Numerical investigation of installation effects on the cyclic behaviour of monopile foundation under horizontal loading

Abstract

This paper presents results of the numerical investigation of cyclic behaviour of monopile foundations for offshore wind power turbine considering effects of the vibratory driven installation process. The dimensions and properties of the soil in the direct vicinity of the pile shaft are based on the experimental investigation. The sophisticated High Cyclic Accumulation model (HCA-model) is used for the simulation of the cyclic lateral loading. This novel approach of refining the numerical soil model for the lateral loading simulation highlights the significance of induced changes in the soil structure due to the installation process. The parameter study shows that a narrow loosening zone directly around the pile shaft increases the lateral deflection of the pile head significantly compared to a homogeneous soil distribution. A wider zone of compacted soil further away from the pile on the other hand only has a negligible influence on the deflection behaviour.