The shearing strength and tensile strength of soil body can almost ignored, but it exists certain structural integrity. After installing anchor bolt with certain length and density, anchor bolt and soil body can work together. It can cover the shortage of soil body’s strength and form composite soil. Anchor bolt has the main functions in composite soil.

1. Constraint force.

 

It depends on stiffness, strength and spacial combination form of anchor bolt in soil. Anchor bolt has the function of constraining the deformation of soil body and makes composite soil become a whole.

 

2. Bearing capacity.

 

In composite soil, anchor bolt and soil body bear external load and gravity stress together. After soil body reaching plastic state, stress transfers to anchor bolt gradually, anchor bolt’s bearing capacity is more prominent because of high shearing strength. The proportion of anchor bolt’s bearing capacity depends on stiffness ratio of anchor bolt and soil body, anchor bolt’s spatial location and composite soil’s stress level.

 

3. Transmission and diffusion of stress.

 

Under the same load condition, strain level in anchor bolt parts is lower than plain soil slope, which postpones the formation and development of cracking zones.

 

4. Constraint force of slope deformation.

 

Steel fabric sprayed concrete panel is settled on slope with anchor bolt, which restricts excavation unloading and swelling deformation and then strengthens constraint force to boundary.