Prestressed anchor technics is a primary measure to reinforce rock masses in geotechnical engineering. It plays an important role in mobilizing the self-bearing capacity of the rock masses and improving the strength and self-stability of the rock masses. Because of the complexity and diversity of anchoring engineering

anchoring mechanism has not been well understood

and the design theory and related computational method are insufficient for engineering applications. Two important problems remain to be addressed

which are related to the existing analytical solutions of the stress transfer along the anchored section of the prestressed anchor cable. Firstly the stress variation along the anchored section of prestressed anchor cable has not been well characterized，and secondly the stress singularity at the endpoint has not been considered in the existing analytical solutions. Through the analysis of applicability and limitation of the previous analytical solutions

it is shown that the stress distribution along the anchored section can be divided into three stages: elastic stage

plastic stage and failure stage. The stress distributions are different in different stages. Within this context

an expression is developed for calculating the transferred load in the above three stages. The shear stress and axial force distributions along the anchored section are determined. For a practical case

the critical anchorage length is determined by the proposed equation

and the result is compared to those of other methods

showing the validity and capability of the proposed procedure