Recovery length in sheathed spiral strands in deep-water platform applications

A theoretical model is presented for predicting the recovery length in any layer of an axially pre-loaded sheathed spiral strand experiencing external hydrostatic pressure. Based on a series of theoretical parametric studies, a straightforward method is proposed for obtaining reasonable estimates of variations in the recovery length in air for any layer of a strand with changes in the lay angle. Numerical results show that the magnitude of recovery length in sheathed spiral strands can be reduced substantially by subjecting the strand to high levels of external hydrostatic pressure, with the lay angle and (to a lesser extent) the strand mean axial load having some influence on the estimates of recovery length.