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.