According to the constant water content test results on the unsaturated natural loess carried out in China,the macro constitutive model for unsaturated natural loess,which can reflect the structure and water sensitivity of intact loess,is established based on the Barcelona model and the mechanical response of model in the isotropic compression test with triaxial shear test verified by comparing with the law of laboratory test results.The results indicate that the model can reflect the character that the consolidation lines of different water contents in isotropic tests are like each other before the yield stress and the compression lines tend to coincide after yield stress.The model can also reflect that the elastic modulus decreases first and then increases with the increase of confining pressure and the path in the e-lgp space tend to turn obviously at a low confining pressure for the middle water content samples in compression triaxial tests.The model has 11 parameters,all of which can be obtained by constant water content tests.%基于国内通常进行的非饱和原状黄土等含水率试验规律,在Barcelona模型基础上,建立了考虑非饱和原状黄土结构性和水敏性两个主要特性的本构模型,并检验了等含水率等向压缩试验和三轴压缩试验中该模型的力学响应.结果表明该模型能反映等向压缩试验中不同含水率试样在结构屈服应力之前压缩线趋向重合,屈服应力之后压缩线相互趋近的特性;中等含水率试样三轴压缩试验中初始弹性模量随着围压先减少后增大的特性,e-lgp空间路径在低围压情况呈现明显转折的现象.模型共11个参数,均能从国内常用的等含水率试验获取.
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