An experimental investigation on the hydrodynamic performance of floating bridge foundation with taut mooring system

Floating bridges with floating foundations have wide application prospect in deep-water transportation infrastructures. The dynamic properties of floating foundation would deeply affect the structural characteristics of the whole floating bridges. However, limited research works, especially experimental studies, have been conducted to investigate the dynamic behaviors of floating bridge foundations. In this paper, a series of hydrodynamic model tests (including still water tests, regular wave tests, and environmental loading tests) on a floating bridge foundation composed of a floating platform and the mooring system combining tension legs and incline cables, are presented. The test campaign was conducted under the guidance of similarity criteria of Froude and Strouhal numbers, and focused on the structural hydrodynamic responses regarding platform motions and mooring tensions under wave and current loadings. Results show that, the hydrodynamic characteristics of the floating foundation could be quite different in bridge-transversal and -longitudinal directions. The platform dynamic motion is dominated by horizontal displacements, and slight coupling effects between rotational and lateral responses were found. Compared to the wave only conditions, the superposed currents in wave-current combination cases would mitigate the horizontally dynamic responses, and enhance the vertically heave oscillations of the floating foundation. The presented study provides beneficial references for further research on the design and construction of floating bridges in deep-water environment.