The shear strength of the soil is lower than the tensile strength of the soil is almost negligible, but the soil has a certain structural integrity. After the soil nails with certain length and density are placed in the soil, the soil nails work together with the soil to make up the deficiency of the soil’s own strength to form the composite soil. Soil nails in the role of composite soil are:
- Hoop beam skeleton effect. This is determined by the stiffness of the soil nail itself, its strength, and its spatial distribution in the soil. It has the effect of restraining the deformation of the soil, and make the composite soil to form a whole.
- Share the role. In the composite soil, the soil nail and the soil shared the external load and soil self-weight stress, soil nails play a role in sharing. The proportion of soil nails is determined by the relative stiffness ratio of soil nail to soil, the spatial position of soil nail and the stress level of composite soil.
- Stress transfer and diffusion. Under the same load, the strain level of the soil nail wall is lower than that of the soil slope, thus delaying the formation and development of the cracking field.