The shear strength and compressibility of soils are largely controlled by intergranular interactions. For clayey soils

however

the intergranular stresses remain elusive experimentally due to the complex physicochemical interactions between the clay minerals and pore water. To explore the effect of NaCl solution with different concentration on clay compression and to determine the intergranular stresses

a series of oedometer experiments was performed on the remolded samples prepared from a slurry mud. It is shown that at the same vertical stress

the deformation during osmotic consolidation increases with pore water concentration

and at the same concentration

the deformation during osmotic consolidation decreases as the vertical stress increases. Based on Terzaghi’s effective stress principle

the average intergranular stress is calculated based on the osmosis-induced deformation

and the dependence of intergranular stress (or the generalized osmotic pressure) variation on the pore water concentration and void ratio (i.e.

dry density) is determined. This paper provides a simple and yet effective approach to determine the intergranular stresses for clayey soils

which is helpful in calibrating the constitutive model of soils with multiple coupled physicochemical processes.