Mitigation of human-induced lateral vibrations on footbridges through walkway shaping

In the last decade, the issue of human-induced lateral vibrations on footbridges has attracted an increasing interest due to the construction of several lightweight and flexible structures, which are highly sensitive to dynamic pedestrian action. A new approach to the mitigation of human-induced lateral vibrations on footbridges is proposed. The approach develops from the analogy between crowd- and wind-structure interaction phenomena. The mitigation measure addresses the passive control of the crowd flow and the applied force in turn, in analogy to aerodynamic countermeasures already adopted in Wind Engineering. Crowd flow control is accomplished by shaping the walkway in plan, in order to modify the pedestrian density, speed and walking frequency. A simplified approach to the preliminary assessment of the footbridge and to the conceptual design of the modified walkway is first proposed. A detailed computational analysis is subsequently applied to a test-case to evaluate the effectiveness of the proposed approach.