An expert fuzzy system for management of railroad bridges in use

Management of railroad bridges constitutes a typical decision-making problem which arises from the necessity to allocate limited financial resources to maintenance and repair work. It Is a multiple criteria issue consisting in the arrangement of bridges with regards to the level of structure degradation which is decisive for the safety level of their users. So far, despite a large number of suggested calculation models, mainly of probabilistic character, no method has been noticed that would allow to rank any number of bridges taking into consideration a full variety of structure and material solutions. Therefore, in order to meet the need for a more effective model, an innovative approach has been proposed using the aggregated calculation algorithm which combines the modified Extent Analysis Fuzzy Analytic Hierarchy Process (EA FAHP) method and the Dominant Analytic Hierarchy Process (DAHP) one. It is a decision-making and calculation model which allows to reflect the actual assessment processes in a more favourable manner, as well as to take into account the diversity of solutions with respect to materials and structure of bridges. An example was given of the application of the suggested method on the selected group of railroad bridges in Poland that have been in use for over 50 years. The selected structures have more diverse structures of decks and are more prone to damage than road bridges. Due to the lack of algorithms similar to the one discussed within this paper, it was verified In a limited scope with the use of two different methods by way of comparing the accordance of bridge ranking which is of importance for making a decision concerning the performance of maintenance and repair work.