Analysis And Investigation The Upgrading And Modifying Project Of Jiangyin Bridge Structural Health Monitoring (SHM) System

The structural health monitoring (SHM) system has been applied to large-scale bridges in increasing numbers. By the aid of transducers settled on structure, the SHM system carries out long-term on-line monitoring for the working condition of bridge, assesses its basic status and structural behavior, and makes a rational plan of maintenance to avoid the occurrence of disastrous accidents. The key to SHM lies in technically the optimized layout of advanced transducers as well as the transmitting and processing of information with high efficiency, and theoretically the development of theory on structural damage identification and state evaluation. Whether a SHM system in bridge can work well in operation management depends on how to tackle these two problems perfectly in the design stage of SHM system and combine the system with structural safety evaluation rationally.Based on the upgrading and modifying project for the SHM system of the Jiangyin Bridge, this paper analyzes the original SHM system in many aspects such as system design and application of monitoring techniques etc, and investigates the principal key problems in the upgrading and modifying project.Firstly, after a succinct analysis of mechanical performance for the Jiangyin Bridge, the main problems existed in its original SHM system, were investigated in the aspects of monitoring concept, transducer arrangement and application of testing techniques. The design analysis was then made for the original SHM system of the Jiangyin Bridge in many ways such as item selection, transducer arrangement, network structure, data acquisition, monitoring mode, data storage, and design of application software etc.Secondly, on the basis of analytical investigation for the original SHM system, the constitution of upgraded system, layout of measuring points, application of monitoring techniques and design of subsystems were studied in combination with the upgrading and modifying project for the Jiangyin Bridge. According to the general constitution of SHM system for large-span bridges as well as structural characteristics of the Jiangyin Bridge, total requirements and considerations were proposed for the upgrading and modifying project, and the chief items to upgrade the SHM system were determined. Then, engineering designs were created for each subsystem based on transducer arrangement, requirement for data acquisition and technical parameter of transducer etc.Next, aimed at the total requirements and considerations of the upgrading and modifying project for the SHM system of the Jiangyin Bridge and combined with the reality of transducer arrangement and data acquisition, the system software and data treatment manner were investigated for the SHM system of the Jiangyin Bridge. For the system software, after the module division and functional design, the LabVIEW-based software interface and operation manner were suggested. The method of signal analysis and data treatment was presented for the upgrading and modifying of the SHM system, to meet the demands of the evaluation...