Constitutive model of sand considering complex stress paths
砂土的应力路径本构模型

The relativity of stress path is an important mechanical behavior of soils. In this paper, by the means of equivalently approaching the infinitesimal of stress path, it is decomposed into two parts, one of which is in the infinitesimal of constant hydrostatic pressure and the other is in the infinitesimal of constant ratio of shear stress to hydrostatic pressure. The plastic strain, which is caused in random stress paths under loading conditions, can be calculated easily by using this method. According to this idea, we propose a constitutive model of sand, which can consider the influence of stress path. There are two linear yield surfaces in p-q plane. The loading criterion is easily determined based on these yielding surfaces. Using transformed stress method, it is easy and reasonable to combine the model with the Generalized Non-linear Strength Theory to make the model describe complex stress states. The model can rationally describe the characteristics of deformation and strength of sand under various stress paths.