Field measurements at a composite bridge with composite dowels as shear connectors - Economical Bridge Solutions based on Innovative Composite Dowels and Integrated Abutments - page 77

Figure 23: Stresses in lower flange caused by crossing of test train (100 km/h, left) and
regional train (120 km/h, right)
Furthermore the crossing of the regional train (BR 132) with 120 km/h is compared to
a calculated quasi-static crossing. Therefore the estimated total weight of 58 t is distributed
evenly to all axes, which results in axle loads of 72.5 kN. Based on the cross sectional values,
the resulting moment distribution is transformed into theoretic stress curves for condition I
(orange line) and condition II (red line) (“Fig. 23”). These theoretic values show a good cor-
relation to the measured ones. The gliding mean value of both measured values (strain gauge
S45 and strain gauge S46) is situated between the curves of condition I and condition II,
which corresponds to the results discussed before. The small deviations in time between
measured values and hand calculation results can be attributed to dynamic effects.
It can be concluded, that there is a good correlation between calculated characteristic
stresses and measured stresses (section 4.1). Together with the evaluation of results in the re-
gion of the hot-spot, this leads to the conclusion that the given design concept and safe-sided
design rules based on stress concentration factors is applied correctly.
5. Outlook
The successful realization of the VFT Rail ® bridge in Simmerbach, combined with the prove
of the applicability of state of the art calculation methods by monitoring measures lead to an
extension of approval of this new bridge type in Germany [19]. In addition the general techni-
cal approval for composite dowels [3] was adopted in 2013, which allows for an economic,
timesaving and simpler application of these shear connectors in future.