A nonlinear analysis for the lateral girder response of footbridges induced by pedestrians

This paper presents a nonlinear analysis for the motion of equations proposed by Nakamura to predict the lateral girder response induced by pedestrians on footbridges. The relationship between the lateral vibration of footbridge and the coefficients in Nakamura´s model, including the rate of a pedestrian´s lateral force, pedestrian density, rate of synchronized pedestrians, and pedestrians´ attitude to large vibration amplitude, has been revealed, the simulation results demonstrate the validity of our theoretical analysis. The influence of the function to describe how pedestrians synchronize with the bridge natural frequency in Nakamura´s model on lateral vibration of footbridge has been known. Our result shows that pedestrians are not always most likely to synchronize at the bridge frequency around 1.0Hz.