Innovative Booster for Dynamic Installation of OMNI-Max Anchor in Clay: Numerical Modeling

Abstract

An innovative booster is proposed with the aim of increasing the final penetration depth of the OMNI-Max anchor in the clayey seabed with high strength gradient. The booster is attached to the tail of the OMNI-Max anchor, which is beneficial in improving both gravitational and kinetic energies of the hybrid anchor (i.e., booster + OMNI-Max anchor) during installation and can be retrieved after dynamic installation. The present study carried out two categories of large deformation numerical analyses to simulate the dynamic penetration processes of OMNI-Max anchors and hybrid anchors in normally consolidated and lightly overconsolidated clay. The coupled Eulerian–Lagrangian (CEL) approach was used to investigate the effects of impact velocity, booster weight, and soil strength characteristics (including the strain-rate behavior, the strain-softening behavior, and the undrained shear strength) on the final penetration depth of the anchor. Due to the limitations of the CEL approach in simulating the adhesion friction at the anchor–soil interface, a thin layer region method coupled in the computational fluid dynamics (CFD) approach was used to investigate the effect of the friction coefficient at the anchor–soil interface on the final penetration depth of the anchor. Based on numerical simulation results, a comprehensive prediction model based on the anchor total energy was established to rapidly predict the final penetration depth of the OMNI-Max anchor and the hybrid anchor by considering the strain-rate effect, strain-softening effect, and friction coefficient at the anchor–soil interface.