Although cylindrical cavity expansion under plane stress condition is commonly encountered in geotechnical problems, most currently available solutions have been developed for cavity expansion under plane strain condition. This paper develops a novel elastoplastic solution for undrained expansion of a cylindrical cavity in SANICLAY under plane stress condition. The SANICLAY model, which could well represent the mechanical behaviour of the anisotropic soil and overconsolidated soil, is employed in the present solution to model the responses of the soil around the expanded cavity. The problem is formulated as a system of first-order differential equations with the unknown variables as the functions of an auxiliary coordinate, which are solved as an initial value problem. The expansion responses under plane stress condition are comprehensively compared with those under plane stress condition to highlight the unique expansion responses under plane stress condition. The results show that the present solution could well reflect the unique expansion responses under plane stress condition, which are totally different from those under plane strain condition. It is expected the proposed solution could provide a reasonable approach to interpret the pressuremeter test and model pile installation effects near the surface of the natural anisotropic clays.

尽管在岩土工程问题中通常遇到在平面应力条件下的圆柱形空腔膨胀，但是已经开发出了大多数当前可用的解决方案来在平面应变条件下进行空腔扩张。本文提出了一种新的弹塑性解决方案，用于平面应力条件下SANICLAY中圆柱腔的不排水膨胀。在本解决方案中，采用了SANICLAY模型，该模型可以很好地表示各向异性土和超固结土的力学行为，以对膨胀腔周围的土的响应进行建模。该问题被表述为一阶微分方程组，其中未知变量作为辅助坐标的函数，并作为初始值问题求解。将平面应力条件下的扩展响应与平面应力条件下的扩展响应进行了全面比较，以突出平面应力条件下的独特扩展响应。结果表明，该解决方案能够很好地反映平面应力条件下的独特膨胀响应，这与平面应变条件下的完全不同。可以预期，提出的解决方案将为解释压力计测试和模拟天然各向异性粘土表面附近的桩安装效果提供合理的方法。与平面应变条件下的完全不同。可以预期，提出的解决方案将为解释压力计测试和模拟天然各向异性粘土表面附近的桩安装效果提供合理的方法。与平面应变条件下的完全不同。可以预期，提出的解决方案将为解释压力计测试和模拟天然各向异性粘土表面附近的桩安装效果提供合理的方法。