Large Deformation Finite Element Analysis For Bearing Capacity Of Suction Caisson In Marine Clay

Floating offshore wind turbines structures are heavily dependable on a reliableanchoring system to guarantee safety during offshore foundation operations.Suction caissons are suitable for particularly precise installation,re-use,and deliver large bearing capacity.Suction caissons have often been used on a variety of offshore structures and at present they are considered as a foundation for floating wind turbines.However,no systematic study on floating wind turbines was done for the northern region of South China Sea.The current research is performed on the large deformations for bearing capacity of suction caisson in marine clay of northern part of South China Sea to bridge this gap.In this work,a two-dimensional axisymmetric finite element model(FEM)is established to study the behaviour of suction caisson foundations relative to the marine soft clay under undrained conditions against the pull-out loading by using commercial software ABAQUS/EXPLICIT.The Arbitrary Lagrangian-Eulerian(ALE)technique is adopted to simulate the large deformation of soil caused by pull out of anchors.The studied parameter includes,loading point,soil cohesion,geometry and initial stress state(K_o).The friction contact interface and contact surfaces are the considered parameters for soil-caisson interaction.The variations in friction angle of soil along the Soil-Caisson surface are measured and have rising effect on the pull-out capacity.The pull-out force with displacement curve is obtained by the finite element model.It is found that the pull-out capacity of suction caisson finite element model shows the increasing trend with an increase in friction angle(?)of soil.Through the finite element study and the improved Abaqus/Explicit analysis,it is found that the suction caisson applied in marine clay;can accurately predict the bearing capacity of suction caisson during the pullout process.This can increase the design effectiveness and diminish the cost.These outcomes provide the numerical basis for the design to use the suction caisson foundation in the South Ocean of China,which will be beneficial for ocean engineering of resource exploration.Though,the enhanced numerical analysis in this study still has certain restrictions.Conclusively,the measured parameters are helpful for the effective and reliable geometry design of offshore wind turbines.