The shear tests of bolted jointed rock mass were carried out in the laboratory to study the mechanical behaviors of anchor bolt in the jointed rock mass. In the experiment

rock mass of different strength

anchorage mode and prestress were simulated

meanwhile

the deformation characteristics of anchor bolts were monitored to compare the shear deformation regularity before and after bolting and to analyse the influences of prestress

rock strength

anchorage mode on shear capacity of jointed rock mass. Change of axial force was monitored through the strain gauge to study the axial deformation mechanism and force characteristics of anchor bolts. The distorted anchor bolts were taken out to analyse the relationship between the deformation length and other parameters after shearing test. Several conclusions were derived from the results of above tests: Shear stress vs. displacement curves can be divided into three stages: elastic stage

yield stage and plastic hardening stage

and show a feature of approximate double-linear lines. In elastic stage

the bolts act as “pin”. In yield stage

the axial effect was activated and bolts functioned as both pin and confinement effect. In plastic stage

the bolts did not take the effect of pin

and just restricted the deformation of rock though its axial confinement effect. Shear load vs. displacement curves presented as plastic hardening mode

which means that the toughness of bolted jointed rock mass will be enhanced; and the failure mode changes from fracture mode into yield mode. So that the stability and safety of bolted jointed rock mass were improved. The bolt was sheared as a result of slippage of the joint and was led to additional axial deformation due to lateral deformation

the axial stress increased with the shear displacement. The region of distortion of the bolt concentrated nearby the joint surface and the closer to the joint surface

the more the augment of the axial stress was.