Hydrodynamical Aspects of Pontoon Optimization for a Side-Anchored Floating Bridge

Abstract

Long floating bridges supported by pontoons with span-widths between 100 m and 200 m are discrete hydro-elastic structures with many critical eigenmodes. The response of the bridge girder is dominated by vertical eigenmodes and coupled horizontal modes (lateral) and rotational modes (about the longitudinal axis of the bridge girder). This paper explores the design principles used to reduce the response with regards to these eigenmodes. It is shown for a floating bridge with 200 m span-width that by inserting a bottom flange the vertical eigenmodes can be lifted out of wind-driven wave regime. It is also shown that selecting a pontoon length that leads to cancelation of horizontal excitation forces is beneficial, and that the geometrical shaping of the pontoon can be efficient to decrease the bridge response.

Special Issue Honoring Professor Torgeir Moan

“…Iijima et al [3] studied the uncertainty of wave-induced vibrations of large container ships due to ship operation an important aspect that is related to the hydro-elastic response of those structures. Fredriksen et al [4] dealt with hydrodynamic aspects related with a floating bridge, a type of structure that has been attracting much interest in Norway in the last few years. Two papers dealt with collision problems, one a ship collision with a floating bridge [5] and the other about the collisions of a moored structure with moving broken ice driven by current and wave [6].…”

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

“…In the past few years, researchers have conducted preliminary numerical analyses regarding to the floating bridge foundations. Fredriksen et al (2016Fredriksen et al ( , 2019 carried out a hydrodynamic analysis for evaluating the performance of floating foundations with the platforms in different geometric shapes, and the results shown that the elliptic cylindrical platform has the prior performance compared to the other considered geometries. Based on finite element simulation, Xiang et al (2017) investigated the effect of the platform heave plate on the bridge responses, concluding that a properly designed heave plates on the floating platform can lead to a reduction of the maximum bending moment in bride girder.…”

Homogeneous Wave Load Effects on the Connections of Main Parts of Side-Anchored Straight Floating Bridge

“…Fredriksen et al [5] performed a hydrodynamic model of SASB to analyze the global bridge response. ey tried to reduce the wave forces on the floating bridge girder by changing the pontoon geometry and adding a bottom flange.…”