This thesis presents a dynamic finite element investigation of an innovative hybrid foundation for onshore wind turbines, integrating granular anchor piles (GAPs) with conventional concrete piles and an anchor-cage connection. A K₀ geostatic initialization establishes in-situ stress and porepressure conditions, after which the foundation system is introduced and subjected to three loading scenarios in PLAXIS 3D: extreme static loads, pseudostatic seismic loading, and two-way cyclic wind loading. Soil material’s behavior is described by the Mohr-Coulomb constitutive model, linear-elastic behavior for concrete and steel, with node-to-node anchors inside the GAPs.Under extreme static condition, the maximum vertical settlement of -20.8 mm remains well within the 50 mm serviceability limit, and differential settlement produces a total moderate tilt of 8 mm, demonstrating adequate stiffness and load distribution. Pseudostatic analysis (applying a 0.3 g horizontal inertia force) yields total displacements up to 212 mm, a 53 % increase over static, indicating that further reinforcement or layout adjustments would be required. Under 10 cycles of harmonic wind-induced loading, the foundation exhibits an initial compactiondominated settlement followed by stable sinusoidal oscillations with amplitudes on the order of 10⁻⁵ m, confirming strong fatigue resilience under operational wind reversals.Concrete piles carry most bending moments (up to 5.9 MN·m) and axial forces (from -973 kN to +122 kN), with peak stresses concentrated in the upper third of piles aligned with the moment couple. GAPs mobilize primarily axial resistance, reaching full plastic yielding under extreme loads. The bending moments are 60-70% smaller than in concrete piles, similarly the axial forces are 50-60 times smaller than in the concrete piles. Gapping criteria analyses based on DNV/Risøhandbooks reveal effective contact ratios dropping below 50 % when overturning moments exceed ~57 800 kN·m, with corresponding contact pressures rising by over 100 % relative to zeroeccentricity, highlighting the existence of local gapping and the risk of different failure modes under large eccentric loads.In summary, the hybrid GAP–concrete foundation system meets static serviceability and demonstrates robust cyclic behavior under wind loads but requires design refinement for seismic and high-eccentricity scenarios. These findings inform Vattenfall’s next R&D phase and offer a pathway to more sustainable, low carbon foundation solutions for future wind turbine deployments.