在我国的一些有关基坑工程的规范中,对于饱和软黏土地基的抗剪强度,规定采用“有效自重压力下预固结后的三轴不排水试验”确定,原位地基土处于静止土压力状态(K0状态),而常规三轴试验是各向等压固结,这种各向等压固结压力与原位的K0状态固结压力如何对应,以使强度指标一致,是本文讨论的问题。文中根据剑桥模型的物态边界面的概念和模型的加卸载准则,得出了二者的平均主应力应当相等的结论,这对于在设计中正确确定和选用强度指标是十分重要的。 In some specifications of foundation pit engineering in our country, for the shear strength of saturated soft clay foundation, the “three-axis undrained test after pre-consolidation under effective self-weight pressure” is stipulated, and the in situ foundation soil is at rest Earth pressure state (K0 state), and the conventional triaxial test is the isotropic pressure consolidation, the isostatically equalizing consolidation pressure and the K0 state of the consolidation pressure in situ how to make the same intensity index is Questions to discuss. According to the concept of modal boundary of Cambridge model and the loading and unloading criterion of the model, it is concluded that the average principal stress of the two should be equal, which is very important for the correct determination and selection of the strength index in the design.