Abstract：Tunnel-type anchorage is not widely used in practice，and not enough attentions have been paid to its stability up to now. Based on the user-defined material subroutine interface provided by ABAQUS，a new model by combining Rankine and Mohr-Coulomb criteria is established，and corresponding interface program is developed，in which Fortran language is adopted. Based on this model，a three-dimensional elasto plastic finite element analysis on the tunnel-type anchorage of Siduhe suspension bridge is performed. The initial geostress field is calculated，and the construction process of the tunnel-type anchorage and road tunnel with New Austrian tunneling method is simulated. At the same time，the weak terrane around the tunnel-type anchorage appeared in the excavation is considered. The stability and safety factor of the rock around the tunnel-type anchorage are main contents. The results conform to those from FLAC3D analysis provided by Yangtze River Scientific Research Institute，which shows the feasibility and validity of the interface subroutine. The results can provide a reference to the current design rule of tunnel-type anchorage. Key words：tunneling engineering；finite element；UMAT subroutine；Rankine criterion；Mohr-Coulomb model；tunnel-type anchorage；elastoplastic analysis；stability
