Design And Damage Analysis Of Health Monitoring Oriented Experimental Cable-stayed Bridge Model

Cable-stayed bridge is more and more extensively applied in highway and municipal road currently, however the problems of various types of damages such as cable corrosion/breaking, main girder damage or foundation displacement have been increasingly emerging for these years, which cause the bridge injured or even collapsed, eventually affecting the normal services of the structure. Studying on the influence law of the static responses of the cable-stayed bridge due to these damages and then providing reasonable guidance for sensor placement, so as to detect these damages timely and accurately, is of great theoretical value and engineering guiding significance.The study puts forward the general idea of designing a small-scaled cable-stayed bridge on the background of a three-span prestressed concrete cable-stayed bridge in Hangzhou. Fully according to similarity relation, a small-scaled cable-stayed bridge is virtually built, and comparisons are made among the model and prototype numerical analysis and prototype field static and dynamic test results. The results show that for cable-stayed bridge which is one kind of combined system structure, stiffness similarity method is suitable when there are two different elastic modulus similarity ratios. Then according to the purpose of model test, the ideal model is appropriately simplified, and a health monitoring oriented model bridge which can represent a cable-stayed bridge in practical engineering is designed. Lastly, some critical construction details are presented for manufacturing problems in future.Based on the cable-stayed bridge model, the influence law of the static responses of the cable-stayed bridge is studied in the cases of cable damages at different location/severity, main girder damages at different locations and foundation displacement, respectively, and damage sensitive locations for these responses are obtained.Based on the sensitivity analysis above, monitoring strategies for cable damage and foundation displacement are proposed, and monitoring model for foundation displacement is established. Finally, a layout scheme of sensory systems for damage monitoring is built for the cable-stayed bridge model based on sensitivity analysis, providing theoretical guidance for damage monitoring for similar cable-stayed bridge structures.