The performance of the dynamically installed plate anchor in sand and silt

Abstract

Dynamically installed anchors (DIA) provide a time-efficient and cost-effective anchoring solution for offshore floating moorings. The dynamic installation and capacity mobilisation of the DIA in clayey seabed have been systematically investigated. However, the performance of the DIA in sand and silt is rarely studied. This study aims at investigating the performance of a newly proposed light-weight gravity installed plate anchor in sand and silt by conducting large deformation finite element (LDFE) analyses. Parametric studies were conducted to investigate the effects of varied factors on the final penetration depth of the anchor. By combining the present numerical results and previous experimental results, a comprehensive theoretical model was proposed for predicting the final penetration depth of the anchor in sand, silt and clay. Then the anchor-chain-soil interaction was simulated to investigate the keying behaviour of the anchor in silt, such that the motion trajectory and capacity mobilisation of the anchor could be derived. The conditions ensuring the anchor diving have been recommended.