The crossing of deep fjords that are several kilometers wide calls for significant extensions of present bridge technology. Floating suspension bridges, which represents a combination of offshore ocean engineering and bridge engineering, are one of the proposed solutions.
 

The infrastructure has to resist extreme environmental loads, and floating suspension bridges represent new challenges when it comes to prediction of the dynamic behavior. Engineers need to model both hydrodynamic and aerodynamic loads, leading to a complex interaction between the moorings, floating towers, and the bridge deck. NTNU has developed a model framework for fluid-structure interaction where hydroelastic, aeroelastic, and non-linear structural behaviour are considered.

Furthermore, uncertainty analysis is used to quantify the importance of the basic variables in order to identify further research priorities. There is a special focus on the stability of the structure in strong winds, prediction of the extreme values of the dynamic responses, and simplified methods that may be useful in the initial design phase.

Numerical model in Abaqus CAE of a floating suspension bridge (leftmost picture) and panel model of TLP in hydrodynamic software (rightmost picture). Model and illustration by NTNU/Sondre Halden, Shun Wei Gong and Yuwang Xu.