Research And Implementation Of Taizhou Bridge Wireless Vibration Measurement Monitoring System

With the development of transportation infrastructure in China, many complicated and diverse bridges and tunnels have been built. Therefore, the possibility of secure accidents caused by disaster or structure damage accumulation increases, correspondingly. To avoid these losses and tragedies, long-term or periodical structural health monitoring and safety assessment are quite necessary. Wireless sensor networks (WSNs), which incorporate technologies of sensing, communication and computation, collect information from deployment area through sensor nodes and their collaboration. WSNs, connecting information networks and physical world, have a promising future in various kinds of applications.The paper introduces the WSNs, components of WSNs nodes, basic network structure and ZigBee protocol in the first part, and then discusses principal theory and research status of Structural Health Monitoring (SHM). Full SHM systems are envisaged to:(ⅰ) verify design assumptions and models; (ⅱ) analyze responses and predict possible damages; (ⅲ) obtain experimental data for future research in bridge engineering.According to the three-tower suspension bridge scheme of Taizhou Bridge, a SHM system based on vibration measurement was designed. The system adopted heterogeneous network to take advantage of long-distance transmission and easy assembly of WSNs, avoiding disadvantage in high-noise or jammed environments in the same time. The architecture and base nodes, including acceleration sensor circuit and radio-frequency power amplifier, were designed and applied to Taizhou bridge SHM.In the end, we analyzed the girder, suspension cables and main cables of Taizhou bridge, and calculated the frequency and mode of vibration by establishing simplified models. Through comparison between actual vibration frequency from measurement and theoretical formula, the mode of vibration could be determined. Moreover, structure parameters calculated from measuring results were compared to design assumptions and parameters.In this way, we could detect anomalies in response, and ensure the safety of the monitoring structure.