Prediction of Strength-Band of Methane Hydrate-Bearing Sand by Elastoplastic Constitutive Model Considering Microstructure of Gas Hydrates

In the present study, we propose a new elastoplastic constitutive equation with consideration of the hydrate morphology. Then, using the proposed constitutive equation, we investigate how large the strength and the volumetric strain change by the change in the hydrate morphology with the fixed total hydrate saturation. The result indicates that the strength and the positive dilatancy becomes the larger in the case where the morphology of the cementing-type is more dominant. Moreover, the strength curves predicted by the proposed model is in good agreement with the past experimental research. This makes it possible to predict the strength and the deformation behavior of MH-bearing sediments even in the area where there is a lack of research data.