Triaxial Test Study of Deformation and Strength Behaviour of Sand-gravel Materials

The influence of densities on strength and stress-strain properties is studied by doing triaxial consolidation-drained shear tests on the different densities of sand-gravel materials.The results show that with the density increasing,the strength index of samples significantly increases;At different confining pressures,with the density increasing,the failure axial strain tends decreases;moreover,this trend is obvious under the condition of low confining pressure;the greater the density is,the stronger the dilatancy of test samples is,and the smaller the axial strains and volume deformation is;the stress level is greater than 0.5 at the state of phase change.It is suggested that the dilatancy of coarse-grained soil should be taken into account in the analysis of the stress and strain of high earth-rockfill dam.