DEM Analysis of Geomechanical Properties of Cemented Methane Hydrate–Bearing Soils at Different Temperatures and Pressures

Abstract

AbstractMechanical properties of methane hydrate–bearing soils are influenced by the surrounding temperature and pore pressure. Studies of such influences are of great significance for the safe exploration of methane hydrate. First, a thermo-hydro-mechanical bond contact model is introduced to elucidate the microscopic contact scale behavior of grains with methane hydrate bonds. Second, such a model is incorporated into the distinct-element method (DEM), and a dimensionless temperature-pressure distance parameter is introduced. The influences of temperature and pore pressure along heating and depressurization paths are analyzed by conducting DEM biaxial compression tests, which are also compared with the results of laboratory triaxial compression tests conducted by others. The variation rules of the macromechanical properties (i.e., strength, elastic modulus, peak friction angle, cohesion, and dilatancy angle) with changing temperatures and pore pressures are then analyzed for different effective confinin...