Abstract: There is no a unified theory till now to compute the prestressed force of the cable. A new method for computing the prestress force is put forward by analyzing the existing methods for computing the cable prestressed force in design of anti-slide pile with prestressed cable. The cable, anti-slide pile, and the rock-soil surrounding the pile are regarded as a whole. Firstly, the total force can be got in the cable according the long-term load when the moments on the both side of the pile are equality; then to compute the prestressed force on the condition of compatible distortion. And comparing with others method in a landslide which crossed with a highway; the new method can make the force in the pile better. So the structure of pile-anchor can do better in protected system.

Key words: structure of pile-anchor, compatible distortion, long-term load, prestressed force of cable