For Ⅲ

Ⅳ grade rocks

the different deformation types of tunnel surrounding rocks are analyzed and forecasted using the elasto-viscoplastic finite element method based on Jiangxi highway tunnel. First

the Ⅲ

Ⅳ grade rocks are selected

to carry out indoor shear rheological tests and analyze generalized Kelvin rheological test curve and find the flow curves agree well with the model for Ⅲ

Ⅳ grades rock samples. Based on the generalized Kelvin model

viscoelastic model is derived under the stress - strain relationship of complex stress state. Finally

the dynamic viscoelastic back analysis method of the construction process is used to calculate rock parameters

combined with inversion parameters for prediction analysis of tunnel surrounding rock deformation. The research results are applied to the actual tunnel construction to guide and revise design and construction parameters

so as to provide a reasonable basis for safe construction.