IEEE ACCESS, cilt.1, sa.1, ss.1-13, 2024 (SCI-Expanded)
This study investigates the dynamic responses of the Davutpaşa Pedestrian Bridge to pedestrian
loads using low-cost and high-cost Global Navigation Satellite Systems (GNSS) along with accelerometers.
Traditionally, expensive dual-frequency GNSS receivers were employed for structural monitoring, but recent
advancements in low-cost GNSS technology have provided a cost-effective alternative. The study employs
signal filtering techniques and Fast Fourier Transform (FFT) to analyse datasets in time and frequency
domains. Specifically, the Yule-Walker Design of Infinite Impulse Response (IIR) Band-pass Filter is applied
to GNSS measurements to reveal natural frequencies obscured by noise. The accuracy was assessed by
comparing frequency values obtained through full-scale monitoring with those from a Finite Element (FE)
model. After filtering analysis, it has been determined that the natural frequencies obtained from geodetic
GNSS agree with accelerometer frequencies with a maximum difference of 0.12 Hz (3%). In low-cost GNSS
receivers, for the A10 antenna, a maximum difference of 0.09 Hz (3%), and for the UBX antenna, a maximum
difference of 0.10 Hz (3%) has been obtained, showing compatibility with the accelerometer. As a result, it
has been found that with appropriate filtering techniques and selecting sampling intervals suitable for
structural dynamics, even rigid structures like pedestrian bridges can have their natural frequencies
determined using geodetic equipment.