Characteristics of stress-strain relation of remolded expansive soils in direct shear test

The direct shear tests of remolded expansive soils were performed for different dry densities and original water content with different stresses.The stress-strain relation and strength index of Nan(ning)-You(yiguan) remolded expansivesoils was studied.Results showed that with increasing dry densities,the peak strength of soil increases significantly,but the residual strength had no significant changes.The soil cohesion had an exponential relationship with dry densities,but soils angle of internal friction had little change with dry densities.With increasing original water content,shear displacement of peak strength increases,the cohesion and soils angle of internal friction first increases,then decreases.Increasing vertical pressure had some help to both the peak strength and residual strength of the remolded expansive soils.