Abstract:Research purposes : A large number of railroad reinforced concrete arch bridges in service stage are damaged by load,natural disaster,concrete ageing,and steel bar corrosion. The bearing capacity inadequate,ageing and damage problems caused by durability damage will directly threaten the safety performance of the structures and the carrying capacity. Taking a railway arch bridge as an engineering background,the durability is studied to assess the structural health based on the fuzzy hierarchy method and field test results. Research conclusions :( 1) Analytic hierarchy process can decompose the complex target problems into various factors, and these factors are grouped according to the control relationship. Fuzzy analytic hierarchy process is combined with the fuzzy evaluation method and analytic hierarchy process, and emphasizes the fuzziness and precise mathematical expression. (2) The hierarchy model of the railway arch bridge is established according to the field test results,the durability indexes of different components are given different weight coefficients. The comprehensive evaluation result for the railway arch bridge is grade I . ( 3 ) The evaluation results are consistent witli the field test results. So the assessment results by fuzzy analytic hierarchy process can refect the health of the important components. It has the characteristic of practicability, scientificity and objectivity. (4) The research results can be used to guide the bridge design and maintenance to prolong the service life of bridges.