Hydrodynamic analysis of multi-body floating piers under wave action

Abstract

Hydrodynamic analysis of a floating multi-body pier interacting with incident waves is carried out and results of wave-induced motions and structural responses are presented. The objective is to develop a procedure, which can be used to analyse the motions of such a floating pier made up of several pontoons that are modelled as a rigid body and connected to each other by flexible and rigid connectors. For a fixed length of floating pier, some alternative arrangements of pontoons with various dimensions are considered and dynamic responses of these alternatives are investigated. Analysis of the multi-body floating structure is carried out in the frequency domain. Three-dimensional diffraction theory is used to predict the dynamic response of modules in irregular waves. Effects of various parameters, such as the beam of pontoon submerged, depth of the pontoon and mooring system on motion, are also studied. To examine the effect of relevant parameters on the pier hydrodynamic responses, motion-amplitude transfer functions (RAO) and connector forces for a wide range of wave frequency and heading angle are computed. The results include prediction of pier motions in any multi-body alternative arrangements and comparison of their hydrodynamics behaviourin different wave frequencies and heading angles. Finally it is shown that the response of the floating pier motions is significantly dependent on pontoon dimension and the characteristics of connector stiffness, the wave conditions and the interactions between the pontoons. Also, operability of a floating pier is investigated by analysing the floating pier due to motion response of a ship due to the neighbouring floating pier under wave condition.