Discrete element modelling of geomechanical behaviour of methane hydrate soils with pore-filling hydrate distribution

Methane hydrate soil is a natural soil deposit that contains methane hydrate in its pores. The micro-scale processes of the geomechanical behaviour of methane hydrate-bearing soils are investigated by the Discrete Element method (DEM). A series of DEM simulations of triaxial compression tests were performed to study the influence of methane hydrate saturation (S (h) ) on the stress-strain relationship, the volumetric response and on the macroscopic geomechanical properties such as friction and dilation angle. Results of the numerical simulations are compared with laboratory triaxial test data performed on sandy methane hydrate samples. The simulations showed that for the pore-filling case, the hydrate contribution to the strength of the sediment is of a frictional nature, rather than of a cohesive nature.