Research And Application On Structural Health Monitoring Of Long-span Bridge

In the past century great breakthroughs have been achieved in bridge construction, and the construction is developing toward large-scale, lightweight and complexity in fuction. As bridge structures play an important role in national construction and nomal life of people, the safety and durability has been attached great importance. Engineers and technicians are concern about not only design and construction technology, but also maintenance and security. With the development of science and technology, health monitoring, safety assessment and lifetime prediction in morden bridge structure has become one focus in bridge engineering.This research was supported by the Science and Technology Development Projects of the Ministry of Railways: Applied research of measurement technology by optical fiber in Liaohe River Bridge of Qinshen Passenger Line(2001 G018-B), Research of Long-time monitoring, safety evaluation and alarm system of Wuhu Changjiang River Bridge(2000G19-B). in this paper, focused on development and application research of optical fiber signal transmission technology and bridge monitoring system, by using the method of theory combined with practice, a series of key technology problems has been researched deeply. The main research work include:1. Structural design project of bridge monitoring system has been proposed, the key technology in lage-scale bridge structure monitoring has been analyzed systematically, a series of technology and method include monitoring system design, confirmation of monitoring content,display and optimization of sensor, data capture and analysis, structural health evaluation have been proposed, foundation have been laid for the development of bridge monitoring system.2. white-light interference strain optical fibre sensor and temperature optical fibre sensor applicable to concrete structure have been developed successfully. By using morden measurement technology and the method of theory combined with practice, the relevant problems of technical properties, structural theory design method, manufacturing process, performance test have been analyzed systematically, an effective way for the national research and development of optical fibre sensor has been porposed.3. According to the complex construction technology and serious environment, the effective technology and method have been proposed to measure static and dynamic parameters of strain and temperature by optical fibre sensor. The key technology of optical fibre sensor in measurement of large-scale conrete structure have been analyzed systematically, and optical fibre sensor have been applied successfully in temperature measurement, prestress display monitoring, dynamic measurement, foundation have been laid for the wide use of optical fibre sensor in construction and long time monitoring in concrete bridge.4. Long time monitoring system for Wuhu Changjiang River Bridge(continuous beam part) has been designed. Based on the design project of health monitoring system metioned above, concerned about structural character of Wuhu Changjiang River, a set of technical system based on two-grade LAN multi-sensors data capture has been proposed, the relevant software for net data capture of long time bridge monitoring has been developed, alarm and forecasting system for bridge security has been realized.