In order to find the effect of total nitrogen on soil physico-mechanical performance

samples have been tested with deionized water and total nitrogen solution with different concentrations in laboratory

and the interaction mechanisms of soil and total nitrogen was revealed by mineral and microscopic analysis. The results show that the total nitrogen has significant influence on soil physico-mechanical performance. Plasticity indices

specific density and effective cohesive strength of samples decrease with increasing of concentration of total nitrogen solution

and the effective friction angle increases; Strain hardening phenomenon appears in the stress-strain relationships

and the variation of stress-strain curves of samples soaked in deionized water and total nitrogen solution are almost the same. The peak shear strength of samples manifests as a trend of decreases at first and then increases with increasing of concentration of total nitrogen solution; with the increase of axial strain

pore water pressure of sample is increased at first and then decreased gradually

and tends to be horizontal direction in the end; while the shear dilatation is evident; mineral composition

microstructure and physico-mechanical performance of soil are affected by the interaction between total nitrogen and soil

including ion exchange

microbial decomposition

dissolution and cementation.