Force Analysis of Self Drilling Anchor
Self drilling anchor is one of important methods to sustain slope stability of rock and soil. Under ultimate load, self drilling anchor has grip force, frictional resistance between ground and anchor body, shearing strength of soil body, etc.
1. Self drilling anchor in soil layer.
Shearing strength of soil body is smaller than rock’s and than grip force between anchor body and self drilling anchor, so when confirming bearing capacity in soil layer, frictional resistance and shearing strength of soil body should be mainly considered. Standard compressive strength of mortar stone body should be not less than 20MPa.
2. Self drilling anchor in rock body.
Self drilling anchor will be destroyed in rock body because of lack of grip force between and , which demands standard compressive strength of cement mortar stone body should be not less than 30MPa.
After excavation, self drilling anchor supports in time and combines with surrounding rocks tightly, with good physical and mechanical properties. Through hollow thread bar, slurry can be invaded into cracks, seals joint, reinforces structural surface, enhances integrity and self bearing strength, restrains deformation development.