Study On Safety Analysis And Maintenance Countermeasures Of Expressway Tunnel’s Main Structure

With the rapid development of China’s expressway,the construction of expressway tunnel has made great progress.However,due to the influence of various factors,more and more tunnels appear lining disease in different degrees and bring potential security risks to the normal operation of expressway tunnel.Therefore,it is very important to study the tunnel lining disease.From regular inspection of several Zhang Zhuo expressways’ tunnel,it has been found that the main types of tunnel lining diseases include insufficient thickness of the lining structure,cavity behind lining,deformation of lining,water leaking,crack damage and corrosion of lining concrete.Through the theoretical analysis,it can be concluded that the factors causing the lining disease include topographic and geological conditions,construction quality,constructing methods and.maintenance management.Based on layer-structure method and using finite element analysis software MIDAS GTS,this paper build numerical models of the two major diseases,the insufficient lining thickness and cavity behind lining.According to the models,the influences on the structure safety are studied.The result shows that these two kinds of diseases,the thickness of lining and cavity behind lining,are main influencing factors to the safety of tunnel lining structure.With the development of the disease,the rigidity of the structural decrease,and the lining structure may be damaged correspondingly.Thus the normal operation of tunnel lining will be influenced.The tunnel lining disease exerts great influence on lining structure safety.Therefore maintenance management of tunnel should be given more attention.Based on the study of lining disease,scientific maintenance measures have been proposed.According to the preventive maintenance concept,we should set up the preventive tunnel maintenance management system and apply fuzzy comprehensive evaluation method to the health evaluation of lining structure in order to guarantee the safety of expressway tunnel operation.