TITLE:
Rigid Bridges Health Dynamic Monitoring Using 100 Hz GPS Single-Frequency and Accelerometers
AUTHORS:
João Olympio de Araújo Neto, Jorge Luiz Alves Trabanco, Ana Paula C. Larocca, Andre Luiz Cunha, Marcelo Carvalho dos Santos
KEYWORDS:
GPS, Rigid Bridge, Modal Frequency, Wavelet, Accelerometer, Health Monitoring
JOURNAL NAME:
Positioning,
Vol.10 No.2,
May
31,
2019
ABSTRACT: This
article presents the modal frequency recordings of a rigid bridge, monitored by
the GPS receivers (Global Positioning System) with a data recording rate of 100
Hz and accelerometers. The GPS data processing was performed through the double-difference phase,
using the adjusted interferometry technique (i.e. phase residue method—PRM®). In the method, the double-difference phase
of the carrier L1 is realized by using
two satellites only, one was positioned at the zenith of the structure and the
other satellite was positioned near the horizon. The results of the parametric
adjustment of the PRM observations were finalized through software
Interferometry, mathematical algorithm were applied and compared with the accelerometer. The comparison served to
validate the use of GPS as a fast and reliable instrument for the preliminary
monitoring of the dynamic behavior of the bridge, road artworks which are
common in several countries, especially in the Brazilian road network. The data time series from the GPS and
accelerometers were processed using the Wavelet. The detection of frequencies
means that the combination of 100 Hz GPS receivers and the PRM allows detecting
vibrations up to 5 mm. It presented significant results which were never obtained
by the Fourier Transform.