Research On Structure Health Monitoring Method And Technology Of Long-span Steel Bridge

The national economic development can be influenced by the safety of long-span bridges, so how to protect the operational safety of long-span bridges that will become the key topics of bridge community in the next period of time. Through installing different kinds of senors in bridge structure, the bridge can become a intelligent bridge, that is one of the most direct and convenient way of protecting the operational safety. At home and aboard, many long-span bridges have been installed structure health monitoring systems. Due to complexity of bridge structure and testing environment, structure health monitoring of bridge is still in theoretical research and experimental stage. Specially, it is not mature that sensor optimization, analysis of mass monitoring data, structure damage detection and structural safety assessment, so the current technology have a more distant from the engineering objectives.In this paper, many bridge structure health monitoring systems are investigated and researched. Some key technologies and methods of the structure health monitoring system are systematically studied, as:sensor optimization methods, structure damage identification and structural health monitoring of bridges group integration platform. It is studied that sensor optimization, parameter identification and damage identification method by numerical calculation and model test. Structure health monitoring system platform of bridges group based on Web-GIS system are established; the new management model of monitoring systems are realized by establishing structural health monitoring of bridges group integration platform; this study is as follows:(1) The experimental verification platform that is used to verify key issues of the structure health monitoring system is established by making the test model. The test model of the long-span steel truss bridge is designed by similarity theory of thin-walled structure. Structure characteristic is verified by numerical calculation and model test.(2) Sensor optimization methods based on the effective independence algorithm is studied; and algorithm are improved according to structure dynamic characters. Relevant programs are prepared, and dynamics test sensor layout program of the monitoring system can be got.(3) These damage identification theories that include structure dynamic parameters analysis and structure response analysis are systematically explained in this paper. Many damage identification algorithms are comparatively studied.(4) It is studied that whether the structure has been damage, damage location and the influence of vehicles to bridge structural properties by numerical calculation and model test; and many damage identification methods based on modal parameter are studied. Structure properties that caused by changes of mass and stiffness are analyzed by wavelet packet signal analysis method; and wavelet packet on-line monitoring analysis methods are realized by numerical calculation and model test. Damage identification influencing factors that included noise, incomplete data and others are considered.(5) Structure health monitoring system platform of bridges group based on Web-GIS system are established in Jinagxi province as Jiujiang Yangtze River Bridge structural health monitoring system building. Functions of monitoring system software include data collection, data transmission, processing, real-time monitoring and structure condition assessment; and Jiujiang Yangtze River Bridge structural health monitoring system is integrated into bridges group monitoring software platform.(6) Data that include wind velocity, strain, deflection, acceleration signal and structure response data are analyzed by monitoring system; monitoring system can assess structural statement and be real-time warning. Some monitoring data of structural health monitoring system are verified by field testing; and both data correctness and system reliability are verified.