The research of creep in tunnel which surrounding rock is expansion

Abstract

Abstract.Selecting the highway tunnel project in GuangXi province as the experimental research object,using Matlab numerical analysis software to analyze the creep data fitting,this essay concludes that the Generalized kelvin model is proper for creep model.Through converting the creep formula of generalized kelvin model with the third creep formula of implicit creep of ANSYS finite element software implicit creep,it determines the creep model parameters.On this basis,by performing numerical simulations in four different construction methods on expansive surrounding rock tunnel,fill-section excavation,CD excavation,bench cut method and double-side-drift method applied,it researches properties of time-varying mechanical.The results shows that the construction mechanics characteristics of expansive surrounding rock tunnel are effected by time.The deformation of surrounding rock is enhanced with the growth of time,but it tends to be stabilized on the fourth day.Excavation ways have an effect on expansive surrounding rock mechanics.The more one-off excavation rock area digs,the more changes in stress,strain and creep change for the expansive surrounding rock.Among the four kinds of excavation methods,double-side-drift method has best stress form and minimum creep variable.