Bridges Risk Analysis in View of Repair and Maintenance by Multi Criteria Decision Making Method (Case Study: Babolsar Bridges)

Bridges built from any material and having any special shape will eventually show signs of wearing off; therefore, there are several factors in the kind and rate of such wearing off and its expansion such as atmosphere, flood, earthquake, overload, design quality, execution and kind of materials that will all reduce the functionality of the structures. Thus, maintaining processes and repairing the bridges may increase their life. In this article, after identifying effective risks on the bridges upon using them, critical risks are determined with FMEA method. After distinguishing the critical factors, each one is studied in details. Finally, three bridges in Bablosar (Iran), located over Babolrood River as well as their traffic role between the two sides of the city are investigated. Moreover, their roles on the traffic is also another case of interest in case with the destruction of any of these bridges, the communication to either side of the city faces serious problems. Also, the identified risks for each of these bridges are investigated to discern which of them is in no appropriate condition and if necessary they should be maintained and fortified. To do so, in this research by using AHP, ANP and Topsis Methods, these bridges are prioritized. Results show that the first bridge in this city has a worse state in comparison to the other ones and should be repaired, maintained, or fortified as soon as possible.