Of Environmental Factors On The Railway Bridge Pile Foundation Corrosion Fatigue Research

Currently the study of reinforced concrete bridges shows that the carbonation of concrete, the long-term corrosion of bar and the fatigue damage of the bar because of cyclic reverse loading are the main reasons that affected the life of the reinforced concrete pile foundation in railway bridges .In this paper, the environment erosion and the fatigue damage are contraposed, the corrosion fatigue damages of the pile foundation in railway bridges under the disadvantageous factors are studied and explored. From the causes of Concrete carbonation and the mechanism of bar corrosion, Based on the existing experimental results of electrochemical principles, the time-varying model about bar corrosion of pile foundation is established. Diffeented from the theory of fatigue damages that considering only fatigue loads, the fatigue of pile foundation in railway has its own characteristics under the influence of environmental factors, both corroded material and mechanical fatigue need to be considered, namely, corrosion fatigue analysis have be done; The characteristics of fatigue corrosion of the pile foundation in railway bridges are studied in this paper, from the aspect of the damage area of the reinforcement, the theoretical calculation of components after corrosion are compared and choosed, the prediction model of the concrete pile foundation in various stages of corrosion fatigue is established with linearity of segment, being applied to corrosion fatigue forecasts of different long-span bridges rust pile foundation.At the same time, the program is writed to calculate the fatigue damage and residual life of some pile foundation in railway bridges, the results show that the damage size caused by environmental degradation determines the fatigue life of the pile foundation, in this paper, some meaningful preservation and strengthening measures are brought forward.