Abstract: In order to explore the residual strength characteristics of compacted loess blended with fly ash, and provide reference for engineering practice, we carry out experimental research on loess by using HJ-1 ring shear apparatus in the presence of different moisture contents and blending ratios of fly ash. The results showed that 1) with the increase of blending ratio of fly ash, the maximum dry density linearly decreases, whereas the optimum moisture content linearly increases; 2) if moisture content is below equilibrium moisture content, the relation between residual strength and blending ratio of fly ash shows tendency of negative correlation, otherwise, the relation shows tendency of positive correlation. In actual projects, we can treat wet soil with suitable proportions of fly ash to reduce the self weight of soil and to improve residual strength.

Key words: fly ash, loess, ring shear test, equilibrium moisture content, residual strength