The Effect Research Of Durability And Mechanical Properties As Lining Structure Of Fang Dou Shan Tunnel By Sulfate Corroded

Today,many underground engineering such as subway and tunnel are being constructed rapidly.However,the environment in which underground engineering are complex.Therefore,it is of great significance to the development of underground engineering,that the durability of underground engineering is improved.This is the study of Fang Dou Shan Tunnel.Aiming at the durability problem of the Fang Dou Shan Tunnel such as Lining corrosion,Lining cracking and seepage,Pavement deformation and Lower lining strength reduction,this paper studies the effect of sulfate on the durability of lining structures and predicts the Life of anticorrosive concrete in the Fang Dou Shan Tunnel renovation project.Finally,this paper analysis that deformation and stress variation of tunnel structure as the strength of invert arch become lowering and its effect on durability.Firstly,according to the present situation of the tunnel disease in the Fang Dou Shan Tunnel,this paper evaluate the durability evaluation of the renovating section of Fang Dou Shan Tunnel and analysis of the reasons for reducing the durability of the tunnel structure.The various of corrosion mechanism is combined with the disease of Fang Dou Shan Tunnel.then this paper ascertain the type of sulfate corrosion in Fang Dou Shan Tunnel.Secondly,this paper research that Influence factors of resistance sulfate corrosion of concrete and confirm the sensitivity factors by correlation analysis.In view of the influencing factors,this paper put forward the quality control requirement and measures in site.this paper demonstrate corrosion resistant concrete has better resistance to corrosion sulphate by 120 dry and wet cycles in 5% sodium sulfate solution.Thirdly,this paper make a Life prediction of anticorrosive concrete for renovation project?First of all,this paper adopte the theory of the decay equation of concrete by proposed Liu Chongxi,considering of the influence coefficient of various factors.then this paper make a prediction of life of anticorrosive concrete in Fang Dou Shan Tunnel.Aiming at the phenomenon that the content of sulfate ion is high in parts,this paper have a life prediction of corrosion-resistant concrete at higher sodium sulfate concentration.this life prediction that predict service life in 5% sodium sulfate solution is based on the grey theory.Fourthly,because of corrosion of sulfate to inverted arch concrete,the deformation andstress of tunnel vault and invert arch are analyzed by simulating the strength reduction of invert arch by Midas.then,this paper analysis its effect on the durability of tunnel structure.And then aimed at the anticorrosion concrete of the renovation project,this paper analysis deformation and force of tunnel structure when the strength of anticorrosive concrete reaches 75%.In this way,the improvement of durability is analyzed as renovation project.