A Study on the Failure of Resin End-Anchored Rockbolts Subjected to Tensile Load

Resin end-anchored rockbolts consist of three parts: (1) anchored section; (2) free section; and (3) faceplate and locking nut. Tensile failure of the bolt rod usually occurs in the free section. This paper presents a new model for end-anchored rockbolts loaded in tension by implementing a novel tensile failure criterion as part of a 3D continuum numerical modeling package. The proposed model is applied to the study of the behavior of end-anchored rockbolts in a deep coal roadway. The results are in close agreement with both experimental results and field observations in terms of load–displacement relationships and deformation characteristics. The results indicate that the use of rockbolts with high tensile strength and capable to undergo higher elongation would be a key controlling factor for designing excavations in deep coal mines, and the allowable elongation of the bolts in the ribs should be larger than the ones in the roof for deep coal roadways.