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Indexed by:会议论文

Date of Publication:2009-07-22

Included Journals:EI、Scopus

Abstract:Nowadays, there are more large scale structures such as long span bridge, dams and high rise buildings than in the past. These structures are being designed to be much more flexible and to resist extensive damage from changes in temperature, severe wind gusts and earthquakes. Dynamic characterization of civil engineering structures is becoming increasingly important for dynamic response prediction, finite element modal updating and structural health monitoring. For many years, monitoring the dynamic behavior of engineering structures has relied on measurements made by accelerometer, which requires a double integration process to arrive at displacements. This process is not readily automated because it requires selection of filters and baseline correction. The Global Positioning System (GPS) as an alternative method has been tentatively used in the health monitoring of large structures such as long-span bridges, high-rise buildings and high industrial chimneys in recent years since it is weather independent, capable of autonomous operation, and does not require a line-of-sight between target points. The aim of this paper is to show the real-time kinematic (RTK) GPS to measure the low-frequency vibration of a medium span suspension bridge. The field data, such as acceleration and displacement responses were simultaneously and continuously measured under ambient excitation. The spectral densities of the displacements measured by GPS corresponded with the numerical results by the finite-element method analysis and the forced vibration test results. The mode frequencies of both results showed good agreement in the low frequency range and the spectral peaks estimated by the accelerometers corresponded to the GPS values with good accuracy. It is concluded that the GPS method is reliable and useful to clarify the ambient vibration response behaviors of flexible structures.