Research And Practice On Arch Bridge On-line Monitoring System And Early Warning Index

Along with the national transportation infrastructure continue to improve, how to ensure the healthy operation of the project has become a priority part.. Recent years, along with the development of bridge damage evaluation theory, sensor technology, transmission technology and computer technology, many important bridges accomplished the implementation of the SHMS (Structural Health Monitoring System), that plays an important role in bridge maintenance.According to the different bridge health monitoring,the contents of SHMS is different. Generally speaking, SHMS includes system layout optimization, sensor data acquisition and transmission system, data processing system and the early warning evaluation. This paper focuses on the research of the sensor layout method, data transmission, temperature correction, BP neural network, damage identification and established safety warning index in practical engineering. The main research contents are as follows:(1) Based on the bearing of open spandrel arch bridge force characteristics of the risk analysis, the low reliability, stress larger dangerous, section position as the sensor optimization acquaintance of arrangement of measuring points selection. Then, based on the error propagation criterion and the bending strain energy method respectively on T beam and main arch ring test point selection are calculated and analyzed.(2) on the basis of the test principle of the sensor, focuses on the study of the thermal effect coefficient sensor mounting member in the whole structure of the value in not fully get real-time temperature field under the conditions of different components, the interaction between the component and the component difference leads to determine the size of the beta value, provides the calculation method of temperature effect of matrix and for the realization of computer software.(3) to move the load time history analysis data as the training sample of neural network, BP neural network to study the bridge damage identification system.(4) according to the level of technology state of the bridge to determine its ultimate bearing capacity, combining with the traffic live set orange or red security early warning index system in correcting system.