Experimental study of triaxial test of unsaturated soil of Yellow River levee

The characteristics of soil and water and shear strength of Yellow River dyke’s unsaturated soil under different confining pressures are studied by using special triaxial apparatus to simulate the real condition exposed on unsaturated soil in engineering. Based on the water-soil curves, it is easy to draw that the matric suction decreases with the increasing of surrounding pressure and water content; the effective friction angle changes little with the changing of water content; but the total cohesion changes greatly. The soil has bigger suction and total cohesion at lower water content. Based on the test results, the model of shear strength of unsaturated soil is presented with clear parameters. The fitting error is small and meets the calculation requirement of shear strength of unsaturated soil.