Indexed by:Journal Article

Date of Publication:2011-01-01

Journal:CHINA OCEAN ENGINEERING

Included Journals:ISTIC、SCIE

Volume:25

Issue:1

Page Number:113-122

ISSN:0890-5487

Key Words:gas hydrate; mechanical properties; marine sediment; triaxial testing; safe extraction

Abstract:A triaxial system is designed with a temperature range from -20 degrees C to 25 degrees C and a pressure range from 0 MPa to 30 MPa in order to improve the understanding of the mechanical properties of gas hydrate-bearing sediments. The mechanical properties of synthetic gas hydrate-bearing sediments (gas hydrate-kaolin clay mixture) were measured by using current experimental apparatus. The results indicate that: (1) the failure strength of gas hydrate-bearing sediments strongly depends on the temperature. The sediment's strength increases with the decreases of temperature. (2) The maximum deviator stress increases linearly with the confining pressure at a low-pressure stage. However, it fluctuates at a high-pressure stage. (3) Maximum deviator stress increases with increasing strain rate, whereas the strain-stress curve has no tremendous change until the axial strain reaches approximately 0.5%. (4) The internal friction angles of gas hydrate-bearing sediments are not sensitive to kaolin volume ratio. The Cohesion shows a high kaolin volume ratio dependency.