Mechanical properties of sand, silt, and clay containing tetrahydrofuran hydrate

• Published in: Journal of Geophysical Research - Solid Earth Vol. 112; no. B4; pp. B04106 - n/a
• Main Authors: Yun, T. S., Santamarina, J. C., Ruppel, C.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Geophysical Union 01-04-2007; Blackwell Publishing Ltd
• Subjects: Earth sciences; Earth, ocean, space; elasticity; Elasticity and anelasticity; Exact sciences and technology; Fracture and flow; Gas and hydrate systems; Gas hydrate; Hydrology; Ices; Marine Geology and Geophysics; mechanical behavior; Mineral Physics; Physical Properties of Rocks; Planetary Sciences; sediment strength; Soils; Solid Surface Planets; stiffness; Gas hydrate; sediment strength; stiffness; elasticity; mechanical behavior; shear strength; Particle size; strength; triaxial tests; slopes; specific surface; Stress strain; clay; coordination; confining pressure; particles; soils; stability; clastic rocks; strain; Complex function; cementation; hydrates; concentration; drilling; silt; velocity; mechanical properties; sedimentary rocks; sand
• ISSN: 0148-0227; 2156-2202
• DOI: 10.1029/2006JB004484

The mechanical behavior of hydrate‐bearing sediments subjected to large strains has relevance for the stability of the seafloor and submarine slopes, drilling and coring operations, and the analysis of certain small‐strain properties of these sediments (for example, seismic velocities). This study reports on the results of comprehensive axial compression triaxial tests conducted at up to 1 MPa confining pressure on sand, crushed silt, precipitated silt, and clay specimens with closely controlled concentrations of synthetic hydrate. The results show that the stress‐strain behavior of hydrate‐bearing sediments is a complex function of particle size, confining pressure, and hydrate concentration. The mechanical properties of hydrate‐bearing sediments at low hydrate concentration (probably < 40% of pore space) appear to be determined by stress‐dependent soil stiffness and strength. At high hydrate concentrations (>50% of pore space), the behavior becomes more independent of stress because the hydrates control both stiffness and strength and possibly the dilative tendency of sediments by effectively increasing interparticle coordination, cementing particles together, and filling the pore space. The cementation contribution to the shear strength of hydrate‐bearing sediments decreases with increasing specific surface of soil minerals. The lower the effective confining stress, the greater the impact of hydrate formation on normalized strength.