A shear strength model for unsaturated clay considering the influence of salt solution under a wide saturation range
WANG Liye1, NIU Yubo1, LI Hongbo1, MA Qiang2, ZHOU Fengxi3*
(1. School of Civil and Hydraulic Engineering, Ningxia University, Yinchuan, Ningxia 750021, China; 2. School of Civil Engineering and Water Resources, Qinghai University, Xining, Qinghai 810016, China; 3. School of Civil and Hydraulic Engineering,
Lanzhou University of Technology, Lanzhou, Gansu 730050, China)
Abstract：The interaction between clay mineral particles and pore salt solutions significantly influences intergranular capillarity and adsorption effects, thereby altering the shear strength of unsaturated clay and impacting the stability of infrastructure in saline soil regions. To elucidate the influence of salt solutions on the physicochemical interactions of unsaturated clay, total saturation is categorized into capillary water saturation and adsorbed water saturation, based on generalized soil skeleton theory. Subsequently, an effective stress equation and a soil-water characteristic curve (SWCC) model that incorporate osmotic suction are proposed. The effective stress equation is derived by examining the relationship between the virtual work responsible for volume changes in the generalized three-phase system and energy changes in the capillary water state, which primarily comprises net stress, capillary stress, and osmotic stress. The SWCC model integrates the impact of osmotic suction on adsorbed water content, as well as the linear relationship between the air entry value and osmotic pressure, effectively characterizing the water-holding properties of unsaturated saline clay. Building on this foundation, a shear strength model for unsaturated saline clay is proposed, and its predictive capability is validated using experimental results from unsaturated clay subjected to varying saline conditions. The findings demonstrate that the proposed shear strength formula not only accurately captures variations in the shear strength of unsaturated saline clay under different matric suction and osmotic suction conditions but also reflects the physical and mechanical mechanisms by which salt solutions affect shear strength.
王立业1，牛宇博1，李宏波1，马 强2，周凤玺3*. 宽饱和度范围下考虑盐溶液影响的非饱和黏土抗剪强度模型研究[J]. 岩石力学与工程学报, 2026, 45(5): 1571-1583.
WANG Liye1, NIU Yubo1, LI Hongbo1, MA Qiang2, ZHOU Fengxi3*. A shear strength model for unsaturated clay considering the influence of salt solution under a wide saturation range. , 2026, 45(5): 1571-1583.
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2026, Vol. 45 
