【摘要】 以中国近海某天然气水合物(水合物)区的海底粉质黏土制备水合物沉积物样品,并在土工三轴仪上进行实验,分析其应力应变曲线和破坏应力特性。结果表明:力学常数如破坏应力(应变为15%对应的偏应力)随水合物饱和度的增加而增加,在饱和度约25%时破坏应力产生跳跃,即破坏应力随水合物饱和度的变化可分为两部分,饱和度小于25%时水合物的存在对沉积物破坏应力影响较小,大于25%时影响较大。在水合物饱和度小于45%的范围内,水合物沉积物的应力应变曲线可分为弹性段、屈服段和强化段。文中给出了描述其应力应变曲线的分段函数。更多还原

【Abstract】 Triaxial tests were carried out to study the stress-strain characteristics of tetra-hydro-furan(THF)hydrate-bearing sediment by using the silty-clay sampled as skeleton from China’s offshore area.It is shown that the failure stresses(the variational stress at strain 15%)increase with hydrate saturation and there a jump at strain 25%.In other words,the relation between failure stress and saturation can be divided into two stages:the effects of hydrate saturation are small when the strain is less than25% while it is large at strain exceeding 25%.The strain-strain curve can be divided into three stages:elastic stage,failure stage and strengthening stage.A subsection function is used to describe the stressstrain curve.The stress-strain curve can be divided into three stages:linear stage,failure stage and strengthening stage at strain 0~45%.Piecewise function was used to describe the relation.更多还原