The Distinct Elemental Analysis of the Microstructural Evolution of a Methane Hydrate Specimen under Cyclic Loading Conditions.

Submarine slope instability may be triggered by earthquakes and tsunamis. Methane hydrate sediments (MHS) are commonly buried under submarine slopes. Submarine slides would probably be triggered once the MHS are damaged under cyclic loading conditions. For this reason, it is essential to research the mechanical response of MHSs under dynamic loading conditions. In this study, a series of drained cyclic biaxial compressive tests with constant stress amplitudes were numerically carried out with the distinct element method (DEM). The cyclic loading number decreased as the hydrate saturation (Sh) increased when the MHS were damaged. The failure mode of the MHS was shown to be dependent on the dynamic stress amplitude and hydrate saturation. The microstructure of MHS during the cyclic loading shear process was also analyzed. The results can help us to understand the mechanical behavior of MHS during the cyclic loading process and develop micromechanical-based constitutive models. [ABSTRACT FROM AUTHOR]