Abstract：Starting from nonlinear characteristics of earth-rock aggregate，fractal geometry theory was used to study earth-rock aggregate strength properties .The stress-strain relationship，strength parameter characteristics and peak strength were analyzed under different confining pressures and fractal dimensions of granularity using large-scale triaxial tests. Relationships among strength parameters，peak stress difference and fractal dimensions of granularity were also discussed. Test results indicate that stress-strain properties of earth-rock aggregate were similar to stress-strain curves of typical rock，and strength envelope under different fractal dimensions of granularity was linear approximately. The earth-rock aggregate with 1D fractal had the largest compact ability and shear strength，which belonged to optimal gradation earth-rock aggregate and the reason was analyzed as well.
