Analysis Of Hydrodynamic Force And Motion Response Of Floating Pier Under Wave Loading

21st century is known as ocean century, using floating structures to develop marineresources and space has attracted the attention of many ocean engineering scholars. Owingto the poor conditions of place and foundation in coastal and offshore engineering, whichbrings difficulty to transportation and materials handling in early construction, researchersconsider using floating pier to solve the problems. Floating pier is fixed up mainly innearshore waters, which is applied to walking, offloading and delivering supplies to coast.In this paper, based on three dimensional potential flow theories AQWA software wasused for hydrodynamic and motion response analysis of single pontoon and floating pier.Hydrodynamic force of single pontoon under amplitude wave was analyzed in thepaper. The change rules of added mass, radiation damping, first-order wave force andsecond-order steady drift force in different depths and incident angles were obtained. Basedon hydrodynamic results, the mooring system of single pontoon in shallow water wasdesigned. RAO under different incident angles and different wave periods of regular wavewas analyzed, and incident angles were among90°~180°, wave periods were among2.5s~7.5s. The results indicated that the single pontoon should be arranged in the directionof incident wave to ensure smaller heaving value. In addition, to ensure smaller yawingangle, the pontoon should be avioded120°incident angle with wave.Hydrodynamic parameters and motion response characters of light-load floating pierwere calculated and compared. In the highest sea state of operating status, in five waveperiods among4.0s~8.0s,180°incident angle, the maximum relative surge and heave valuewas got. When wavelength was roughly equal to once pontoon length, the relative surgevalue was small. Moreover, when wavelength was1.5times pontoon length, the relativesurge value was large. In addition, in wave period of6.0s, surge center of pontoons inlight-load floating pier and single pontoon was compared. In the highest sea state of livingstate, the anchor safety factors of mooring system could meet the engineering requirements.When wave period was certain and wave height was0.5m,1.0m,1.5m,2.0m, the maximumsurge and heave relative value was compared, in addition, time-domain curves of spacebetween pontoons and change rule was got.The connecting device of heavy-load floating pier was designed, and hydrodynamicforce was analysied for50-meter platform, meanwhile, mooring system was designed in the paper. And on this basis, the coupled motion response of heavy-load floating pier andmooring system in different wave heights and periods was calculated, and wave periodswere among7.0s~9.0s, wave geights were among1.0m~2.5m. The corner of adjacentfloating body was analyzed. It showed that the angle between50-meter platform and heavypontoon changed the least as the wave period was8.0s, while was the biggest at9.0s. Whenwave height was1.0m and1.5m, the minimum angle appeared at wave period of8.0s. Andthat appeared at7.5s with the wave height of2.0m and2.5m.This paper built up calculation model of offshore floating pier and analysis was given,the results could provide refrence for the design of floating pier.