With the growing know-how and experience about wood as a construction material, its remarkable environmental properties, ease of installation and high strength-to-density ratio make it an appealing choice for designers. However, the low density of wood presents challenges for slender timber bridges, which can experience high accelerations under dynamic loads. Resonance becomes a significant concern when the natural frequencies of the bridge are low, approaching walking frequencies of pedestrians – around 2 Hz vertically and 1 Hz horizontally.This master thesis investigates the dynamic properties of Haradal Bridge, an 87 m long cable-stayed timber bridge. The bridge consists of six deck frame sections, attached to each other by slotted-in steel plate connections. Each section features two primary beams, connected with crossbeams and steel rods arranged in a cross-bracing (X-shape). Due to the stiffness reduction caused by these connections, their influence on the bridge’s dynamic behavior was studied through finite element modeling. Dynamic measurements were conducted on one deck frame section in laboratory conditions and the study explored whether the results from one section could be extrapolated to full bridge.To accurately match the natural frequencies and corresponding mode shapes, several calibrations were implemented to the 1 deck frame section model. The density and stiffness properties of GL28c timber material were increased beyond the standard values provided in EN 14080. Additionally, the steel bracing rods modeled with an elasticity modulus of 210 GPa, which yielded more accurate results. While a good match was achieved for the fundamental modes, these modifications still remain as uncertainties that should be treated with caution.For the full bridge model, the use of springs between the deck frame sections, as well as between the primary beams and crossbeams, led to a reduction in natural frequencies. Spring stiffness values were calculated using the Kser method from EN 1995-1-1, and a sensitivity analysis was performed by varying these values. Across all models, lateral vibration modes were the most affected by the introduction of springs, experiencing approximately 25% lower frequencies, while vertical modes remained mostly unaffected.