A statistical approach to traffic loading on highway bridges

A study of the structural effects caused by traffic loading on highway bridges is presented. The objective is to provide guidance for the selection and calibration of the highway live loads, which are specified for design. Bridge loading events with one, two, …, five trucks present are simulated separately in five categories. The results are combined to form a probability distribution for each effect. The idealized trucks used in the simulation procedure are mathematical models of 6380 trucks that were weighed and measured during the 1975 truck survey in Ontario. For each effect, the mean largest value and the corresponding coefficient of variation are calculated based on two traffic densities. The largest effects caused by truck queues in traffic jams are predicted also.The effects are divided into three groups based on their sensitivity to multiple presence. For the first and third groups, the largest effects are caused by loading events with one truck and a queue of trucks respectively. For the second group, loading events with two trucks present may be the dominant cause of large effects. In the calibration process the magnitudes of live loads are adjusted in order that their application causes effects approximately proportional to mean largest effects.