Dynamics of a taut mooring line accounting for the embedded anchor chains

Mooring line responses have been widely analyzed in the past three decades. Most of these studies have assumed that the anchor point is fixed at the seabed. However, with the increasingly employment of the taut mooring system, the suction anchors are more and more often used. To achieve an appropriate hold capacity, the anchor points are embedded several meters beneath the seabed, making part of the mooring lines embedded, whereby complex soil-chain interaction occurs. The soil-chain interaction has not been incorporated in previous mooring dynamic analyses. In this study, a dynamic method using the lumped mass model was used to consider the soil-chain interaction for the embedded anchor chain. Validation has been conducted against both analytical results and those from the commercial code. To clarify the influence of the embedded chain, case studies were conducted to compare the line's dynamic response at the anchor point, touchdown point and fairlead in three different configurations. Recommendations have been given on two frequently-used in simplifying the mooring dynamic calculation.