中文摘要：

综述了非饱和土有效应力的沿革，并就非饱和土有效应力的研究和发展中存在的问题进行了讨论。基于多相孔隙介质理论推导得到的变形功的表达式，提出了非饱和土广义有效应力原理。该原理认为，由非饱和土中的单应力变量的有效应力或双应力变量理论很难唯一地确定非饱和土的变形和强度。广义有效应力原理实质上就是要综合考虑影响非饱和土变形和强度的三种广义应力以及与其对偶的广义变形，给出考虑因素更为全面、理论基础更为坚实的广义有效应力原理。它为非饱和土基本性质的研究和本构方程的建立奠定了坚实而科学的理论基础。

英文摘要：

The principle of effective stress is the most important and fundamental principle in soil mechanics, by which soil mechanics has separated from continuum mechanics and become an independent discipline. Traditionally, however, the validity of the effective stress principle remains questionable for unsaturated soils. The historical evolution of the effective stress for unsaturated soils is reviewed firstly based on an expression of the work input into multiphase porous media; and then the formulation of the generalized effective stress for unsaturated soils is put forward. It is shown that neither the single effective stress nor the two-stress state variable approach is sufficient to describe the deformation and strength characteristics of unsaturated soils. By considering the deformation work input of unsaturated soils, the concept of generalized effective stresses that can be used to simulate the behavior of unsaturated soils is proposed. The proposed approach is fundamental and theoretically sound, paving a solid way to simulate the fundamental behavior and constitutive relation of unsaturated soils.