一种改进的水合物沉积物弹塑性损伤本构模型  

An improved constitutive model coupling elastoplasticity and damage for methane hydrate-bearing sediments

作　　者：杨期君[1] 赵春风[1] 

机构地区：[1]同济大学土木工程学院地下建筑与工程系岩土与地下工程教育部重点实验室,上海200092

出　　处：《海洋工程》2014年第5期57-62,92,共7页The Ocean Engineering

基　　金：国家自然科学基金资助项目(40972180)

摘　　要：为了全面考虑水合物对沉积物的力学影响,提出了一个改进的水合物沉积物弹塑性损伤本构模型。首先通过分析水合物在沉积物中的存在形式,认为沉积物的力学特性是水合物胶结以及密实两种作用共同影响的结果;然后在弹塑性损伤理论框架内,引入状态相关砂土本构模型来描述水合物填充的影响,从而建立一个能反映体变特性和围压影响的水合物沉积物本构模型;最后,利用已有试验结果对模型进行了验证。此成果可为将来的水合物开采提供参考。To consider the mechanical influence of methane hydrate comprehensively, this paper presents an improved constitutive model coupling the elastoplasticity and damage for methane hydrate-bearing sediments （HBS）. Based on the detailed analysis of the hydrate distribution in the sediments, it is assumed that the mechanical properties of HBS are influenced by both the cementation and the densification of methane hydrate. A state-dependant constitutive model for sand is then introduced for describing the influence of the pore-filling hydrate. Consequently, a constitutive model for HBS is developed. Finally, the proposed model is validated by the experiment results obtained from triaxial tests on synthetic HBS. The research results can provide references for the extraction of methane hydrate in the future.

关 键 词：水合物沉积物 本构模型 状态相关 摩擦 胶结 损伤 

分 类 号：TU457[建筑科学—岩土工程]