Experimental Study on Mechanical Properties of Gas Hydrate-Bearing Sediments Using Kaolin Clay

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.