One of the parameters that plays an important role in assessment of existing bridges is the dynamic
amplification factor (DAF). Although many studies have already been performed in this field, it is still
unclear if DAFs, calculated from displacements, are larger than those, calculated from deflections and
which one of the two are more appropriate for assessment of existing bridges.
An existing simple highway road concrete slab bridge with double-sided overhang without dilatation,
that bridges a span of 10 meters, was analysed in this thesis. During measurements, 24 strain,
deflection and acceleration sensors were installed, the purpose of which was to determine the bridge
behaviour during several passages of a calibration vehicle. In order to simulate surface unevenness,
some of the passages included having a vehicle drive over a bump that was positioned in front of the
bridge or on the bridge.
Findings from selected previous studies that dealt with determination of the DAF are summarised and
the procedure, used for determining the dynamic amplification factor in this thesis is presented.
Typical signals from different sensors are shown, where the process of initial shift elimination and
signal smoothing is described. Maximum measured values together with their corresponding
calculated DAFs are presented depending on the speed of calibrated vehicle and sensor position.
Comparison between DAFs, calculated using strains and deflections, is performed with calculation of
the correlation coefficient r in order to identify at which speeds the most significant
relationship/connection of the calculated DAF from strains and displacement is observed.
Measurements from acceleration sensors were used to calculate deflections. Maximum values of the
calculated deflections were compared with the values, obtained from deflection sensors. In order to
find out at which speeds of calibrated vehicle the method used for deflection calculation is the most
accurate, the relationship strength between calculated and measured values was calculated for different
speed combinations of the calibration vehicle.
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