Strain Rate-Dependent Mechanical Response of Hydrate-Bearing Sediments under Plane Strain Condition

• Published in: Journal of Marine Science and Engineering
• Main Authors: Qi Wu, Yingjie Zhao, Norimasa Yoshimoto, Jinan Guan, Yukio Nakata, Shintaro Kajiyama, Masayuki Hyodo
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2023
• Subjects: methane hydrate; strain rate-dependent; fine particles; hydrate saturation; particle tracking velocimetry; Naval architecture. Shipbuilding. Marine engineering; VM1-989; Oceanography; GC1-1581; Methane hydrate
• Online Access: https://doi.org/10.3390/jmse11061161; https://doaj.org/article/e89a69fb757d493f958b37ddeaa9c4c0

Natural gas hydrate has gained significant attention in recent years. To safely and sustainably exploit the natural gas from gas hydrate-bearing sediments, it is crucial to understand the long-term mechanical characteristics of the hydrate reservoir. In this study, the influence of hydrate and fine particles on the strain rate dependence of hydrate-bearing sediments under plane strain conditions has been studied. The experimental results show that the strain rate dependency of the mechanical properties of hydrate-bearing sediments is positively correlated with hydrate saturation instead of the morphology of hydrate in sediments. The residual strength of hydrate-bearing sediments is primarily controlled by the hydrate saturation and is independent of the strain rate. Changes in hydrate saturation and fines content can affect the relationship between the strain rate and shear band angle. Finally, the local volumetric expansion effect of hydrate-bearing sediments without fines content is more significant and shows a strong strain rate dependence characteristic. Overall, this study provides valuable insights into the long-term mechanical characteristics of hydrate reservoirs. These insights can contribute to the development of a constitutive model of hydrate-bearing sediments with time dependence in the future, which is meaningful to the exploitation of natural gas hydrate.