Research On The Mechanical Behavior Of Shallow And Large-section Soil Tunnels

With the rapid development of economic construction,shallow and large-section soil tunnels are widely used in highway construction.Soil has its own unique mechanical properties as one especial rock.in view of poor researches on stress characteristics of soil highway tunnel.As the background to tianhengshan tunnel in Harbin,the paper studied the rock pressure and characters in force of soil tunnel.First,combination of Harbin Tianhengshan tunnel displacement meter measurement job, the use of MATLAB BP neural network toolbox and ANSYS10.0,structural analysis based on finite element method,the artificial neural network training samples of the relationship between the different mechanical parameters of surrounding rock and tunnel surrounding rock deformation is set up by positive direction analysis.combination of the construction process are measured from the tunnel measured displacement meter values,through the network simulation get the corresponding mechanical parameters of surrounding rock.Secondly,according to the actual situation of the tianhengshan tunnel,this article established the tunnel's two-dimensional plane strain model by using ANSYS,and analyzed that the soil parameters of DP model effected on characters of soil and lining structure.Third,the paper established three-dimensional finite element model in accordance with the results of inversion and calculated.through the results of the collation and analysis,the paper came to the law of the soil tunnel deformation with the tunnel excavation, obtained the scope of the tunnel excavation disturbance,stress release rate,Changes of principal stress,and analyzed the characters in force of supporting structure and the safety of the secondary lining,so as to providing the basis for design and construction optimization programs.In addition,the paper also studied the earth pressure of tianhengshan tunnel.through theoretical calculations and numerical calculation,come to the conclusion:for the tunnels like tianhengshan,as a result of very weak rock,hardly having basical self-support capabilities, we must adopt the entire soil column method calculation of rock pressure,which would be sufficient security.