Mechanical behaviors of hydrate-bearing sediment with different cementation spatial distributions at microscales

Unlike the conceptual models, the natural hydrate spatial distribution in sediments is multitype and presents different coalescence degrees. In this study, we present pore-scale triaxial test results for hydrate-bearing sediments with different hydrate spatial distributions for the first time. It shows that the specimen with a more dispersed hydrate distribution yields later and exhibits larger peak strength. Correspondingly, the localized deformation develops more slowly, and the shear band is steeper and thinner. The cementation failure in the specimen with a more dispersed hydrate distribution develops more slowly. However, the changing rate of the pore space characteristic does not seem to be affected by the hydrate spatial distribution. Moreover, the specimen with a more dispersed hydrate distribution has a larger hydrate-sand interfacial area, and further axial loading would increase it rapidly firstly, and then the increasing rate would be slowed down since the cementation structure failure.