Study On Key Technologies Of Health Monitoring System For Prestressed Concrete Cable-Stayed Bridge

In recent years,the bridge collapse accidents occur frequently,resulting in huge casualties and economic losses,so the establishment of bridge health monitoring system has a very important significance to understand and evaluate its health condition in real time.Taken a real bridge as background engineering,the key technologies of health monitoring system for prestressed concrete cable-stayed bridge are studied systematically,and the main content are as follows:Firstly,the description method of main bridge location is established and the existing condition of the example bridge is surveyed,including the linear measurement of the deck and the visual inspection of the main bridge.What's more,based on structural characteristics,operating environment and the maintenance and management,the requirement analysis of monitoring project for the example bridge is conducted,and the overall design of health monitoring system and sensor subsystem is completed.In addition,the finite element model of the example bridge is established,and further study is made on the analysis of vibration characteristics and parameters sensitivity.The results show that the focus monitoring project of prestressed concrete cable-stayed bridge is the cracks,strain and linear of box girder,tilt of bridge tower,force of cables,and environmental parameters.The cable-stayed bridge has a dense spectrum,the first two modes of vibration characteristics calculated theoretically or measured by dynamic load are the same,and the measured value is slightly larger than the theoretical value.The elastic modulus or shrinkage and creep of concrete are sensitive to deflection of main girder and cable force,while the beam weight is sensitive to deflection of main girder and is non-sensitive to cable force.