A novel and generic methodology for In-Field Motion tracking and application for the development and validation of models for Crowd-induced loading on footbridges

As materials become stronger and structures lighter, they become more lively under human-induced loading. Hence, vibration serviceability is becoming a key design criterion, rapidly replacing the ultimate limit state when determining the shape and dimensions of footbridges, (public) buildings and grandstands. However, the currently available load models are oversimplified and disregard the ever more important human-structure interaction effects, thereby preventing the targeted optimal structural designs. The further development of these load models is essential to avoid over-conservative designs as well as costly retrofits. This project aims at developing a methodology for the characterisation of crowd-induced loading based on the identified in-field human body motion. To this end, an innovative and interdisciplinary experimental approach is taken, combining state-of-the-art computer vision and individually-adopted sensor technologies. To allow for a more accurate representation of crowdinduced loading, the objective is to identify the individual key load features as well as the global crowd behaviour. The envisaged methodology will enable the characterisation of representative operational loading data, thereby constituting a significant breakthrough paving the way for the realistic description of crowd-induced loading. Based on a comprehensive numerical and full-scale experimental study, the goal is to arrive at validated load models for footbridges.