I’ve recently discovered the existence of precast foundation for wind turbines. Strangely enough, this solution isn’t having a big success, at least as far as I know.
By the way, there are several clear advantages: first of all, an important time saving.
According to the developer brochure, only 2 days are needed to complete the foundation: the first to install the pieces and the second to connect the tower tensioning the bolts.
Then, as with all serial products, there is the advantage of tighter controls on the quality of the materials and the production
The manufacturer also suggest that the excavation volume is reduced, although I don’t understand why (in the end, it is still a gravity foundation, so the dimensions should be similar).
I also don’t see what happen with the conjunction element (embedded ring or anchor cage in the newer models): I suppose that it will be substituted by bolts enclosed in the precast modules, but I can’t visualize how it will work without the lower flange.
I don’t know how many companies are actives in this business: the picture below are taken from a presentation of Artepref, a Spanish company specialized in precast components.
With reference to the excavation reduction and saving. An in-situ cast base needs working room stable sides to work down at 3m or so depth to complete reinforcement then concrete. ramp access down, etc. with time spent dodging the inclement weather, and achieve a high quality job.
Bring on the precast. over the top of a micro-piled footprint to better root it down. you could always introduce a concrete collar, excavated to form a perimeter beam. before the foundation excavation is started. So then the segments are dropped into place. Like the light house they built way back when. And the method used for caisson shaft sinking.
I would not mind betting the dynamic forces over the foundation can be isolated better in the section design that forms the complete base. easily transported onto site in one day. and built in a day.
Interesting. Not sure that I understood each aspect but am interested in modular foundations ... actually for smaller turbine sizes about 25 meters.