Dispersive soils, due to their high erodibility and cation exchange sensitivity, pose significant challenges in geotechnical applications. This study investigates the engineering behavior of such soils under a wide range of thermal regimes (25-900 degrees C), focusing on their mechanical, hydraulic, and physicochemical properties. Unlike previous studies that emphasized microstructure alone, this research integrates a broad range of analytical methodsmineralogical (XRD, SEM), chemical (CEC, SSA, carbonate content), and geotechnical (Atterberg limits, unconfined compressive strength, permeability, TGA) to capture a comprehensive understanding of thermal stabilization effects. Results reveal that thermal treatment significantly enhances soil performance: at 300 degrees C, dispersion decreased by 65% due to complete free water removal; at 500 degrees C, dehydroxylation induced structural rearrangement and mineral breakdown, improving both strength and permeability. At 700 degrees C and beyond, the formation of cementitious phases such as gehlenite and anorthite transforms the soil into a dense, non-dispersive medium, increasing UCS by 36.5 times and permeability by 12,000 times. These findings emphasize the effectiveness of high-temperature treatment as a sustainable and technically sound approach for stabilizing dispersive soils in geotechnical and environmental applications, including landfill liners, geothermal barriers, and contaminant containment zones.

Improvement of the mechanical properties of soil, such as density, compressibility and shear strength, is typically due to the variation in its inherent microstructure. This paper presents a microscopic study of the densification mechanism in granular soils subjected to impact loading. Both model test and discrete element simulation were carried out to quantitatively analyze the fabric evolution from a particle-scale perspective. Irregularly shaped particles were used in the simulation, on basis of which realistic packing structural information such as average contact number, contact area and branch vector length could be learned. The results reveal the microscopic densification mechanism that impact loading not only promotes the increase of contact number, but also enhances the contact area around per particle. Increasing of contact area has enriched the distribution of sutured contacts to form more steady mechanical status of soil.