Wind Turbine Foundations

[ItsOnlyMud]

Does anyone have any experience of designing wind turbine foundations, especially the dynamic loads. Looking at both spread and piled FNDs. ANy advice greatly appreciated.

 

[iandig]

Not design but investigation. Expensive and detailed! I will look through the contacts who we have done this for and see if I can track down siome useful contacts for you. The last organisation were German, so amy take a few days.

 

[PSlem]

Amy B. Cerato, Ph.D., University of Oklahoma, presented Designing Small Wind Tower Guyed Cable
Foundations Using Helical Anchors Subject
to Dynamic Loads at the DFI seminar in CA. She has done considerable research on it.

 

[STVU]

I did one design about 80% of the way. It depends on the loadings, are we talking about 2MW or 800KW turbine? Then you looks at your soils profile. For smaller turbine foundations, and with dense or hard soils, shallow foundation is feasible economically. With the larger turbine foundations, only deep foundation is recommended-moments are in excess of 40,000 ft kips.

Foundation Analysis & Design, Bowles, 1988 edition has Rocking stifness & other dynamic properties. Check, however, with the turbine manufacturer on the allowable range.

In the end, you will need to have the structural designer help with modelling, determining loads per pile, uplift resistance, connection design etc.

 

[BigH]

For a case history - Design and Construction of Nysted Offshore Wind Farm, Denmark - see Deep Foundation Institute's Magazine "Deep Foundations", Winter 2008 issue, pages 47 to 50.

 

[ItsOnlyMud]

We are talking 3 to 5MW turbines, 1,500 tonnes, moments up to 60,000kNm. The turbine manufacturer will construct 20m diamater mass concrete bases and appears to be looking at spread FNDs. Personally, I would pile the bugger to bedrock!

Any ideas on estimating settlements under dynamic loads from dynamic stiffness moduli Gd and Ed?