Abstract: Due to the abundant negative charge existing on the surface of clayey soil particles, pore solution has significant influence on the physical and mechanical properties of clayey soils. The demanding geotechnical applications necessitates an effective numerical analysis of the detailed problems of chemo-mechanical coupling. Therefore, it is very important to develop a constitutive chemo-mechanical model on clayey soil saturated by salt solution. Based on the modified Cam clay model, a simple chemo-mechanical constitutive model is proposed. In the proposed model, the osmotic suction is adopted to describe the chemical state of pore solution in clayey soil. Formulas are presented to relate the pre-consolidated stress, the slope of critical state line M and elastic modulus to the osmotic suction. The comparison between simulated results and experimental data demonstrates that the proposed model is able to capture the isotropic compression, compression behavior for clayey soil saturated bysalt solution. The proposed model also can reproduce the response of clayey soil sample subjected to chemical and mechanical alternative loading. The simulated result for triaxial compression test also implies that the proposed model can capture the fundamental features of triaxial compression response of clayey soil.

Key words: clayey soil, salt solution, chemo-mechanical couple, constitutive model