中文摘要：

决定饱和岩土材料变形的有效应力σ′以及孔压系数B的表达式主要有2种不同的形式，为辨析其合理性，分析了不排水条件下，孔压增量和净围压增量作用下固相与骨架的体积压缩系数之间的关系，以及分别由孔压增量和净围压增量作用引起的液相、固相和骨架的体积增量，指出了σ′和B的两种形式的表达式在推求过程中各自存在的问题，并通过不排水和排水条件下的变形等效关系，建立了新的有效应力σ′和孔压系数B的表达式。

英文摘要：

In the literatures, there are two major forms of expressions of the effective stress σ′ and the pore pressure coefficient B controlling the deformation of saturated geomaterials. In order to discriminate and analyze their rationality, the relationship is investigated between the volumetric compressibility coefficients of the solid phase and the skeleton subjected to both hydrostatic pore pressure increment and net cell pressure increment under an undrained condition. Also investigated are the volumetric deformation increments of the liquid phase, the solid phase and the skeleton induced by the hydrostatic pore pressure increment and the net cell pressure increment. The problems existing in the derivation procedures of the two forms of expressions of σ′ and B are pointed out. Based on the equivalence relations of the deformations under undrained and drained conditions, new expressions for the effective stress σ′ and the pore pressure coefficient B are established.