DEM analyses of cemented hydrate’s effect on the compression behavior of fine-grained sediments

Abstract

The participation of gas hydrate constitutionally affects the mechanical properties of gas hydrate-bearing sediments. The hydrates contribute to the mechanical properties of hydrate-bearing sediments by pore-filling, bearing and bonding effects. A discrete element model of hydrate-bearing silt was established randomly filled by the hydrate particles into silt-sized granular skeleton reservoir. The cluster & bonding hydrate is generated in the pores of the numerical silt reservoir to study hydrate’s mechanical effects. One-dimensional loading was applied to the numerical sample to investigate its volume change, bond degradation and stress transmission. The main conclusions are as follows. The structural yield stress corresponds with the abrupt bond breakage. Particles and contacts will be redistributed after the widespread bond breakage. The breakage of hydrate-hydrate bonded contacts is more quickly than that of silt-hydrate contacts ascribe to a crushing process of hydrate clusters (especially for SMH=45%).