The viscoelastic B-K anchorage model can be computed efficiently. However

this rheological model is limited in application of mining engineering because it cannot well describe the mechanical characteristics of rock mass into plastic stage. In order to improve the Bolt-Kewin (B-K) model

a new viscoelasto-plastic anchorage model called BK-MC was proposed by introducing a modified Mohr-Coulomb (M-C) yield criterion. The increment iterative calculation scheme of BK-MC model was deduced in finite differential method first. Then

based on UDM interface program of FLAC3D

the corresponding calculation process was compiled by the VC++ programming language and called by DLL of Microsoft Visual Studio 2010. Finally

the BK-MC model was verified by the numerical simulation of uniaxial compressive test and applied to the stability analysis of deep roadway’s surrounding rock in Kouzidong mining area. The results show that the simulation displacement evolution process of roadway surface tends to be uniform with the regularity of field test data

which further verifies the validity and applicability of the BK-MC model. And it is necessary to consider mechanical properties of rock into plastic stage when studying the rheological problems of mining engineering.