Centrifugal Model Test And CEL Simulations On The Installation Process Of Vertically Loaded Anchor

As an important part of deep-sea mooring system,vertically loaded anchors(VLAs)with a bridle shank are widely used in practice.But in actual engineering,the trajectory of normal VLAs cannot be well predicted.In addition,the shank dimension has a great influence on the trajectory and installation load of VLAs.In this paper,a new trajectory measurement method is proposed using a wire displacement sensor and an acceleration sensor,which realizes the realtime measurement of the trajectory in the centrifuge model test.The measuring method is verified by some specific centrifuge tests.Moreover,the installation load was measured using the Load-Cell axial force sensor.The anchor model used in this paper is a Stevmanta-style anchor.During the centrifugal model test,the front and rear bridle ratios were changed to 0.45,0.67,0.74,and 1.57 to study the effects on trajectory and installation load.The test results show that when the bridle ratio increased from 0.45 to 0.67,the corresponding horizontal drag distance increased from 367.38 mm to 575.56 mm,and the penetration depth increased from 48.96 mm to 154.8mm,;when the bridle ratio increased from 0.64 to 0.74,the corresponding horizontal drag distance increased from 575.56 mm to 582.45 mm,and penetration depth increased from 154.8mm to 170.2mm.In addition,the change of the inclination angle of the fluke increased with the increase of the dragging distance,and the installation load also changed with the ratio of the front and rear anchor shank ratio.In general,the greater the bridle ratio is,the greater are the penetration depth and the installation load.The test results have certain reference significance for the prediction of the actual installation of VLAs.In addition,with the help of the CEL method in the ABAQUS software,this paper calculated the trajectory of VLAs when the front to back bridle ratio is 0.7,0.8,0.9,and 1.0,taking into account the softening characteristics of the soil.It was compared with the results of the centrifugal model test.The calculation results show that with the increase of bridle ratio,the penetration depth of the anchor plate and the horizontal drag distance were also increasing.The movement curve of the anchor plate and the centrifugal model test were obtained.The form of the trajectory curve tend to be consistent.Due to the strength of the soil,the increase in penetration depth of the model anchors with different bridle ratios was greater than the increase in horizontal drag distance.