中文摘要：

水合物含量和水合物赋存模式都会对含水合物沉积物的力学特性产生影响，但目前的本构模型很少考虑水合物赋存模式的影响。在分析水合物赋存模式对含水合物沉积物力学特性影响机制的基础上，提出了采用有效水合物饱和度来描述水合物赋存模式对沉积物力学特性的影响。基于前人建立的含水合物沉积物的统计损伤本构模型，假设含水合物沉积物微元强度服从Weibull分布，采用Drucker-Prager强度准则描述微元强度，建立了考虑水合物赋存模式影响的含水合物沉积物的统计损伤本构模型。该模型修正了水合物含量和试验围压对弹性模型的影响关系式，并且建立了模型参数m和F0与水合物饱和度Sh和试验围压σ3之间的关系。通过与试验数据的对比，说明该模型能很好地模拟含水合物沉积物的应力一应变关系，反映水合物含量和水合物赋存模式对含水合物沉积物的刚度、强度、应变软化等力学特性的影响规律。

英文摘要：

Not only hydrate amount but also occurrence habits of hydrate in sediments influence the mechanical characteristics of gas hydrate-bearing sediments （GHBS）. In constitutive models proposed recently, however, the influence of occurrence habits is not considered. Based upon the influence mechanism of occurrence habits of hydrate on mechanical behaviors of GHBS, a novel concept, called effective saturation of hydrate, is proposed to address the influence of occurrence habit of hydrate. Referring to the statistical damage constitutive model for GHBS by previous researchers, a statistical damage constitutive model considering occurrence habits of hydrate is developed. In this model, the strengths of microelements for GHBS are assumed to obey the Weibull distribution, and the strength of microelement is calculated using the Drucker-Prager strength criterion. A modified empirical formula of elastic modulus is suggested to consider the effect of hydrate saturation and testing confining pressure. Meanwhile, the relationships between model parameters m and F0, hydrate saturation sh and confining pressureσ3 are analyzed; then the fitting expressions are furtherly proposed. Finally, it is demonstrated that this model can simulate well the stress-strain curves of GHBS, and has capacity of reflecting the stiffness, strength and softening, characteristics of GHBS.