Research On Real-time Monitoring And Performance Assessing System Of Urban Existing Bridges

Bridge healthy monitoring system, based on bridge structure, adopting modern technology of sensor, telecommunication and network, is a synthetic monitoring system with the following functions of structure monitoring, environment monitoring, transportation monitoring, damage identification, comprehensive alarming, information analyzing and bridge maintenance. With the ability of real-time monitoring structural responses to environment and load, it can provide scientific foundation for bridge maintenance and management, ensure safety operation, and prolong service time. Besides, bridge health monitoring has significant influence on verification and improvement of structure design theory and methods, developing and realizing structure control technology and researching into unknown structural problem for large-scale bridges. In the recent years, for its important theory significance and practical value, the research health monitoring system is the concern for people from different fields such as bridge maintenance, designing consultancy and theory research.This paper expresses the significance to establish bridge health monitoring system, summarize the current situation at home and broad, existing problems and development orientation of the research in bridge health monitoring system. It discusses the crucial issues to be settled in relation to the structure and system of genuine bridge health monitoring system, including determination of monitoring items, selection and reasonable layout of sensors, and theories and commonly-used methods for damage detection and performance evaluation. Based on the R&D of real-time monitoring and performance assessing system of a bridge in Chengdu, this paper analyzes the characteristics in development of this system as well as the basic theories and crucial technologies thus involved. Emphases are put on basic principle of optical fiber sensor and its application in this system, the method for optimized layout of sensors, as well as methods for damage detection and performance assessment based on "limit value envelope method in design principle". Also this paper takes the R&D of real-time monitoring and performance assessing system of a bridge in Chengdu as an example, systematically explaining the design proposals for the network-based...