SERVICE LIFE EVALUATION EXPERIENCE FOR EXISTING RAILWAY STEEL BRIDGE IN CHINA

It is well-known that the stress range spectrum is the key factor to the service life evaluation of existing railway steel bridge based on the damage accumulation theory. Taking two typical existing railway steel bridges in China as examples, two technical methods were introduced to determine the operation stress range spectra during the service condition in this paper, and then the service life was evaluated. One is named as Test Method and another is named as Load Simulation Method. Comparing the process and the, workload, pros and cons of two technical methods were studied. The actual load effects can be considered in Test Method, such as dynamic effect, acceleration effect, etc. But potential limitation of Test Method is too dependent on the test data, and the deviation of selecting the test position will affect the assessment result. Load Simulation Method can be used to calculate the fatigue stress history of any position, thus avoiding potential limitation of Test Method, but it must be based on adequate statistical information and large amount of calculation. In order to improve the accuracy of assessment results by these two methods in the future, some new research works are proposed at the end of the paper.