Analysis and Design of Tower Support Structures and Foundationfor Onshore Wind Turbines

Wind turbines (WTs) shall be certified based on acomprehensive evaluation of the structural integrity ofthe tower and foundation system according to applicableCertification Agency Guidelines (CAG). Unlikeconventional structures, the local building code's lack ofspecific provisions for WTs support structures designmay make it insufficient to serve alone as a reasonabledesign basis. A critical point that should be considered isthat any less stringent standard or provision from CAGshould not be used to undercut or violate the localbuilding code requirements and vice versa. Thisconsideration needs a thorough knowledge of localbuilding codes and CAG requirements. Since thecommercial wind turbine industry evolved in Europe andbecause wind turbine manufacturers are part of a globalmarket, a mix of international, European, and localstandards in project construction documents is almostunavoidable. Since there may be more than one standardagainst which a WT is evaluated, this article attempts toclarify the overlaps or fill the gaps between alternatestandards and local practice. For this purpose and toprevent the designer from inconsistent structural design,some of the most widely used codes and guidelines havebeen evaluated and compared with local practices andstandards of Iran.