Shallow Tunnel Construction Monitoring And Stability Analysis

Along with the specialty of Shanling highway tunnel construction in HeBei province,Weanalysis the character of geological disasters of the valley period of shallow buried tunnels,andstudy the support structure deformation characteristics that tunnel across the valleys in theprocess of the weak intercalation in the way of flac3Dnumerical simulation.The plan of thetunnel support design is optimized, the process of tunnel construction is monitored andmeasured.We get the conclusion according to the numerical simulation analysis and themonitoring measurement.1)Gravity stress field in the internal of rock mass is influenced by the ups and downs ofterrain.And it is also influenced by the stress concentration when the geological section under thevalleys is weak.The degree influenced is the most in the interface of contacting.So,we design itnot only by the <specification of highway tunnel design>,but also increase the safety factor.2)The contact surface between the weak geological section and the good geological sectionis the most dangerous,and the tunnel easily collapse.The measures of advancing bearing and themodification of construction parameters should be considered.At the same time, to prevent thedisasters, the necessary advance geological forecast should also be done.3)The monitor of tunnel mode concrete strain the monitor of steel grille reinforcementstress and the monitor of the amount of deformation of tunnel surrounding rock convergence aredone to valleys shallow buried tunnel segment.The conclusion show that after improving tunnelsupporting structure and construction measures,the stability constant can be insured by themeasures of tunnel surrounding rock supporting.