A new analytical model for split-set rock bolt under pull-out force has been developed. Research shows that slips may occur first at the loading point under pull-out force when the applied load is large enough. The length of slip segment increases with an increase in the applied load

and finally the length of slip zone arrives at the length of rock bolt. Based on the conservation of energy

formulae of radial forces acting on the surrounding rock mass induced by split-set rock bolt are obtained. On the basis of nonlocal friction model

the distribution of shear stress on the interface of split-set rock bolt is determined. Through the parametric study of an illustrative case

effects of the rock bolt’s diameter on the distribution of shear stress is studied

the relationship between the ultimate pull-out strength and rock bolt’s length is also obtained. It is shown that the present analytical model is in good agreement with the experiment results.