中文摘要：

天然土体的初始各向异性通常可对其后继循环特性产生显著影响。现有考虑循环载荷作用的土体弹塑性模型，往往采用类似修正剑桥模型的椭圆形屈服面，已有研究表明，该椭圆形屈服面因其拉伸弹性区域偏大，针对天然 K0固结状态的土体，其计算精度较差。基于新近提出的广义各向同性硬化准则，在边界面方程中引入初始各向异性张量，并采用空间滑动面破坏准则（SMP）的变换应力法，建立了能考虑饱和黏土初始各向异性的循环边界面塑性模型。分别针对等压和偏压固结的饱和黏土静、动三轴试验进行模拟，结果表明，该模型能合理反映土体的初始各向异性及其后继循环动力特性。

英文摘要：

The initial anisotropy of natural soft clay tends to have a significant influence on its subsequent cyclic behaviors. The current elastoplastic constitutive models for cyclic behaviors of saturated clay always adopt an elliptic yield surface similar to the one in the modified Cam-clay model. However, studies have demonstrated that these kinds of models which adopt an elliptic yield surface are not suitable for predicting the characteristics of K0-consolidated soils under the extension state, due to its over-predicted elastic region. In this paper, within the framework of the generalized isotropic hardening rule, by introducing the initial anisotropic tensor to the formation of the bounding surface and combining with the transformed stress tensors which are based on the spatially mobilized plane （SMP） yield criterion, a new bounding surface plasticity model for saturated clay with initial anisotropy is proposed. The predicted results by the model for the monotonic and cyclic triaxial tests on both isotropically and anisotropically consolidated clays demonstrate that the bounding surface model can reasonably describe the initial anisotropy and the subsequent cyclic behaviors of saturated clay.