考虑时间效应的K_0各向异性UH模型

将所建立的考虑时间效应的超固结土统一硬化模型(时间UH模型)推广为能够考虑K0各向异性的弹黏塑性模型。基于广义非线性强度准则的变换应力三维化方法,将新模型扩展到三维应力状态。使用新模型预测K0固结土的一维和三轴等应变率加载试验,预测结果表明新模型能够合理反映应变率对K0固结土前期固结压力和应力应变曲线的影响。根据模型的基本方程,推导三轴压缩条件下不排水抗剪强度的理论公式,并将该公式的计算结果与试验结果进行对比,发现该公式能够反映不排水抗剪强度随超固结度和应变率的增大而提高的性质。

K0-anisotropic UH model considering time effects

The time-dependent unified hardening constitutive model for overconsolidated clays (time-dependent UH model) proposed by the authors is extended to a constitutive model considering K₀-anisotropy. Based on the generalized non-linear strength criterion and the corresponding transformed stress tensor, the new model is generalized to the three-dimensional stress state. The new model is then used to predict one-dimensional and triaxial CRS (constant rate of strain) tests on K₀-consolidated clays. The predicted results indicate that the new model can reflect reasonably the influence of strain rate on preconsolidation pressure and stress-strain relationship of K₀-consolidated clays. Moreover, a theoretical function of triaxial undrained shear strength is deduced from basic equations of the new model. The calculated results of the theoretical function are compared with the experimental ones, and it is shown that the theoretical function can describe the experimental phenomenon that triaxial undrained strength increases with the increasing overconsolidation degree or the strain rate.