<![CDATA[Submerged Floating Tunnel (SFT) is one of the alternative infrastructures for crossing transportation routes over deep and wide waters, but it still requires further studies on the dynamic responses caused by wave forces. Wave forces can induce vibrations and structural deformations, which, if not carefully accounted for, may lead to resonance phenomena. Despite various numerical and analytical models developed in previous studies, experimental validation under controlled wave excitation remains scarce, particularly regarding the influence of mooring configuration and structural mass. Moreover, limited studies have examined how these parameters affect the stiffness-damping balance, which is critical to avoiding dynamic amplification. This research addresses this gap by providing a combined experimental and analytical investigation on the coupled effects of mooring angle and tube mass. This research aims to evaluate the dynamic response of a Tension Leg-type SFT segment model subjected to wave disturbances. The SFT segment model, made of a 3-inch (76 mm) diameter tube with a length of 700 mm, is installed at a depth of 1/6 z below the water surface. The parameters tested include the effect of the cable anchor slope angle (variations: 15°, 30°, and 45°) and the effect of tube mass (variations: 0.5 kg, 0.75 kg, and 1 kg). The displacement response of the specimens is identified from video recordings using video tracking software. This research was conducted using the damped forced vibration theory approach, exploring the relationship among the three main elements of structural dynamics: mass (?), damping (?), and stiffness (?). The damping factor was determined experimentally using the logarithmic decrement method, while the equivalent horizontal stiffness was calculated based on the mooring configuration, taking into account the inclination angle, initial tension, and mechanical properties of the mooring cable. The experimental results show that increasing the inclination angle of the mooring cable leads to smaller structural displacements. Additionally, a greater tube mass results in larger displacements. The experimental data exhibit good agreement with the theoretical model of a single degree of freedom damped forced vibration, with deviations below 10%. Therefore, this study recommends using the largest feasible mooring angle and the smallest practical tube mass for optimal SFT design—within the constraints of real-world applications. This research provides a significant contribution to the understanding of the interrelationship among the fundamental elements of dynamic response and supports the development of continuous models of SFT through advanced numerical approaches, such as the Direct Integration – Mode Superposition Method (DI-MSM).]]>
