Methods Study Of Damage Identification And Condition Evaluation On Long Span Cable-stayed Bridge Structure

Along with the development of economic and technology in our country, so many large and original forms of bridges are coming forth.The numbers of bridges are more.The safety of bridges relate with the safety of live and property belong to people,the stabilization of the society, the continuable development of economy. The bridge health monitoring therefore become so important, and moreover, based on the expeditiousness identification of damage position and level, the mastery of the bridge health operation condition become more important.Refer to the theory and methods about the bridge health monitoring and the Fengjie Yangtze River Bridge, it established a precise three-dimensional finite element model of the bridge by finite element softs, analysed the internal force of long span cable-stayed bridge, optimized the force of cable, and confirmed the reasonable bridge station, and modified the model by the measured data at first. Then, Based on the concept of modal curvature and flexibility matrix,two damage locating indices are used to identify various damage cases simulated in the main girder. The conclusions indicated that the two indices can detect definitely the position and level of damage and it also has a better ability to resist the noise.Finally, based on many effective monitering methods , it set down the bridge health monitoring project, and researched the condition evaluation ground on the theory of AHP and the measured data. At the same time, it evaluated the condition of the Fengjie Yangtze River Bridge.The study work of this paper is to provide a set of economical, practical and effective project for the establishment of the Health Monitoring System of the Fengjie Yangtze River Bridge, and provided an example for the development and application of the Bridge Health Monitoring System.