Abstract: According to the characteristics of elastic deformation during instantaneous loading and creep deformation tends to convergence changing with time which surrounding rock mass of Jinshandian's iron ore and powder ore have, reference to displacementtime curve obtained by field monitoring, chose PoytingThomson constitutive model, using finite element displacement analysis, integrated elasticmodulus   which include viscoelastic parameters was obtained, consider affect of excavation steps to surrounding rock mass deformation. Elastic modulus E1, E2, viscosity coefficient η had separated after made regression of integrated elasticmodulus, using these parameters into similar deformation prediction of powder ore tunnel, it could predict deformation amount and deformation stability time at different time of this surrounding rock mass.

Key words: Mining engineering, Surrounding rock mass deformation, Viscoelasticity, Finite element, Displacement back analysis