Reliability Evaluation Of Existing Railway Bridge Structures

With the rapid development of our country's economy, transportation plays more and more important role. Bridge is an essential component of the transportation, so its management and maintenance is of great importance to retain the normal operation of transportation system. The bridge evaluation is closely link with the bridge management and considered as the foundation of maintenance. In this dissertation, the reliability analysis of existing railway bridge is mainly discussed.Railway bridge is affected by many factors such as the internal and external ones in its function,which causes different degree of damage and results in the change of structure function. So the reliability of bridge varies with time. The railway bridge is a complex structure system, whose reliability is affected by many factors and these factors may relate with each other. Therefore, it is a great challenge to evaluate the reliability of bridge. Analytic Hierarchy Process (AHP) method is often practically used in assessment. AHP can coordinate and classify various factors to determine the analytical hierarchy and the bridge's reliability. It is applied in the paper to analyze the structural system of bridge, acquire the assessment indexes of railway bridge and build the comprehensive evaluation model of RC railway bridge. Fuzzy Theory and Statistical method are also induced to the evaluation system of bridge to synthetically assess the factors in grades. New consistency modification of judgment matrix is employed to modify the experts'judgment matrix, to determine the weight vector of factors and the final reliability grade of bridge. A program which supports visual interface is designed for the assessment. It is simple, clear and easy to use.Based on the above research on the reliability of bridge, an evaluation method is derived to assess the reliability of the existing railway bridge and can be referred by railway bridge evaluation.