The deep diversion tunnel for Yinda-Jihuang water transfer project is under high ground stress. Along the tunnel axis

the Ⅳ and Ⅴclass of surrounding rocks occupies a larger proportion. Under the action of high geostress

the surrounding rocks likely appear in large deformation instability to collapse after excavation unloading; these affected greatly TBM tunneling efficiency and construction schedule. According to the practical geological conditions and the surrounding rock revealed deformation characteristics

this paper adopts three-dimensional visco-elastoplastic numerical method to research aging deformation characteristics of the surrounding rocks. Based on the measured geostress field

and combining site deformation law of the surrounding rock

the creep mechanical parameters of rock is obtained by back analysis

then for weak rock visco-elastoplastic numerical analysis of excavation areas is caned out. Regularity conclusion is obtained

so as to provide the scientific basis for dynamic adjustment design