基于沈珠江双屈服面模型理论的土体弹塑性模型

Elasto Plasticity Constitutive Model of Soils Based on Shen Zhu-jiang’s Double-yield Surface Theory

摘要:

由于常用的邓肯E-μ、E-B模型的经验公式不能同时很好地反映粗粒土三轴剪切试验结果低围压剪胀、高围压剪缩变形特点，邓肯E-μ、E-B模型基于的广义虎克定律不能反映土体剪胀剪缩特性，所以笔者应用笔者发现的三轴剪切体变规律和沈珠江双屈服面模型理论相结合建立了基于沈珠江双屈服面模型理论的弹塑性模型，该模型能够很好地反映土体的剪胀剪缩特性，能够准确地拟合等围压剪切试验结果，能够很好地预测等应力比路径，等平均主应力路径，等大主应力，小主应力减小路径，小主应力和剪应力同等减小的应力路径的试验结果。

Abstract:

Empirical formula of Duncan E-μ、E-B model can not simultaneously reflect the low confining pressure dilatancy deformation and high confining pressure shear contraction deformation in coarse-grained materials tri-axial shear test, and generalized hooke’s law, on which Duncan E-μ, E-B model is based, are not able to reflect the dilatancy characteristics of soils, so a new elasto plasticity constitutive model based on Shen Zhu-jiang’s double-yield surface theory is built by means of combining the volumetric strain laws presented by writer and Shen Zhu-jiang’s double-yield surface theory. This model can well reflect the soil dilatancy characteristic, accurately fit equal confining pressure shear test results, and can predict the test results of equal stress ratio path, equal average principal stress path, equal large principal stress, minor principal stress reduction path, equal minor principal stress and shear stress reduction path and so on.