Embedment Characteristics Of The Installation Line For Drag Anchors In Seabed Soils

As the exploitation of the marine hydrocarbon resource extending to deep and ultra-deep waters, new-type drag anchors are widely used in deepwater engineering. Exactly positioning of drag anchors is a key problem in the field application, and is closely related to the embedment characteristics of the installation line. Study on the embedment characteristics of the drag line is significant to the exactly positioning and optimization of installation techniques for drag anchors.The anchor is gradually penetrated into soils due to the drag force transmitted from the installation line; the variational property of the length of the embedded line is the main embedment characteristic. Herein, based on the pre-existing expression of the length of the embedded line, taking into account the model for kinematic trajectory of drag anchors, the equations and their simplifications of the length of the embedded line as well as some deduction are derived for both cohesive and noncohesive soils. A parametric analysis is performed systematically to study the effects of several key parameters, and the precision of the simplifications is checked respectively.Considering the diameter of the drag line, the difference between embedment points on the top and bottom faces of the line are proposed and the transformation method between them are derived. A visual tracking technique is adopted to get the variations of the length of the embedded line by tracking the movement of the embedment point on the top face and transformation to the embedment point on the bottom face of the line, and model experiments are performed as a verification of the analytical model. The result indicates that the analytical model can forecast the variations of the length of the embedded line to a certain extent.