A Theoretical Treatment of Crowd–Structure Interaction

A vertical crowd–structure interaction model including the interaction amongst pedestrians is developed to study the structural performances of the supporting structure with social force effect. This model can be used to analyze the vibration problem of footbridge under a large crowd excitation. The social force is firstly introduced to describe the dynamic interaction amongst the bipedal models with damping-spring legs modeling pedestrian movement on a three-dimensional plate structure. The social force determines the walking direction and velocity of pedestrian. Numerical studies show that the structural dynamic performances can be remarkably changed under the crowd action. The natural frequency of structure is decreased and is time-varying with an increase in the crowd density. However, the damping ratio of structure is increased. The proposed model could well describe the crowd–structure dynamic interaction.