Structure Damages Of The Concrete Girder Bridge And The Effect Analysis Of Structural Properties

With the rapid development of the national economy, the traffic volume and cargo turnover of the highways and urban roads increase violently, and the carrying tonnage of the vehicle and traffic density is also growing quite rapidly. Considering the phenomenon such as diseases and damages of highway and bridges, the use of performance degradation is very common. Currently, there are no uniform standards and methods to consider the impact of variety of damages and diseases on properties of components of the bridge with diseases. Practice is only to redact and to estimate roughly by experience according to the degree of damage, the accuracy of this way is not correctly. The information and literature about seismic response analysis of girder bridge with diseases is less. China is a quake-prone country., so the practical of the study on the anti-seismic property of bridge with diseases is more meaningful.In order to draw the affects of disease on the seismic response of the girder bridge structure accurately, the cause, mechanism of various typical diseases and the influence on carrying capacity and durability is studied firstly in this paper. The relationship between the diseases of the bridge and the decay of the structure performance is summarized. That the main diseases which affect the structure properties and carrying capacity of the reinforced concrete girder bridge are carbonation of concrete and steel corrosion caused by carbonation. The time-varying model of corroded reinforced concrete component has been established in this paper. With the increase of the amount of steel corrosion, its yield strength and ultimate strength decreased obviously, and the decline of the strength and plastic properties of corroded reinforced piers leads to the transformation of the structure failure from premonitory ductile to brittle. The nonlinear time history analysis of the rusting piers under seismic load is studied by OpenSees. There are results shown below:The effect of corroded steel on displacement response of the pier in seismic wave is a slight increase, but the effect on the internal force response is greater. The strength, ductile, deformation properties and energy dissipation capacity of the pier is reduced by the corroded steel, and then it drops seismic performance. The paper comes from Technology Fund of Yunnan Provincial Communications Department. The study is funding by the project-"The Study on the Status Quo and Countermeasures of Road and Bridge with disease in Yunnan Basing on Operational security risks".