Ultimate Load Capacity of Group-Pile Supported Jacket Foundations for Offshore Wind Energy Converters

This study was performed to investigate the ultimate horizontal load capacity of an innovative foundation system for large offshore wind energy turbines (i.e. ～5-7 MW) to be constructed in deep waters, ～35-40 m. The ultimate capacity of the standart jacket foundation system with single piles and double-pile supported novel jacket foundation system were estimated using hyperbolic method. Numerical method was used to evaulate the response of the foundations under combined loading in saturated very dense sand. The validation of the developed finite element model for two cases was made using the results of field tests in the literature. The effect of pile length and pile spacing on the ultimate capacity were determined by parametric analysis. The results indicate that the jacket foundation with closely spaced piles provides higher ultimate load capacity and shows a significantly better response than the response of a single-pile configuration with embedded length L, although the total length of the piles is same