Innovative Hybrid Structural Systems and Smart Monitoring for Sustainable Bridge Infrastructure

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The proposed research aims at developing innovative design and smart structural health monitoring for sustainable performance of bridge infrastructure. Focus is placed on two themes: Theme 1 - Development of Sustainable Hybrid Bridge Systems: Innovative corrosion-free hybrid systems are currently under development by the applicant. The main objective of this research is to develop an optimum design of a sustainable and more durable and cost-effective system for short- and medium-span bridges. The proposed system can apply to hundreds of bridges constructed every year. In the new system, the superstructure is built entirely from materials that are immune to corrosion. Advantages of the system include reduced self-weight and enhanced durability. The light weight reduces the required amount of prestressing and the load on the supports, resulting in a smaller size of the substructure, or allows for longer spans, which may lead to a smaller number of supporting piers in multi-span bridges and, hence, reduction in the initial cost. The enhanced durability reduces the maintenance cost and can lead to a bridge lifespan that is double or even triple that of the average traditionally constructed bridges. The long-term objective is to develop guidelines and procedures for the design, fabrication and construction of the new bridge system. Theme 2 - Development of Damage Identification Technique for Structural Health Monitoring: A vibration-based damage identification technique (DIT) is currently under development. It can detect structural damage, determine its location, and estimate its severity in in-service bridges. The DIT combines discrete wavelet transforms and spectral entropy in a relative procedure to detect and quantify damage-induced disturbances in bridge dynamic responses measured under ambient vibration. This relative wavelet entropy (RWE) based DIT is a practical means for damage identification in in-situ cases, where the bridge normal operation cannot be interrupted to perform dynamic excitation tests and when data from a reference (undamaged) state of the bridge are not available for comparison with data obtained from current (damaged) state. Preliminary results of implementing the RWE DIT in a variety of bridge components tested under static and fatigue loading have proved efficacy of the technique in identifying test-induced damage under varying operational and environmental conditions. The objective of this theme is to further develop the DIT to be able to characterize various types of damage and quantify their actual (not estimated) severity. This can be done by combining a finite element (FE) model updating procedure with the developed RWE-based technique. For this purpose, RWE indices obtained from bridge component tests will be compared with the ones obtained from the FE models. Different optimization tools will be investigated in this study to enhance accuracy of the FE models.