A study on the coupling mechanism of hydrate dissociation-seepage-heat transfer induced by suction anchor installation in marine sediments

The suction anchor base has been widely used in marine engineering as an innovative and efficient foundation for marine structures. However, prior research endeavors have neglected to account for the influence of hydrate dissociation within the seabed sediments on suction anchors' negative pressure installation process. This paper elucidates the intricate coupling mechanism of hydrate dissociation, seepage, and heat transfer within marine sedimentary layers, all of which are induced by installing suction anchors. Employing a multi-physical field coupling methodology, numerical simulations were conducted to analyze the influencing factors and spatiotemporal evolution of hydrate dissociation and the impact of hydrate dissociation on seepage and pressure fields. The results indicate that the increases in negative installation pressure, penetration depth, and stratigraphic sensible heat promote hydrate dissociation. The hydrate dissociation enhances seepage, reduces the pressure gradient in the anchor, and decreases the suction anchor sinking force. Consequently, this research holds practical implications for guiding suction anchor installation within seabed characterized by buried hydrate.