USE OF THE PILED RAFT FOR THE OPTIMIZATION OF WIND TURBINE FOUNDATION
Piled raft; Wind Turbine; Finite Element Method; Optimization; Numerical analysis.
In this work, a study is made on the use of the piled raft as the foundation of an wind turbine located in the city of Macau, in the northeast of Brazil, using the Finite Element Method. The original design of the tower foundation did not consider the raft-soil contact in the system's performance. Thus, this article aims to evaluate the behavior of the foundation admitting the raft-soil contact, that is, considering that the foundation is a piled raft. Analyzes were carried out reducing the number of piles and varying their position in the foundation, in order to assess the system's behavior and find the optimal foundation proposal, that is, with the lowest number of piles and meeting the safety criteria. From the analyzes, with the Plaxis 3D Foundation® software, it was observed that in the piled raft with 24 piles (PR24A), the raft presented a good performance, mobilizing 66% of the vertical load applied to the foundation. In the analyzes with variations in the number of piles, it was possible to perceive that the safety factor to the vertical load assumes high values, even in the raft without piles. Regarding translational stiffness, it was observed that even the isolated raft met the minimum value required by the tower manufacturer. Finally, it was concluded that the limiting factor for the optimization of the foundation was related to differential settlements (evaluated in terms of angular distortion and rotational stiffness) and the optimized foundation was a piled raft with 6 piles.