Abstract: In this paper, isotropic compression tests on clayey soil with pore water of different salt concentrations were carried out. Meanwhile, the testing results were used to analyze the effect of osmotic suction on compressibility. According to the experimental results, isotropic deformation characteristics were significantly influenced by osmotic suction. As osmotic suction increases, the slope of initial elastic compression line increases and stress decreases, while the effect of osmotic suction on the slopes of elasto-plastic compression lines and swelling lines can be neglected. Based upon the experimental results, a constitutive model considering in-pore salty solution influence for clayey soil is proposed under isotropic condition. Through the verification, the model is valid for simulation of isotropic compression behavior. Additionally, the proposed model could be adopted to simulate the response of saturated soil with salty solution to the change in osmotic suction. The experimental result is of vital importance to develop a constitutive model considering chemical-mechanical coupling.

Key words: clay, NaCl solution, isotropic compressibility, constitutive model