Large Deformation Numerical Study On The Pullout Capacity Of The OMNI-Max Anchor In Sand

As the latest development and benchmark of gravity installed anchors,the OMNI-Max anchor is widely studied and applied due to its excellent working performance and strong adaptability.Most of the researches on the pullout capacity property of the OMNI-Max anchor are carried out in clay,but the research in sand is a blank.However,sand is also the main form of seabed soil and widely distributed.Gaining full understanding of the pullout capacity property of the OMNI-Max anchor in sand is not only beneficial to study the working performance of the OMNI-Max anchor,but also to study its comprehensive kinematic behaviors in the seabed,which is of great significance to the engineering application and safety control of mooring system.In this study,the large deformation finite element analysis method combined with coupled Eulerian-Lagrangian technique is adopted,and bounding-surface plasticity model is taken as the constitutive model to capture the characteristic of sand.The effects of the anchor embedment depth,the soil relative density,the anchor orientation,the loading angle and the bearing area on the pullout capacity property of the OMNI-Max anchor in sand are investigated.By designing and analyzing the cases of different influential factors,the law of influential factors is acquired.With the increase of embedment depth,the end bearing capacity factor shows a decreasing trend,and the decreasing range continues to slow down;With the increase of relative density,the end bearing capacity factor increases,and the smaller the embedment depth is,the faster the value increases;For anchors with different orientation,the value of the end bearing capacity factor always fluctuates up and down near a certain value,and the greater the buried depth is,the smaller the fluctuation degree is;The more the loading direction deviates from the vertical direction of the anchor axis,the smaller the end bearing capacity factor is;When the embedment depth,relative density and orientation are fixed,the bearing area always affects the end resistance bearing coefficient in a very similar pattern under different loading directions.Finally,the explicit expression of end-bearing capacity factor is obtained by multivariate function fitting method,and its applicability and accuracy are verified by a large number of cases and orthogonal tests.