On the surface, soil nails and anchor rods are similar, but they have different working mechanisms.

　　The anchor rod is divided into a free section and an anchor section along the entire lengthzhidao, In the retaining structure, the anchor rod acts as the fulcrum of the retaining members such as piles and walls, and transmits the lateral soil pressure acting on the piles and walls to the deep soil through the free section and the anchor section. Except for the anchoring section, the anchor rod receives the same tensile force over the length of the free section;

　　However, the tensile force of soil nails varies along its entire length. Generally, it is large in the middle and small at the two ends . The sprayed concrete surface layer in the soil nail support is not a main soil retaining component. Under the action of the soil's own weight, its The main function is to stabilize the local soil on the excavation surface and prevent it from falling apart and being eroded. Soil nail support is made of soil nails and the reinforced soil around itBack toThe body together serves as a retaining structure, similar to a gravity retaining wall .

　　In addition, anchor rods are generally pre-tensioned during installation to give active restraint to the soil; while soil nails are generally not pre-stressed, and soil nails can only be deformed when the soil is deformed.answerOnly then can it be passively stressed. The restraint of soil nails on the soil needs to be compensated for by the deformation of the soil. Therefore, it cannot be considered that the reinforcement of soil nails has a restraining mechanism.

　　Secondly, the number of anchor rods is usually limited, while the soil nails are densely arranged, and the construction accuracy and quality requirements are not as strict as anchor rods. Of course, there are also special cases in which the anchor rod is not prestressed and is grouted along the entire length and bonded to the soil. In a specific arrangement, it will be transferred to the soil nail.