Vol19 No.11: 3286-3301
【Title】Stress analysis of full-length grouted bolt under shear deformation of anchor interface
【Author】ZHU Zheng-de1; SHU Xiao-yun1,2; LI Zhe4; TIAN Hong-ming2; TIAN Yun3*
【Addresses】1 College of Civil and Transportation Engineering, Hohai University, Nanjing 210024, China; 2 State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China; 3 School of Civil Engineering, Shaoxing University, Shaoxing 312000, China; 4.China Railway Design Corporation, Tianjin 300251, China
【Corresponding author】TIAN Yun
【Citation】Zhu ZD, Shu XY, Li Z, et al. (2022) Stress analysis of full-length grouted bolt under shear deformation of the anchor interface. Journal of Mountain Science 19(11). https://doi.orgk/10.1007/s11629-022-7566-4
【Abstract】The bolt anchoring force is closely related to the shear properties of the anchor interface. The shear stress distribution of full-length grouted bolts is analyzed based on the stress-strain relationship among the bolt, grout, rock mass and bond interface, considering the shear properties of the grout and contact interface bonding behavior. In this case, the interfacial shear stress of the grout and rock mass and the bolt axial force are obtained under pull-out and normal working conditions. The results show that the peak shear stress of the interface with the shear deformation of the bond interface is significantly lower than that without it when the pull-out force is applied. When designing bolt parameters of grade IV and V rock mass, the relative deformation between the rock mass and anchor should be considered, with a "unimodal" to "bimodal" shear stress distribution. In the case of a low elastic modulus of rock masses, both the shear stress concentration and distribution range are obvious, and the neutral point is near the bolt head. As the elastic modulus increases, the shear stress concentration and distribution range are reduced, and the neutral point moves towards the distal end. As a result, the optimum length of full-length grouted bolts can be determined by in-situ pull-out tests and decreases with the increased elastic modulus of the rock mass.
【Keywords】Full length grouted bolt; Neutral point; Interfacial shear stress; Bolt pull out condition; Normal working condition