复杂应力条件下土的结构性本构关系

结合陕西杨凌非饱和黄土不同条件下的三轴试验资料，将作者提出的一种新的土结构性定量化参数（应变型综合结构势）引入土的强度变形特性分析，发现在同一围压下土结构性参数对不同影响因素下的应力应变曲线均具有较好的归一化作用。基于归一化曲线所表现出的双曲线特征，用类似邓肯一张模型的处理手法构造了非饱和黄土的结构性本构关系，本构模型的参数均可由试验确定。由于本文提出的土结构性本构关系引入了能够反映复杂应力状态的土结构性参数并且与邓肯一张模型形式相同，因而具有应用范围广泛和便于程序分析的潜力。试验验证表明，结构性本构关系可以较好地反映非饱和黄土的强度变形关系。

Structural Constitutive Relation of Soils Under Complex Stress Conditions

In this paper, a new structural parameter of soils named strain comprehensive structure potential (strain-CSP) is introduced to analyze the strength-deformation property of soils, combining with triaxial tests data of unsaturated loess under different conditions, and a better normalization effect is found in stress-strain curves of unsaturated loess with dissimilar factors influenced by structural parameter of soils at same confining pressure. Based on the hyperbolic curve feature shown in strength-deformation curves of unsaturated loess, the structural constitutive relation of unsaturated loess is constructed by using methods similar with Duncan-Chang model. All it's parameters can be confirmed from the conventional triaxial test data. Because the introduced structural parameter of soils can reflects the complex stress states and held the same pattern compared with Duncan-Chang model, the structural constitutive relation of soils presented in this paper can be widely applied to the engineering field and program analysis. The tests results show that structural constitutive relation of soils can well reflect the strength-deformation relation of unsaturated loess.