Study On Disaster Risk Of Corrosion And Strength Design Method Of Bridge Pier Considering Corrosion

As an important part of Chinese infrastructure construction,bridge is a transportation hub project bearing the lifeline of society and economy.It is related to the coordinated development of society and economy and plays an important role in the development of regional economic integration.The risk of corrosion hazards varies with the geographical distribution of chloride ions.In other words,the environmental chloride concentration greatly affects the safety,applicability and durability of structures in service,and the geographical recognition of corrosive environment is very important.However,the existing design codes and durability assessment guidelines for various types of structures lack the geographical statistical division of corrosive environment.Secondly,the existing structural design methods in China ignore the relationship between structural resistance and time.Due to the complexity of the mechanism of structural corrosion,the research on the reliability of structures in normal service stage is still in the exploratory stage,and the time-varying reliability analysis is even less.This paper focuses on the above issues,and the main contents are as follows:(1)Through literature research and open source data collection and other means to obtain environment of chloride ion concentration distribution,the test of goodness of fit and regression analysis method,studies the our country inland,coastal to the northwest Pacific Ocean,with latitude and longitude positioning environment statistics and geographic data sets,chloride ion concentration disaster risk analysis for structure design and structure reliability assessment and provides the basis.(2)Based on the information of chloride ion concentration in environment,the risk of corrosion hazard of a real bridge structure was analyzed,and the influence of chloride ion corrosion on offshore structure was explored.Moreover,the corrosion mechanism of reinforced concrete structures under chloride environment is considered and the influence factors of bridge pier corrosion degradation model is established,based on the time-varying model for calculating the ultimate bearing capacity of fiber grid method,the component piers corrosive environment based on the analysis of the durability of the reliability method,finally analyzed by an example the effects of design parameters on reliability of components.(3)Considering the resistance reduction of the components in corrosive environment,the concept of lifetime cost is introduced to determine the initial reliability index of the pier components.By adopting approximate probability design method and introducing durability coefficient on the basis of original design expression,a design method of corroded components based on life cost analysis is proposed.