Optimum geometry of monopiles with respect to the geotechnical design

authored by

Kirill Alexander Schmoor, Martin Achmus

Abstract

In the near future, several offshore wind farms are planned to be erected in the German North Sea. Monopile foundations are often a favorable solution to transfer environmental loads into the subsoil. In most cases, the Serviceability Limit State (SLS) proof is design-driving, i.e., compliance with admissible deflections or rotations of the monopile is key. A crucial point herein is the required limitation of cyclically accumulated irreversible rotations of the pile head due to operational constraints of the wind turbine. Since several design solutions fulfill the technical demands, the most important issue in monopile design is the determination of a suitable monopile geometry, i.e., the diameter D and the embedded length L, which also fulfills economic demands. An optimization analysis was conducted with respect to the geotechnical design requirements and the economic criteria for two optimization targets, namely the minimum pile mass and a combination of the pile mass and the embedded pile length. An optimum slenderness ratio L/D is presented as a function of the required accumulated rotation, system dimensions, and number of cyclic loads. With the presented results, a monopile design can be obtained that fulfills both geotechnical and economic demands.

Organisation(s)

Institute of Geotechnical Engineering

Type

Article

Journal

Journal of Ocean and Wind Energy

Volume

2

Pages

54-60

No. of pages

7

ISSN

2310-3604

Publication date

01.02.2015

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Renewable Energy, Sustainability and the Environment, Water Science and Technology, Energy Engineering and Power Technology, Ocean Engineering

Sustainable Development Goals

SDG 7 - Affordable and Clean Energy

Electronic version(s)

http://legacy.isope.org/publications/jowe/jowe-02-1/jowe-02-1-p054-jcr24-Schmoor.pdf (Access: Open)