【摘要】 土的结构性和应力状态是影响土力学行为的重要因素，在临界状态土力学框架内，考虑中间主应力的作用，结合统一强度理论，引入洛德角推导出统一强度参数，对临界状态线进行修正，使其能够反映不同应力状态下的临界状态。考虑结构性的影响，将其引入修正剑桥模型屈服函数中，采用非相关联流动法则，确定剪胀应力方程，建立可以反映中间主应力的结构性本构模型。采用黏性土的真三轴试验对所建立本构方程进行验证，结果表明所建立的本构模型可以较好的预测三维应力状态下的本构模型，验证了模型的合理性。更多还原

【Abstract】 The mechanical behaviors of soils are dependent upon the structure and the stress state. Based on the unified strength theory, the unified strength parameters are proposed by introducing Lode’s angle into the unified strength theory. The critical state line is modified by considering the effect of the intermediate principle stress under the framework of the critical state concept. The effects of structure are introduced into the yield function of the modified Cam-clay model. The non-associated flow law is adopted. The equation for dilatancy stress is determined. A structural constitutive model that can reflect the effects of the intermediate principal stress is proposed. The model is verified by true triaxial tests of a clay. The results show that the proposed model can predict the stress-strain relationships well.更多还原