A first step towards the development of load models for the vibration serviceability assessment of footbridges under running actions

The state of the art involving dynamic running actions is limited to single-person load models valid for running on a rigid laboratory floor. Little to no expertise is available on running excitation as a load scenario for civil engineering structures. The development of realistic load scenarios requires input on (1) intra-person variabilities, (2) inter-person variabilities and (3) human-structure interaction phenomena, and their impact on the resulting structural response. This contribution uses vibration measurements on the lower back of running persons to identify and characterize intra- and inter-person variabilities of the dynamic running load. Based on these results, the impact of these variabilities on the resulting structural response is investigated numerically. The results show that as the impact of intra-person variability is negligible, it can be disregarded in design calculations. However, the impact of inter-person variability is shown to be considerable, reducing the resulting structural response with 64% and more. Realistic ranges of inter-person variability should therefore be considered in design calculations.