To improve the substandard engineering properties of saline soil in cold regions and to mitigate the environmental pollution caused by conventional calcium-based stabilization materials, ionic soil stabilizer (ISS) along with lime and fly ash are added to saline soil. Triaxial tests and discrete element numerical simulations are employed to investigate the macro-microscopic mechanical properties of the ISS stabilized saline soil in a frozen state. The results demonstrate that adding ISS significantly improves the mechanical properties of lime and fly ash-stabilized saline soil under frozen conditions. The strength of the ISS stabilized soil reaches its peak at an ISS content of 3 %, but further increase in ISS content leads to a decrease in strength. The discrete element method (DEM) indicates that a failure surface forms an angle of approximately 55 degrees degrees to the horizontal plane, with particle displacement symmetrical about the failure surface. The pore structure is significantly influenced by confining pressure during loading, and a quantitative analysis is conducted on the changes in porosity and coordination number. This research offers valuable insights for improving the undesirable engineering properties of saline soil in seasonal frozen regions using ISS and for studying its macro-microscopic mechanical characteristics. Additionally, it contributes to reducing the use of inorganic materials, thereby promoting environmental protection.

In northern China, abundant summer rainfall and a higher water table can weaken the soil due to salt heave, collapsibility, and increased moisture absorption, thus the chlorine saline soil (silty clay) needs to be stabilized prior to use in road embankments. To optimize chlorine saline soil stabilizing programs, unconfined compressive strength tests were conducted on soil treated with five different stabilizers before and after soaking, followed by field compaction test and unconfined compressive strength test on a trial road embankment. In situ testing were performed with the stabilized soils in an expressway embankment, and the results demonstrated that the stabilized soil with lime and SH agent (an organic stabilizer composed of modified polyvinyl alcohol and water) is suitable for road embankments. The appropriate addition ratio of stabilized soil is 10% lime and 0.9% SH agent. SH agent wrapped soil particles, filled soil pores, and generated a silk-like web to improve the moisture stability, strength, and stress-strain performance of stabilized soil.