Abstract: Roof bed separation often occurs due to the deformation incoordination of surrounding rock in the process of the excavation of mine roadway. Bed separation has effect on the bolts, and the estimation of the influence will directly affect the safety of support systems. The stress distributions of systematic bolt has been obtained, considering the pre-tightening force of end anchoring-grouting bolt and the additional stress caused by roof bed separation. The results have shown that under the influence of roof bed separation, anchorage axial force and shear stress will all increase．Anchor failure happens easily when bed separation value is too large, which will produce the potential safety hazard. Finally, the effects of bed separation have been taken into consideration in the bolting design, and a new bolt design concept has been provided. It has been proved that the bearing capacity design method after considering roof bed separation is safer and more reasonable．

Key words: roof bed separation, end anchoring-grouting, prestress, bolt loading, supporting design