Suspension Bridge Structural Health Monitoring Based On GPS Technology

In the 20th century, the achievement of the bridge engineering areas is reflected not only in prestressed technology development,the construction of large-span cable-supported bridge and the exploration on Super-span bridge, but also in people's ideas and efforts on the bridge structure to implement intelligent control and monitoring. Nearly 20 years, the research of bridges to wind and Seismic and the development of new materials and technology promote the development of large-span bridges; Meanwhile, With the large bridge safety, durability, and the use of the normal function growing concern, monitoring to a large bridge for structural safety, integrity, durability to ensure the normal operation of its security has attracted public attention. The research of health monitoring on bridge and the development of monitoring system came into being. Structure health monitoring of bridge is the monitoring of bridge structure state and assessment of the bridge in special climate, special traffic conditions or severely abnormal operating conditions , then triggering warning signals and analysis assessment of the bridge life, to certificate bridge design theory and to provide scientific basis to bridge conservation, maintenance and management decisions.Traditional structural health monitoring of bridge in monitoring systems, based on the traditional laid-based sensor components, such as : acceleration sensors, strain gage and temperature sensors. In recent years, With the development of global positioning system (GPS) receiver technology and software technologies, particularly, the improvement of GPS satellite signal solution accuracy, can achieve real-time, high-dynamic, high precision displacement measurement, static measurement accuracy can be achieved sub-millimeter, real-time dynamic measurement accuracy can be achieved sub-centimeter, the maximum sampling frequency of 20 Hz, can provide real-time monitoring to large structures for safety conditions.This paper first acted dynamic real-time monitoring on bridge of DalianBei with GPS, Then designed a nine-order Butterworth belt pass filter, filtering to the curve of the vibration of the structure at the way with Matlab Signal Processing Toolbox,, After this, acting spectral analysis by the FFT (Fast Fourier Transform), getting the natural frequency of the bridge structure, and comparing with Ansys finite element modal analysis numerical solutions , Finally the methods of GPS sensor and traditional acceleration sensor were compared.