Mechanical behavior of gas‐saturated methane hydrate‐bearing sediments

Abstract

Abstract A series of triaxial compression tests were conducted in order to investigate the mechanical behavior of gas‐saturated methane hydrate‐bearing sediments, and a comparison was made between gas‐saturated and water‐saturated specimens. Measurements on gas‐saturated specimens indicate that (1) the larger the methane hydrate saturation, the larger the failure strength and the more apparent the shear dilation behavior; (2) failure strength and stiffness increase with increasing effective confining stress and pore pressure applied during compression, though the specimen becomes less dilative under higher effective confining stress; (3) lower temperatures lead to an increase of the stiffness and failure strength; (4) stiffness of specimens formed under lower pore pressure is higher than that of specimens formed under higher pore pressure but at the same effective stress; (5) stiffness and failure strength of gas‐saturated specimens are higher than those of water‐saturated specimens; (6) gas‐saturated specimens show more apparent strain‐softening behavior and larger volumetric strain than that of water‐saturated specimens.