Stress Analysis of Full-Length Bond Bolt Considering Shear Deformation of Grouting Layer

Bolt anchoring force is closely related to the anchor shear properties of interface. Considering the shear properties of grouting and contact interface bonding behavior, the shear stress distribution of full-length bond bolt is analyzed based on the stress-strain relationship between bolt, grouting, surrounding rock and bond interface. In this case, both grouting-surrounding rock interface and the anchor axial force are obtained respectively under drawing. The results show that: The peak shear stress of the interface considering the shear deformation of grouting is significantly lower than that without consideration when the drawing force is applied. With the elastic modulus of surrounding rock increasing, the difference of peak shear stress is decreasing as well, and the value can be chosen as 30% under the hard rock condition. Under the soft rock condition, the peak interface shear stress is lower, with its distribution large, indicating that the long bolt should be chosen under the condition of soft rock. With the elastic modulus of surrounding rock increasing, the distribution of interface shear stress is decreasing, with peak shear stress moved towards to bolt head, indicating that the short bolt should be chosen and the interface shear strength should be improved under the condition of hard rock.