InterPore2026

Effect of Gas Hydrate Dissociation on the Bearing Capacity of Suction Caisson Foundations for Offshore Energy Development

19 May 2026, 14:35

15m

Oral Presentation (MS16) Complex fluid and Fluid-Solid-Thermal coupled process in porous media: Modeling and Experiment MS16

Speaker

Prof. Bisheng Wu (China University of Petroleum (Beijing))

Description

Suction caisson foundations are widely used in deep-sea oil and gas development and offshore wind power projects due to their high construction efficiency and excellent load-bearing capacity. Natural gas hydrates are widely found in deep-sea sediments and are prone to dissociation under engineering disturbances and temperature and pressure changes, leading to increased sediment pore pressure, structural damage, and deterioration of mechanical properties, which significantly affects the load-bearing capacity and stability of SCFs. This paper focuses on SCFs in natural gas hydrate-containing sediments, systematically studying the evolution of soil mechanical properties during hydrate dissociation and its impact on foundation load-bearing capacity. Based on the thermo-hydro-mechanical multiphysics coupling theory, a suction caisson-soil interaction analysis model considering the hydrate phase transition effect is established, focusing on analyzing the variation laws of vertical, horizontal, and uplift load-bearing capacity of SCFs under different hydrate saturation, dissociation degree, and dissociation range conditions. The results show that hydrate dissociation significantly reduces the shear strength and stiffness of the soil, weakens the side resistance of the caisson wall and the load-bearing capacity of the caisson bottom, leading to increased foundation deformation and a significant decrease in load-bearing capacity; the adverse effects are particularly significant when the dissociation zone is located near the caisson wall or the caisson bottom region. The spatial distribution and evolution of hydrate dissociation are key factors controlling the safety of SCFs. The research findings can provide theoretical basis and technical support for the design optimization, construction control, and safety assessment of SCFs in deep-sea hydrate-bearing areas.