Comparative study of several methods of axial design of piles located in a thick clay deposit: Pierre-de-Saurel wind farm case

ABSTRACT: As part of a wind farm construction project, several methods of piles axial design were used to optimize pile costs. These methods include: Beta method (effective stress analyses) of the Canadian Foundation Engineering Manual, CFEM, 2013; Alpha method (total stress analyses) of the CFEM; a method based on piezocone tip resistances; "U.S. Army Corps of Engineers" method (effective stress analyses); and finally, a method based on the results from the pressuremeters. In order to confirm the results, dynamic loading and pull out tests were carried out on three test piles. The results of this study showed that the Beta method, recommended by the CFEM, is very sensitive to the choice of the piles design parameters. The piezocone-based method gives the closest resistance values to those measured by the dynamic loading test.