Analysis of Stress-Strain Behavior And Constitutive Relation of Methane Hydrate-Bearing Sediments With Various Porosity

To study the stress-strain behavior of methane hydrate-bearing sediments with various porosity that was tremendously affected by environmental conditions a series of triaxial tests was performed using artificial samples of methane hydratebearing sediments under various conditions with confining pressures (P ) at 2.5, 3.75 and 5 MPa, temperatures (ˆ) at −5C, −10C and −20C, and strain rates at 0.1, 0.5 and 1%/min. The variation of deviator stress with axial strain was observed, and the strain type was analyzed systematically under different experimental conditions. In addition, based on the experimental and analysis results of the stress-strain behavior of triaxial tests, this paper proposes the modified nonlinear elastic Duncan-Chang constitutive model, whose coefficients contain the main factors affecting stress-strain behavior.