In view of the pollution of unpaved road dust in the current mines, this study demonstrated the excellent dust suppression performance of the dust suppressant by testing the dynamic viscosity, penetration depth and mechanical properties of the dust suppressant, and apply molecular dynamics simulations to reveal the interactions between substances. The results showed that the maximum dust suppression rate was 97.75 % with a dust suppressant formulation of 0.1 wt% SPI + 0.03 wt% Paas + NaOH. The addition of NaOH disrupts the hydrogen bonds between SPI molecules, which allows the SPN to better penetrate the soil particles and form effective bonding networks. The SPI molecules rapidly absorb onto the surface of soil particles through electrostatic interactions and hydrogen bonds. The crosslinking between SPI molecules connects multiple soil particles, forming larger agglomerates. The polar side chain groups in the SPN interact with soil particles through dipole-dipole interactions, further stabilizing the agglomerates and resulting in an enhanced dust suppression effect. Soil samples treated with SPN exhibited higher compressive strength values. This is primarily attributed to the stable network structure formed by the SPN dust suppressant within the soil. Additionally, the SPI molecules and sodium polyacrylate (Paas) molecules in SPN contain multiple active groups, which interact under the influence of NaOH, restricting the rotation and movement of molecular chains. From a microscopic perspective, the SPN dust suppressant further strengthens the interactions between soil particles through mechanisms such as liquid bridge forces, which contribute to the superior dust suppression effect at the macroscopic level.

This study investigated contact distribution and force anisotropy associated with elliptical particles in granular soils within the pendular state of unsaturated soils, employing the discrete element method. The high cost of determining the micromechanical factors through laboratory tests justifies the use of this method. The macromechanical behavior of unsaturated granular soils depends on interparticle contact characteristics and liquid bridge behavior. The findings indicated that as the degree of saturation increased, both the shear strength and the anisotropy of the normal and shear forces initially rose before subsequently declining. Notably, the contact normal anisotropy exhibited minimal variation with changes in saturation. Furthermore, it was observed that as confining pressure increased at a specific eccentricity and degree of saturation, the associated anisotropies exhibited a continuous increase. In this context, as the eccentricity of the particles increased, the peak shear strength and its corresponding anisotropies initially increased and then decreased. Conversely, residual soil strength showed a consistent increase in shear strength and anisotropy with rising eccentricity.

Mineral change and micropore development are important deterioration features of soft rock during water-rock interaction, but ignoring the differences and contributions of potential physical and chemical processes in existing laboratory studies. This paper carried out multiple micro-measurements on mudstone and sandstone after powder immersion and wetting-drying cycles of coarse grains, and proposed a liquid bridge model to distinguish the potential microscale process. The results indicate a complementary relation of mineral composition in the sieved fine particles, increasing clay minerals, and decreasing detrital minerals and cement with wetting-drying cycles. The variation in mineral and ion is slight after 320 days immersion. Micropores develop along mudstone boundaries after the wetting-drying cycle, and fewer clay minerals are found in sandstone whose skeleton of detrital minerals remain undamaged. The repeating liquid bridge force, varied in direction and magnitude, softens the cement strength inter minerals and induces them detaching from rock skeleton and remaining micropores. Combining with the weak chemical action, the rock damage evolution driven by the liquid bridge force helps us clarify the specific microscale processes involved in a short period of water-rock interaction, on the mechanism responsible for desiccation cracks, water-soil erosion and rock slaking.