The role of shared suction anchors for mitigating cascading failure in floating offshore wind farms

Abstract

Shared anchors offer significant potential for reducing mooring costs and enhancing floating wind competitiveness, yet industry adoption remains hindered by cascading failure risks in multi-anchor configurations. Critical research gaps persist regarding the initiation mechanisms, propagation dynamics, and mitigation strategies for such failures in shared-anchor floating wind farms. This study addresses these gaps through a novel systematic methodology that derives shared suction anchor loading conditions using inverted catenary theory. Contrary to conventional assumptions, the analysis reveals that multi-line suction anchors exhibit no mechanical superiority over conventional foundations. Instead, they demonstrate less rational force distribution and greater failure susceptibility under environmental loading. Following initial anchor failure, platform displacement in shared-anchor wind farm decreases by 80% relative to conventional floating wind farms using strengthened chains, but the peak tension rises to 1.25 times owing to the dynamic amplification effect. Although variations in soil capacity affect mooring chain inclination angles, 3-line anchors remain most prone to initial failure across all soil conditions. After the initial failure of adjacent anchors, the susceptibility to secondary failure of 3-line anchors markedly decreases in stiffer soils. To prevent cascading failures, suction anchor designs must satisfy dual safety criteria: withstand intact-system loads and accommodate post-initial-failure amplified secondary anchor loads.