Drucker-Prager elasto-plastic constitutive model for methane hydrate-bearing sediment

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• 作者：Xiang Sun 孙 翔 ; Xiaoxia Guo 郭晓霞 ; Longtan Shao 邵龙潭…
• 关键词：constitutive model ; methane hydrate ; bearing sediment ; yield surface ; bonding
• 刊名：Transactions of Tianjin University
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：22
• 期：5
• 页码：441-450
• 全文大小：1,165 KB
• 刊物类别：Engineering
• 刊物主题：Chinese Library of Science
  
• 出版者：Tianjin University
• ISSN：1995-8196
• 卷排序：22

文摘

A constitutive model for methane hydrate-bearing sediment(MHBS)is essential for the analysis of mechanical response of MHBS to the change of hydrate saturation caused by gas extraction. A new elasto-plastic constitutive model is built in order to simulate the mechanical behavior of MHBS in this paper. This model represents more significant mechanical properties of MHBS such as bonding, higher stiffness, softening and stress-strain nonlinear relationship. The bonding behavior can be described by use of a parameter related to mechanical hydrate saturation. Higher stiffness can be modeled by the introduction of hydrate saturation into traditional expression of soil stiffness. Softening can be controlled by a function describing the relationship between cohesion and bonding structure factor. Dilatancy can be estimated by establishing the relationship between the lateral strain and axial strain. Meanwhile, the hypothesis of isotropic expanding is applied to the calculation of the volumetric strain. The stress-strain curves under different hydrate saturation conditions predicted by the proposed model are in good agreement with the test data. All the coefficients can be easily obtained by the triaxial test of MHBS.