A triaxial system is designed with a temperature range from -20 ℃ to 25℃ 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....A triaxial system is designed with a temperature range from -20 ℃ to 25℃ 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.展开更多
基金supported by the National High Technology Research and Development Program of China(863 Program,Grant No. 2006AA09A209)the Major National S&T Program(Grant No. 2008ZX05026-004)+1 种基金the Major State Basic Research Development Program of China(973 Program,Grant No. 2009CB219507)the National Natural Science Foundation of China(Grant No.91010015)
文摘A triaxial system is designed with a temperature range from -20 ℃ to 25℃ 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.
