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水合物含量、有效围压是影响含天然气水合物沉积物力学性质的主要因素,在忽略其他次要因素(包括水合物种类、试样颗粒大小、试验条件等)的情况下,水合物含量和有效围压是决定试样弹性模量的两个关键参数。在分析等效弹性模量与水合物含量相互关系的基础上,考虑有效围压的影响,建立了弹性模量与有效围压的幂函数关系;同时采用Drucker-Prager破坏准则来表示含天然气水合物沉积物微元强度,并假设其微元强度服从Weibull分布,从而建立了含天然气水合物沉积物的损伤统计本构模型,与不同有效围压下的试验结果及已有研究成果相比较,表明了所建模型能够很好地模拟三轴剪切条件下含水合物沉积物试样的应力-应变关系特性。此研究成果可对含天然气水合物沉积物工程性状的数值模拟提供参考。
Hydrate content and effective confining pressure are the main factors affecting the mechanical properties of gas hydrate-bearing sediments. Ignoring other secondary factors (including hydrate species, sample particle size, test conditions, etc.), the hydrate content and Effective confining pressure is the two key parameters that determine the modulus of elasticity of the specimen. Based on the analysis of the relationship between equivalent elastic modulus and hydrate content, considering the influence of effective confining pressure, the relation between elastic modulus and effective confining pressure is established. At the same time, Drucker-Prager failure criterion is used to represent the effect of gas hydration The micro-element strength of the sediment is assumed to be obeyed by the Weibull distribution. Therefore, the statistical constitutive model of the damage of gas hydrate deposits is established. Compared with the experimental results under different effective confining pressures and the existing research results, It is shown that the model can well simulate the stress-strain relationship of hydrate-bearing sediment samples under triaxial shear. The results of this study can provide references for the numerical simulation of engineering properties of gas hydrate-bearing sediments.