Study of mechanism and theoretical model of seabed destruction caused by gas hydrate dissociation. Issue 3 (4th March 2021)

• Record Type: Journal Article
• Authors: Yang, Xiuqing; Guo, Lei; Zhou, Lei; Lu, Yueyue; Liu, Tao
• Is Part Of: Marine georesources & geotechnology. Volume 39:Issue 3(2021)
• Page Start: 343
• Page End: 353
• Publication Date: 2021-03-04
• Subjects: Gas hydrate decomposition -- excess pore pressure ratio -- excess pore pressure -- slope stability -- failure mechanism; Marine mineral resources -- Periodicals; 551.46
• DOI: 10.1080/1064119X.2019.1701590
• Languages: English
• ISSNs: 1064-119X

Abstract

Abstract: Gas hydrate decomposition is an important cause of submarine geological hazards. Understanding the mechanism of overlying seabed failure caused by gas hydrate decomposition is important to engineering practice and geological hazard prediction. In this paper, an observational device is designed to simulate the process of seabed failure caused by gas hydrate decomposition and the evolutionary process of seabed failure under different seabed thickness and slope conditions is compared and analysed. The mechanism of seabed damage is also discussed. In addition, based on the seabed failure mechanism, a computational model for the influence of hydrate dissociation on seabed stability is established. It is found that in shallow or steeper strata, the seabed will be destroyed by shear slip; however, when the stratum is thicker or the slope is gentle, the seabed surface first collapses, then is deformed and destroyed. The excess pore pressure ratio of the seabed in critical failure state is only related to the seabed gradient. The larger the gradient, the smaller the critical excess pore pressure ratio.