Stress Mechanism
- The soil nail is passively stressed, that is, after a certain deformation of the soil body, the soil nail is stressed, thereby preventing the soil from continuing to deform;
- The rock bolt is actively stressed, which means, by pre-stressing the anchor rod, the excessive deformation of soil structure is restricted before foundation pit is not excavated;
Field of Load
- The soil nail is full-length force, but direction of load force is divided into two parts. Potential slip surface divides soil nail into two parts. The direction of first half is directed to the direction of potential slip surface, and load direction of back part is directed back of potential slip surface.
- The rock bolt is free end of front half and forced section of rear half, so sometimes mortar is not filled in front half of rock bolt.
Working Mechanism Difference Between Soil Nail and Rock Bolt
The soil nail is a soil reinforcement technology, which uses the densely arranged reinforced body as the soil reinforcement means to improve the strength and self-stability of the soil to be reinforced;
The rock bolt is an anchoring technology, and the load of the unstable rock mass in the surface layer is transmitted to the deep stable position of the rock and soil body through the tension rod, thereby realizing the stability of the rock mass to be reinforced.
When soil structure is deformed, soil nail provides resistance with this deformation, and the force characteristics are the same as those of rock bolt. It’s just that it’s full length. The direction of the two broken forces divided by sliding surface is the same, both pointing into slope. Under action of prestressing, rock bolt is actively stressed, and always provides the resistance in the slope. With the loss of prestress and the stop of deformation of slope, it degenerates into a soil nail.