Use of the Factor Method and Survival Analysis in estimating the service life of the superstructure of bridges and road viaducts

Abstract Highway bridges are key elements for the economic and social development of any country, especially Brazil, which has the most used highway mode for transporting people and freight compared to the rail and waterway systems. This importance requires constant attention to the deterioration process to which such works are prone over time. It also requires the development of research on the assessment of performance, service life, and deterioration models, such as those being developed in several countries, to identify the conditions of stability and functionality, also contributing to decision-making focusing on planning necessary regular repairs and corrections. In this regard, this study intends to contribute to the evolution of this area of knowledge by presenting the results of the estimated service life of the superstructures of 98 bridges and viaducts of federal highways in the State of Pernambuco by applying the Factor Method and Survival Analysis techniques. The data of the set of works analyzed were obtained from the database of the National Department of Transportation Infrastructure (DNIT), in groups of the type of material of the superstructure (reinforced concrete and prestressed concrete), considering the information from the periodical inspections of such works in 2019. Among the results from the application of both methodologies, it is worth mentioning that the superstructures built using reinforced concrete have a higher level of deterioration than those using prestressed concrete. Lastly, the information obtained showed that both methodologies adopted in this study are reliable and consistent, since they produced appropriate results based on concepts validated in the literature for the intended purpose, and therefore can be used in estimating service life of the different typologies of Special Engineering Structures (SES) of Brazilian highways, even when there are limitations of information recorded in a database and the lack of regular inspection planning.