剪正应力比综合反映了摩擦材料的变形与破坏特性。通过分析主应力的大小与方向变化所引起的剪正应力比，结合剪正应力比-剪应变分量的双曲线关系，提出了一种能考虑主应力方向的土体非线性弹性本构模型。考虑到土体初始剪切模量、各向异性峰值强度与应力历史、加载方向密切相关，给出了模型参数的取值方法，进而得到了分量形式的应力-剪应变关系。分别采用应力路径三轴试验、纯主应力轴旋转试验以及主应力方向固定的剪切试验验证了模型的合理性。预测结果与试验结果对比表明，提出的非线性弹性模型能较好地描述复杂应力路径下土体变形特性。

The ratio of shear/normal stress reflects the deformation and failure characteristics of the friction material. By analyzing the shear/normal stress ratio under the change of magnitudes and directions of principal stresses, a nonlinear elastic model of soils considering the direction of principal stress axis is proposed based on the hyperbolic relationship between the shear/normal stress ratio and shear strain component. Considering the initial shear modulus and the strength of soil are closely related to the loading history and direction of stress, a method is given to determine the parameters of the model, and then a stress-strain relationship in the form of component is obtained. The rationality of the model is validated through stress path controlled triaxial test, pure principal stress axis rotation test and shear test with fixed direction of major principal stress. Comparisons of the predictions with the experimental results show that the deformation characteristics of soils under complex stress paths can be well quantified by the proposed nonlinear elastic model.