Cyclic overlay model of p-y curves for laterally loaded monopiles in cohesionless soil

verfasst von

Junnan Song, Martin Achmus

Abstract

The bearing behaviour of large-diameter monopile foundations for offshore wind turbines under lateral cyclic loads in cohesionless soil is an issue of ongoing research. In practice, mostly the p-y approach is applied in the design of monopiles. Recently, modifications of the original p-y approach for monotonic loading stated in the API regulations have been proposed to account for the special bearing behaviour of large-diameter piles with small length-To-diameter ratios. However, cyclic loading for horizontally loaded piles predominates the serviceability of the offshore wind converters, and the actual number of load cycles cannot be considered by the cyclic p-y approach of the API regulations. This research therefore focuses on the effects of cyclic loading on the p-y curves along the pile shaft and aims to develop a cyclic overlay model to determine the cyclic p-y curves valid for a lateral load with a given number of load cycles. A stiffness degradation method (SDM) is applied in a three-dimensional finite element model to determine the effect of the cyclic loading by degrading the secant soil stiffness according to the magnitude of cyclic loading and number of load cycles based on the results of cyclic triaxial tests. Thereby, the numerical simulation results are used to develop a cyclic overlay model, i.e. an analytical approach to adapt the monotonic (or static) p-y curve to the number of load cycles. The new model is applied to a reference system and compared to the API approach for cyclic loads.

Organisationseinheit(en)

Institut für Geotechnik

Typ

Artikel

Journal

Wind Energy Science

Band

8

Seiten

327-339

Anzahl der Seiten

13

ISSN

2366-7443

Publikationsdatum

08.03.2023

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Erneuerbare Energien, Nachhaltigkeit und Umwelt, Energieanlagenbau und Kraftwerkstechnik

Ziele für nachhaltige Entwicklung

SDG 7 – Erschwingliche und saubere Energie

Elektronische Version(en)

https://doi.org/10.5194/wes-8-327-2023 (Zugang: Offen)