Displacement of Bridge Monitoring Techniques with Strain Measurement

General methods of displacement measurement are to use LVDT, tiltmeter, or laser deflection meter. But these methods can’t be applied effectively if bridge height is so high that the installation of sensor is difficult. So the great part of in these cases, the reliability and accuracy of measured results are uncertain usually. To overcome this problem, in this paper, the two techniques for calculation of displacement from measured strain are proposed, the one is iteration of data averaging, and the other is lowpass filtering of measured strain. To verify these techniques, laboratory and field tests are carried out, and it is concluded that lowpass filtering technique is effective for calculating displacement by measured strain. Keywords—Displacement, Bridge, Monitoring, lowpass filter, Strain.