Numerical investigation of pull-out capacity and failure mechanism of suction anchors with mooring line in sand

Abstract

Suction anchor is a widely used anchorage foundation in taut or catenary mooring systems to fix floating structures. This paper aims to investigate the pull-out capacity and failure mechanism of suction anchors in sand using the finite element method which models the attached mooring line on the anchor padeye. The advanced critical state elastoplastic constitutive model SIMSAND is utilized which can well simulate the state-dependent peak strength and stress-dilatancy behavior of sand, and its accuracy and effectiveness are validated with centrifuge test results. A series of systematical parametric studies are then carried out to explore the effects of the mooring line, aspect ratio, padeye position and loading angle on the pull-out capacity and failure mechanism of the suction anchor. Based on the numerical results and those obtained in other researchers’ work, the optimal padeye position and the normalized V–H envelopes are explicitly discussed. Finally, a calculation framework is put forward for predicting the inclined pull-out capacity of suction anchor in sand considering the mooring line effect.