping has no direct influence on the rotation accumulation rate, instead it is the load magnitude relative to the bearing capacity of foundation that is decisive to the cyclic rotation accumulation behaviour. Based on these observations, the verification ‘no gapping under quasi-static eccentric load case’ seems dispensable in the design of WEC shallow foundations on non-cohesive subsoils.

KW - cyclic rotation accumulation

KW - eccentric loading

KW - gapping

KW - geotechnical design verification

KW - medium scale experiment

KW - shallow foundation

KW - Wind energy converter

UR - http://www.scopus.com/inward/record.url?scp=85144009279&partnerID=8YFLogxK

U2 - 10.1080/19386362.2022.2154922

DO - 10.1080/19386362.2022.2154922

M3 - Article

AN - SCOPUS:85144009279

VL - 17

SP - 26

EP - 39

JO - International Journal of Geotechnical Engineering

JF - International Journal of Geotechnical Engineering

SN - 1938-6362

IS - 1

ER -