Effect of Total Nitrogen on the Physical and Mechanical Properties and Deformation Characteristics of Soil

Abstract

To determine the effect of total nitrogen on the physical and mechanical properties and deformation characteristics of soil, samples were tested in the laboratory after being soaked in deionized water and different concentrations of nitrogen solution. The results indicate that the total nitrogen content has a significant influence on soil characteristics. Specifically, the plasticity index, specific gravity and effective cohesive strength of the samples decrease and the effective friction angle increases with increases in the total nitrogen concentration of the solution. The strain hardening phenomenon is observed in the stress-strain relationship, and the variation of the stress-strain curve of samples soaked in deionized water and nitrogen solution are highly similar. The peak shear strength of the samples initially decreased and then increased with increases in the total nitrogen concentration of the solution. The mineral composition, particularly the composition of clay minerals, is affected by the interaction with total nitrogen in the soil, leading to changes in the soil macro-characteristics.