Analytical–Empirical Approach for Estimating Kinematic-Response Relationships between Hydrate-Bearing Soils and Standard Soils

Methane hydrate within a soil pore space may significantly modify the mechanical behavior of the sediment. Previous studies have shown that the influence of hydrate on methane-hydrate-bearing sediments (MHBS) is dilative through pore-scale kinematic constraining, which in turn affects mechanical properties such as strength and stiffness. This paper presents a new analytical–empirical approach for evaluating kinematic aspects of MHBS. The suggested approach incorporates explicit experimental kinematics data of the host soil together with an analytical amplification factor. Based on known stress-dilatancy expressions, this analytical factor is found with a strong relation to stress ratios of MHBS to host soil during mechanical testing. A stress ratio model is suggested, which is developed based on a thorough study of various stress ratios from test results of both artificial and natural methane-hydrate-bearing sediments from different works. Using the suggested approach, mechanical models may consist of fewer model parameters, which may increase the model efficiency and yield a deeper understanding of fundamental mechanical characteristics of MHBS.