We have been designing wind turbine foundations for some time now. I have seen some design of late, say in the last 12 months, where a 4-12 inch layer of Type 3 hardcore has been specified under the base of the wind turbine. This confuses me as I don't want to allow rocking to occur across my foundations. I can only imagine that placing stone with a bearing capacity of 50kN/m² over a ground with bearing capacity >100kN/m² would be foolish. There must be a reason however as I am seeing more and more competitors doing this stone detail. Is it at the behest of the turbine manufacturer so that less stress is developed in the turbine structure and more rocking/flexibility allowed in the foundation??? I would think that in wet conditions, the stone would penetrate the ground and eventually cause rocking and ultimately instability. I don't like it, but I also need to know what I am missing? If something was to fail, I would want the tower to fail, and not my foundations. Can someone explain the logic behind a layer of stone under the foundation for these towers?? I would greatly appreciate this.
Red Flag Submitted
Thank you for helping keep Eng-Tips Forums free from inappropriate posts. The Eng-Tips staff will check this out and take appropriate action.
Reply To This Thread
Posting in the Eng-Tips forums is a member-only feature.