Qualitative Fault Tree and Event Tree Model of Bridge Defect for Reinforced Concrete Highway Bridge

Due to a large number of bridges to monitor which contribute to the issue on the cost of inspection and maintenance that must be given priorities in the future maintenance process, it is important to have a comprehensive system in managing the bridge performance assessment by proposing the framework of structural integrity management system for reinforced concrete highway bridge in Malaysia. This new proposes system is using risk-based approach which may be emulated from SIMS of offshore platform structure. In general, the objectives of this study are to identify the bridge performance indicator in term of cause-consequence scenario in order to develop the framework of risk-based bridge management system and to create the risk matrix for prioritizing the inspection for maintenance. However, this paper only focuses on the evaluation part of the system which concentrates on the development of qualitative bridge defect model by using fault tree and event tree method. Fault tree method is used to identify the possible causes of bridge defect by considering the mechanism of bridge failure with referring to the failure mechanism classification from the existing practiced bridge management system and also based on literature review. While, event tree model is developed to determine what is the consequences of the bridge defect are and based on the developed event tree model, the consequences are divided into five condition of bridge failure known as disastrous, severe, medium, minor and good. Both models are significant for probability quantification and thus to determine the risk of bridge defect.