Fuzzy-Based Method to Account for Subjectivity and Uncertainty in Bridge Condition Assessments

Bridges are important element of civil infrastructure systems as they support the society and the economy on daily basis. In many countries, existing bridge infrastructure is aging and deteriorating. Bridge management systems (BMSs) have been utilized to select appropriate maintenance, repair, and replacement (MR&R) actions to maintain existing bridges within acceptable safety and serviceability limits. Bridge inspection and bridge condition assessment are important steps needed to make bridge management decisions. The main limitation of bridge condition assessment through inspection is the uncertainty inherent in bridge inspectors’ subjective ratings while using linguistic expression to quantify defects associated with the various bridge elements. This can significantly affect reliability of the condition assessment process. This research reviews the fuzzy logic and the stochastic analysis utilized in bridge condition assessment to account for uncertainty and subjectivity and proposes a combined method to address both limitations in bridge condition assessment. Then, a systematic method for bridge deck condition assessment is proposed and demonstrated with a case study. The method benefits from both the fuzzy membership functions and the stochastic approach to account for uncertainty in bridge condition assessment. The method is simple and practical but it needs be validated further with more case studies to be accepted in practice.