风积土本构模型参数修正方法

Modification for Aeolian Soil Constitutive Models

目的修正邓肯-张E-B模型参数并建立新的风积土本构模型.方法采用应变控制式三轴压缩仪,通过对风积土的结构性试验研究,进行固结排水试验并引入围压损伤比的概念.结果试验通过观测围压在0.1 MPa、0.2 MPa、0.3 MPa时对风积土结构的损伤,得到考虑土体结构性影响的邓肯-张E-B模型的参数修正方法.试验中,在多组围压下发现土体内摩擦角φ值逐渐减小,黏结力C值逐渐增大;在卸载-再加载条件下,原状土的结构性被破坏.因此,将邓肯—张模型中参数C、φ、Rf、K、n、Kb、m、Kur、nur进行了修正.结论提出的围压损伤比对土体的模型参数修正方法具有一定的理论意义和实际应用价值,建立修正后的风积土本构模型为其他同类工程地区风积土工程数值计算提供了参考依据.

We Modify Duncan- Chang（E- B） Model parameters and build new Aeolian Soil constitutive models. Through research of structural experiment, consolidation drained experiment should be made by adopting strain- controlled triaxial apparatus and quotating concept of confining pressure damage rate. By observing structural damage of confining pressure at 0.1 MPa, 0.2 MPa, 0,3 MPa, the modified Duncan - Chang（E- B） Model parameters including soil structural effects are obtained. In the process of experiment, value of internal frictional angle decreases while the value of cohesive strength C increases under different confining pressure; under the condition of download - upload, structure of. undisturbed soil has been damaged. So parameters of C, φ, Rf, K, n, Kb, m , Kur, nurin Duncan - Chang（E - B） Model are modified. Thus, Introducing the concept of confining pressure damage rate has both theoretical and practical value for modification of model parameters. Aeolian Soil constitutive models built after modification can provide reference for caculation of Aeolian Soil engineering in other similar engineering regions.