Abstract: Aiming at the simulation problems on the inner anchoring section of prestressed anchor cable, composite element model is presented, which provides a new idea to solve this problem. The most remarkable feature of the model is that it not only can describe steel strand wire, mortar, interfaces and other detailed structures, but also simplify calculation mesh. Elaborate simulation is conducted in order to verify the new method. Steel strand wire, mortar, interfaces and other structures are discretized in detail. The results show that the axial displacement and stress are exponential decreasing along the steel strand wire from outside to inside. The longer inner anchoring section is not better for anchoring effect, but it is more suitable for 3-5 m. These are proved by field monitoring. Numerical example is carried out to display the validity and rationality of the method.

Key words: rock mechanics, inner anchoring section, composite element model