Study On Remote Monitoring Information System Based On Optic Fiber Sensing For The Tension Of Bridge

With the rapid development of social economy, traffic volume and speed of automobiles also rise fleetly, which will be destructive to bridges in additional with unpredictable terrible weathers. Therefore, It is of great importance to design a reliable structural health monitoring system after construction finished. The long span concrete arch bridge has been promoted rapidly these years. Cable system is the main component, which support the gravitation of these kinds bridges. It has been an important part to bridge's health that monitoring stayed cable.In a long time, the health monitoring of bridges is by artificial means owing to the limitation of technology. Technicians take examination on bridge regularly and analyze data at laboratory with conclusion. By this means, we can not be acquainted with the status of bridges in time, and also waste human and material resources.The technology of optic fiber sensing has better advantages compared with traditional measurement technique, such as the more sensitive, corrosion resistance, insulation, explosion resistance and anti - interference, etc. It also has simple structure, small size, light weight and broad band, can be used in many kinds of distributed measurement for temper, stress and strain.Associated with the project, the research on monitoring automation and safety evaluation of bridge cable tension is investigated in this paper. The optic fiber sensors were used to measure temper and stress from cable, Internet was used to transfer data from bridge scene to control center and health monitoring and evaluation were executive in control center. This bridge health remote monitoring system consists of three parts: data acquisition, data transmission and data processing. The first part is a distributed system consists with optic fiber sensor, this part is designed to gather the state information of the bridge and send the data to computer as certain mode;The second part is designed to transfer the data to the clients in remote control center through Internet by TCP/IP protocols;The third part consists of database system and analysis system, it processes the data and gives a final conclusion.The main work of the paper is discussion of the work theory of Fiber Bragg Grating Strain Sensor, Fiber Bragg Grating Temper Sensor and FBG Load Cell, a design of distributed data processing system based on RS-485 Bus and remote Client application program by Visual Basic 6.0.At last SQL server 2000 was used to build the remote database system.