Foundations for offshore wind turbines

Abstract

An important engineering challenge of today, and a vital one for the future, is to develop and harvest alternative sources of energy. This is a firm priority in the UK, with the government setting a target of 10% of electricity from renewable sources by 2010. A component central to this commitment will be to harvest electrical power from the vast energy reserves offshore, through wind turbines or current or wave power generators. The most mature of these technologies is that of wind, as much technology transfer can be gained from onshore experience. Onshore wind farms, although supplying 'green energy', tend to provoke some objections on aesthetic grounds. These objections can be countered by locating the turbines offshore, where it will also be possible to install larger capacity turbines, thus maximizing the potential of each wind farm location. This paper explores some civil-engineering problems encountered for offshore wind turbines. A critical component is the connection of the structure to the ground, and in particular how the load applied to the structure is transferred safely to the surrounding soil. We review previous work on the design of offshore foundations, and then present some simple design calculations for sizing foundations and structures appropriate to the wind-turbine problem. We examine the deficiencies in the current design approaches, and the research currently under way to overcome these deficiencies. Designs must be improved so that these alternative energy sources can compete economically with traditional energy suppliers.

Effect of foundation modelling on the fatigue lifetime of a monopile-based offshore wind turbine

“…Piles supporting monopile-based OWTs are subjected to large horizontal loads applied with an arm of about 30-90 m, which results in large bending moments at the foundation. The vertical load is relatively small compared with the horizontal and bending moment loads (Byrne and Houlsby, 2003). Large-diameter piles resist these loads by mobilizing lateral resistance in the soil.…”

Effects of vertical loading on lateral screw pile performance

“…The study focused on dense sand, as Byrne and Houlsby (2003) reviewed many different locations released for the first phase of wind farms (round I) around the UK and it was found that the ground consists mainly of sandy soil.…”

Seismic Response of Bucket Foundations for Offshore Wind Tower

“…Suction caisson, also known as "suction bucket", is a highly competitive alternative for offshore wind foundation due to many advantages compared to the conventional offshore foundations: quick installation, no heavy driving equipment for penetration and no hammering noise (Byrne and Houlsby, 2003;Zhu et al, 2011;Choo et al, 2012;Kwag et al, 2013;Kim et al, 2014a). When the suction caisson foundation is used as a fixed structure installed on the coast, its seismic response should be taken into account as a part of the design procedure.…”

“…Monopiles and gravity base foundation have limitation to be applied in the west coast of Korea due to this soft thick sediment. Various alternative foundations have been investigated for the last decades combining typical foundations with other foundation elements, including multiple composite pile foundations, hybrid foundation and so on (Houlsby and Byrne, 2000;Byrne and Houlsby, 2003;Shin et al, 2014).…”