Effect of Loading Rate on the Uplift Capacity of Plate Anchors

摘要

The plate anchor is a relatively new offshore foundation to moor large floating structures in deep water. The behaviour of strip plate anchors for various loading rates is studied using a large deformation finite element method for coupled geotechnical problems. The normally consolidated clay in the seabed is described with the modified Cam-clay constitutive model. The procedure of large deformation analysis developed avoids severe distortion of soil elements, therefore, it can derive the uplift capacity and distribution of excess pore pressures against the significant displacement of anchors. It is found the mobilised capacity may decrease with increasing moving velocity of anchors until the velocity approaches a critical value. This critical velocity represents the undrained condition. Compared with total stress analyses, the uplift capacity factor from coupled analyses is a little higher due to plastic hardening of soil above the plate.