Determining the critical status of bridges for allocating the repair and maintenance using hybrid fuzzy multi-criteria decision-making methods (Case study: Tehran urban overpass bridges)

The present paper aimed to develop a bridge management system using a combination of new fuzzy multi-criteria decision making methods. The developed system consists of a three-phase protocol. In the first phase, using past studies, personal intuitions and judgments and experts' experiences, a database containing critical factors affecting the critical condition of bridges was prepared, as well as identifying a number of urban overpass bridges in Tehran city with relatively similar characteristics and in need of maintenance. In the second and third phases, considering the uncertainties in the decision-making problem, by combining Delphi-SWARA-ARAS methods in a fuzzy environment, while screening and prioritizing more efficient and effective critical factors, the critical situation was assessed and the steps studied were selected. The results of Fuzzy SWARA method to determine the effective final factors showed that the factors of seam filling and discontinuity of the bridge related to the main structural index, average and duration of maximum annual rainfall at the bridge location of the main index of climate and hydrology, drainage, water discharge Surface and insulation of the bridge from the main index of safety, proximity and convenience of bridge access to adjacent arterial roads in terms of the main index of strategic (regional) importance, cost-benefit ratio for maintenance or reconstruction and replacement of the bridge from the main budget index and finally The volume of traffic passing over the bridge has gained higher ranks than the main index of traffic and pavement, respectively. Also, the results of Fuzzy ARAS method based on final critical factors (18 factors) showed that among the 24 bridges, Sheikh Fazlollah-SattarKhan, Hakim-Sheikh Baha'i, Hemmat-Africa, Lashkari-Aircraft industries bridges And Resalat-Haqqani with usefulness of 3.226, 3.171, 3.081, 3.080 and 3.077, respectively, are considered as the most preferred bridges in terms of the need for maintenance allocation.