Effects of Mooring-Design Parameters and Layout Configuration on the Dynamic Responses of Modular Floating Structures

Mooring systems for modular floating structures (MFSs) in shallow water require designs that account for a limited water depth, restricted footprint, and coupled responses among floaters, connectors, and mooring lines.This study aimed to identify an effective mooring design for an MFS under shallow-water constraints.Time-domain simulations were performed using OrcaFlex, and the numerical model was validated against the model test results for a 1×2 MFS with hinge and rigid connectors.Extreme loads corresponding to a 100 year return period were applied under collinear wave, wind, and current conditions.The mooring-line length, nominal diameter, spread angle, footprint, clump weight, and connector type were examined.The results showed that the maximum offset varied monotonically with the line length and diameter, whereas the maximum mooring tension exhibited a nonlinear behavior due to snap loads.A spread angle of  = 30° provided a balanced performance by limiting excessive motion and maintaining structural safety.Clump weights reduced the required footprint by up to 76%, although they slightly increased the mooring tension.The spring-fender connector reduced excessive motions and peak tensions when compared with those observed with the hinge connector.These findings support an integrated mooring-design approach for shallow-water MFSs.