Traffic load model for road bridges in the urban road network
L.C. la Gasse1, R.D.J.M. Steenbergen1, 2, D.L. Allaix1, 2
1 TNO, Department of Structural Reliability, Delft, the Netherlands
2 Ghent University, Faculty of Engineering and Architecture, Department of Structural Engineering, Belgium
Traffic load models like in the Eurocode and other design standards are mostly calibrated using traffic load measurements at heavily loaded highway locations. Therefore application of these models to existing bridges in the urban road network often leads to unnecessary strengthening. Direct measurement data for this road network are currently not available in the Netherlands. Therefore in this study, a database with traffic load measurements at a highway location is first filtered to obtain the traffic load properties of roads in the urban road network. Subsequently a reliability-based calibration method is setup to calibrate a new traffic load model. This has led to a modified Eurocode EN 1992-1 LM1 and LM2 load model for the urban road network for the Dutch design situation. It was shown that the single and tandem axle loads of the LM1 and LM2 model could be reduced. The uniformly distributed load for the first lane had to be increased for the short spans relevant for the urban road network.
Key words: Traffic loads, urban road network, existing bridges, reliability-based calibration